Support / FAQ

Before you look any further, make sure that you are running the latest version of PTGui. The current version is 9.1.9. See the version history for possible bugs that have been fixed in recent versions. If you are a registered user, you can upgrade at a reduced price, or free of charge, depending on the date of your original order.

Documentation and Tutorials

The Video Tutorial on this site should help you get started using PTGui. Tutorials for advanced usage of PTGui can be found on the Tutorials page. And the Links page contains links to more tutorials, written by users of PTGui.

Detailed documentation for every feature and parameter is available in the on line help: in PTGui choose 'Help -> Help for this tab'.

Getting support

If you have a question or problem please first check the list of frequently asked questions below. The answer to your question may already be listed there.

If this does not solve the problem you can get support as follows:

Technical support forums

Please post your technical support questions to the PTGui Group. You will quickly get an answer from the PTGui authors or from other users. This forum is hosted at Google; to post a message you need to login with your Google Account, or follow the instructions to create a new account.

The PanoToolsNG Group is an active community dedicated to panoramic imaging, not specific to PTGui. This is a good place to discuss technique and equipment for panoramic photography.

Contact us

For non-technical questions (e.g. related to purchasing, registration keys, downloading) please contact us directly at email support.

Frequently asked questions

1. Ordering

1.1. I lost my registration code
1.2. I tried to enter my registration code, but it doesn't work
1.3. I purchased PTGui or PTGui Pro and I still haven't heard from you after a day!
1.4. I have purchased a PTGui license a couple of years ago. How can I upgrade to the latest version?
1.5. I am a licensed user of PTGui; can I upgrade to PTGui Pro?
1.6. What's the difference between PTGui and PTGui Pro?
1.7. Where can I find the license conditions for PTGui / PTGui Pro?
1.8. Do you offer special student pricing?
1.9. Can I install PTGui on both my PC and my laptop computer?
1.10. I'm planning to switch from a PC to a Mac computer, is that a problem?
1.11. How can I remove a PTGui license from my computer, or how can I transfer my license to another computer?
1.12. I need to reinstall PTGui but my license is not valid anymore for the latest version. Can I still download older versions?
1.13. My organization needs a pro-forma invoice before we can purchase a license. Can you arrange this?
2. General questions

2.1. Does PTGui require Adobe Photoshop?
2.2. Does PTGui require Panorama Tools?
2.3. Is PTGui or the documentation available in other languages?
2.4. My lens database is empty, is that normal?
2.5. Can PTGui work with 16-bit images from start to finish (ie, no 8-bit conversion)?
2.6. Can PTGui create virtual tours?
2.7. When I change the image orientation (landscape vs. portrait) or the focal length multiplier, the focal length value changes. Why?
2.8. Sensor sizes: millimeters vs inches?
2.9. When I crop an image (using the Crop Tab in PTGui), the image appears to be enlarged in the Panorama Editor. Why?
2.10. My images were taken with a (e.g.) 28mm lens, but after optimization, PTGui reports it as a 31.5mm lens
2.11. Can I mix images in portrait and landscape orientation in one panorama?
2.12. Can PTGui read RAW/DNG files?
2.13. What does 'Apply Template' do?
2.14. Apply Template does not copy the control points from the template. Why is that?
2.15. Does PTGui support multiple processors?
2.16. What kind of computer hardware do you recommend for use with PTGui?
2.17. PTGui doesn't seem to use all available memory on my computer. Can I force it to use more RAM to speed up the stitching process?
2.18. Does PTGui preserve the EXIF data of my images?
2.19. Can I stitch images from a shift lens with PTGui?
2.20. Does PTGui run on my version of Windows / OS X
2.21. Where does PTGui store its settings?
2.22. PTGui doesn't fully use my computer's processor(s); the CPU load is less than 100% during stitching
2.23. After optimizing, PTGui shows me the average control point distance. What distance should I aim for?
2.24. I have tried the Panorama Tools optimizer and it gives me lower control point distances. Why?
2.25. Is there a 64 bit version of PTGui?
2.26. Why does PTGui Pro close my project and open a new blank project after I press Save and Send to Batch Stitcher?
2.27. PTGui asks me whether I would like to re-initialize the project. What does this mean?
2.28. Can PTGui create those interactive photos where the camera is rotated around the object?
2.29. After stitching a project in the PTGui Pro Batch Stitcher, the project is modified!
2.30. I have edited my RAW / DNG files in Photoshop or another application. Does PTGui recognize my changes when I use the raw files in PTGui?
2.31. What can I do to reduce the stitching time PTGui on my system?
2.32. I have moved or rotated images in the Panorama Editor by hand using the Edit Individual Images mode. But PTGui tells me it needs to optimize the panorama and this undoes my changes. Why?
2.33. Do you have documentation for the PTGui project file format?
3. Troubleshooting

3.1. After aligning the images, the preview in the Panorama Editor looks completely garbled
3.2. I am trying to edit the seams of a layered panorama in Photoshop, but I only see the bottom layer with the merged panorama; the other layers are transparent.
3.3. I'm having trouble stitching images taken with the Sigma 10-20mm / Tokina 12-24mm / Nikkor 10-24mm lens
3.4. The panorama created by PTGui is too small, I'm loosing image resolution.
3.5. After optimization, the 'distance' column in the Control Points table is empty for one or more control points
3.6. PTGui crashes upon startup on Mac
3.7. Another application crashes when opening TIFF files generated by PTGui, or it displays garbled images.
3.8. PTGui continuously locks up for a few seconds and then becomes responsive again.
3.9. Drag and drop doesn't work with PTGui on Windows
3.10. I'm having trouble stitching images taken with the Nikon 16mm fisheye lens
3.11. My computer crashes occasionally while PTGui is running
3.12. I'm trying to view a QuickTime VR panorama generated by PTGui but all I see is a black or transparent window.
3.13. My images have a different brightness or color when viewed in PTGui
3.14. PTGui shows a message 'PTGui was unable to detect control points for some of the images, therefore you need to add a few control points by hand'. Help! What should I do now?
3.15. PTGui is randomly rotating my images!
3.16. I'm having trouble stitching my panorama. Can you help?
3.17. Norton / Symantec antivirus says there's a virus in the PTGui installer!
3.18. When stitching a very large panorama on a Mac, PTGui aborts with the error message 'Too many open files'
4. Improving the results

4.1. The horizon of my panorama is curved instead of straight
4.2. I get color/brightness differences between the images in my panorama
4.3. How can I change the resolution (ppi or dpi value) of the generated panorama?
4.4. I see misalignments in the stitched panorama. What can I do to improve the result?
4.5. Some control points in my project have a relatively high control point distance. Will the alignment of my panorama improve if I delete all control points with an error above a certain threshold?
5. How to...

5.1. My panorama contains curved lines. How do I get straight lines to remain straight in the panorama?
5.2. How to create cubic QTVR (Quicktime VR) panoramas
5.3. How do I use the Horizontal line and Vertical line control points?
5.4. How can I calibrate my lens parameters?
5.5. Does PTgui allow stitching of photos that have the camera in different locations?
5.6. How can I stitch mosaics, like partial scans from a flatbad scanner of a large image?
5.7. My panorama was taken with the camera tilted up or down. Now there's a lot of unnecessary black space above/below the panorama, increasing the size of the output. Can it be cropped away before stitching?
5.8. How can I have better control of the overlap area (i.e. the location of the seams)?
5.9. How can I create a vertical panorama? PTGui rotates my panorama 90 degrees!
5.10. I want to cover the tripod in my (360x180 degree) spherical panorama. How do I add a nadir cap?
5.11. How can I change the default settings for new panoramas?
5.12. How can I stitch extremely large panoramas?
5.13. How can I align a set of images, all taken in the same direction (not a panorama)?
5.14. How can I use exactly the same stitching settings for different sets of images?
5.15. Can I stitch images taken with different lenses or different zoom settings in one project?
5.16. How can I correct a single image for lens distortion?
5.17. How can I show a 360 degree panorama on my website?
5.18. How can I show a high resolution panorama on my website?
5.19. How do I level/straighten a panorama using horizontal / vertical line control points?
5.20. How can I correct a single image for vignetting in PTGui Pro?
5.21. How can I retouch the nadir or zenith of a stitched panorama?
5.22. I would like to create a QTVR in PTGui, but it needs some retouching in (e.g.) Photoshop. How can I do this?
5.23. My spherical panorama still has a hole in the top and/or bottom. How do I fill the missing parts to make the panorama truly spherical?
5.24. After running Publish to Website my panorama has black holes at the top and bottom; how do I get rid of these?
5.25. PTGui leaves some blank space around my panorama. How can I crop the panorama so that it fills the canvas entirely?
5.26. I would like to generate panoramas of a certain size, but PTGui has changed the output size after I did Align Images. How can I tell it to keep the panorama size set in the Create Panorama tab?
5.27. How can I defish a fisheye image in PTGui?
5.28. How can I extract a 'flat' image from a spherical panorama?
5.29. I have taken multiple panoramas from the same viewpoint, to create a time lapse movie. How can I ensure that subsequent panoramas are aligned when played back in sequence?
5.30. My project contains one or more images without any recognizable detail and it's impossible to place control points. How can I stitch my panorama?
5.31. How can I view a finished panorama interactively on my computer?
5.32. I would like to send a panorama to a friend/client/... Is it possible to view a panorama interactively without needing to install a plugin first?
5.33. I need to align/overlay an image to an already stitched panorama. How can I do this?
5.34. How can I stitch a PTGui project from the command line?
5.35. Can I use PTGui to arrange pictures into a collage? Can I disable the warping/distorting of images?
5.36. How can I display spherical panoramas on my iPad?
5.37. How can I stitch panoramic video in PTGui?
5.38. Is there a way to stitch many panoramas using the same settings?
5.39. How can I make 'little planet' images in PTGui?
5.40. How can I stitch images from Adobe Lightroom in PTGui? Do you offer a Lightroom plugin?
6. PTGui Pro and HDR

6.1. What is the best way to take images for HDR stitching in PTGui Pro?
6.2. My images don't contain EXIF exposure information. Can I still use them to stitch HDR panoramas?
6.3. PTGui Pro doesn't recognize my bracketed exposures!
6.4. The stitched HDR panorama looks like it was not blended at all. I'm seeing hard edges between overlapping images.
6.5. So I forgot to switch my camera to M mode; my bracketed images are taken in auto exposure mode. Can I still stitch them to HDR in PTGui Pro?
6.6. Why should I use manual exposure mode? Isn't it much better to use automatic exposure, so that every image is optimally exposed?
6.7. PTGui Pro displays the wrong EV values! My images were taken at -2, 0, +2. This is confirmed by the EXIF data but PTGui shows something else in the Image Parameters tab.
6.8. What's the deal with linked images?
6.9. Should I link my bracketed exposures or not?
6.10. Can I retouch an HDR panorama, e.g. to remove ghost images of moving people?
6.11. I would like to stitch my panorama in PTGui Pro, but use another application (e.g. Photomatix or Photoshop) to create the HDR.
6.12. I've chosen a 16 bit file format for my HDR output and the generated output is very dark. Why?
6.13. The panorama editor only displays the brightest (or darkest) of my bracketed images, which makes it difficult to preview the final result.
6.14. Can I use PTGui Pro for exposure fusing / tone mapping / HDR generation of non-panoramic images?
6.15. Can I extract artificial bracketed images from my (non bracketed) RAW files and have PTGui Pro assemble those into an HDR panorama?
6.16. I have read the previous answer but I still would like to stitch my pseudo bracketed images generated from RAW files!
1. Ordering

No problem; we can resend your registration key to you. The registration key is quite long and it is easy to make mistakes when trying to manually type it. Instead it's much easier to copy the registration code from your order confirmation email by selecting the code and pressing CTRL+C, and paste it into PTGui using CTRL+V (Mac users use Command+C and Command+V instead).

The registration key and registration name are linked to each other. Be sure to enter the correct registration name: it may be different from your own name. The registration name is shown in the order confirmation email as well.

If you don't have the registration key anymore, we can resend it to you.

A correctly entered registration key would look as follows:

We send you your registration key as soon as possible after receipt of your payment, though this may take up to 24 hours. If you still haven't heard from us after that time, be assured that we did send you your registration key but apparently our email has not reached you. This occasionally happens, often caused by spam filter problems or full mailboxes.

If your mailbox has a Junk Mail folder, look for mail from PTGui Support <support@ptgui.com>. Many junk mail filters have a white list feature (often called 'trusted senders'); please add our address to it.

Then go to this page to get your key: Request registration key Every PTGui and PTGui Pro license comes with one year of free upgrades. After that year you can purchase an upgrade license at a discounted price, which includes another year of free upgrades. See Order upgrade for more information. Yes, you can upgrade from PTGui to PTGui Pro at a discounted price. See Order upgrade for more information. See Features of PTGui and PTGui Pro. See: End User License Agreement No, sorry, we do not offer educational or any other kind of discounts on individual license purchases. We do offer discounted company licenses to universities and schools, please contact us for details. A personal license may be installed on up to three computers, provided it is only used by the person to whom it is licensed (i.e. the name appearing in the registration key). If multiple users use PTGui on those computers, multiple personal licenses or a company license should be purchased instead.

For the company license registration keys are issued on a per machine basis: a separate registration key must be purchased for each computer on which the software is installed.

Other restrictions apply; see the End User License Agreement for details. No problem, you can just download the mac version of PTGui using your existing registration key. The license is platform independent. To remove a PTGui license: start PTGui and go to Help -> About -> Register (on Windows) or PTGui -> About -> Register (on Mac). Then click on Deactivate. After this the registration key is removed and PTGui will close.

To transfer your license to another computer you can remove the license from the first computer as described above, then install the software on the new computer using the original registration key. Yes, several older versions of PTGui and PTGui Pro are still available. To download, go to the Download page, choose 'Download full version' and enter your registration key. On the subsequent page click on the 'older versions' link to access the latest version of PTGui for which your license is valid.

Alternatively, consider to upgrade to the latest version. See Version History for what's new in the latest version. As a licensed user you are entitled to discounted upgrade pricing. Yes, this is possible: Go to the Order page at this site and press the Buy Now button of the desired product. On the subsequent page choose: Payment Method: Check (or Bank/Wire Transfer if available). After filling in your personal details you will be transferred to ShareIt's website. Complete the order forms until the order is finalized. You will be sent a pro forma invoice with payment instructions. If you later on decide to pay by credit card instead, just place a new order through our website. The wire transfer order will be canceled automatically if no payment is received within a month.
2. General questions

No. Although Photoshop users can benefit from the layered Photoshop output of Panorama Tools, it is not required to run PTGui. No, Panorama Tools is not required. Although PTGui originally started as only a user interface for Panorama Tools, today it is a full featured stand alone stitching software.

But you can still use Panorama Tools with PTGui. No, currently PTGui is available in english only. But on the Links page you will find some links to tutorials in other languages. Yes, it is. You can use it to store your optimized lens data. Yes, PTGui performs all image processing in 16 bit if a 16 bit output format is selected on the Create Panorama tab. PTGui Pro even supports 32 bit floating point images. This depends on how you define a 'virtual tour'. Yes, PTGui can create interactive panoramas using the Publish to Website tool. See an example here. Such an interactive panorama is created in PTGui in two steps: first the panorama is stitched into a 'flat' panoramic image in jpeg or tiff format. Then this image is converted into an interactive panorama through Tools -> Publish to Website. In the window that appears press the Help button for more information.

But commonly the term 'virtual tour' refers to a presentation consisting of multiple such panoramas, linked by hotspots or a clickable floor plan. To create such a tour you will need additional third party software. See Q5.17 for recommendations.

Most of the panorama viewers mentioned in Q5.17 can create virtual tours by linking the panoramas using hotspots. In Pano2VR and Flashificator authoring is done in a graphical user interface, while for the other viewers knowledge of XML and/or JavaScript is required. Internally in Panorama Tools and PTGui, lenses are characterized by their horizontal field of view, not by the focal length. If you replace a portrait image by a landscape image, still the same horizontal field of view is used, but because the aspect ratio has changed, the same field of view corresponds to a different focal length. In that case simply re-enter the right focal length. The same applies when you change the value of the multiplier. In the EXIF window, PTGui will show you the size of the optical sensor in millimeters (if the data or your camera is available). Most manufactures however will state the sensor size in fractions of an inch (e.g. 1/2.5"). The inch-designation dates back to TV camera tubes in the 50s and it does not appear to be mathematically related to the actual sensor size. For more information, read Sensor Sizes at DPReview.com When the Crop Tab is used to crop an image, the field of view value (on the Lens Parameters tab) is the field of view of the cropped portion of the image (and not the field of view of the original image). Since cropping does not alter the field of view of the visible part of the image, the cropped portion of the image will take the same space in the panorama as would the uncropped image. So cropping effectively zooms into part of the image.

The Crop Tab is intended to be used for lenses that use only part of the film/ccd plane, or for scanned images, where the scanned area is larger than the actual image. Generally, all images in a project should have the same crop size, unless individual lens parameters are used for the cropped image(s).

If your goal is to exclude certain unwanted parts of a source image from the panorama, don't use the Crop Tab. Instead, stitch the panorama to a layered format, and use an image editing program such as Photoshop to hide the unwanted parts, after stitching. Or, alternatively, remove the unwanted parts from the image prior to stitching, by making the area in the source image transparent. This requires source images in TIFF or PNG format, which support transparency. The optimizer adjusts your project in such a way that the lowest control point distance is obtained. This may include modifying the field of view / focal length of the lens (if selected for optimization). There can be several reasons for the difference: Since the optimized value corresponds to the lowest control point distance, the value determined by the optimizer will generally result in the best alignment of the images. This is not recommended, since the Project Assistant of PTGui expects all images to have the same aspect ratio (and hence the same orientation). This is due to the fact that lenses are characterized in Panorama Tools (and PTGui) by the horizontal field of view, and the Project Assistant attempts to optimize the horizontal field of view of all source images to a single value.

Therefore, if you want to mix portrait and landscape images, you currently need to rotate all landscape images or all portrait images in a graphics editing program, prior to loading in PTGui, so that all images in the project have the same orientation. The Project Assistant will be able to determine the original rotation of the images and rotate those images back to their original orientation in the panorama.

[actually it is possible to stitch mixed portrait and landscape images in PTGui without rotating images first, by using 'individual lens parameters'. However, this is considered advanced use, and is not supported by the Project Assistant] Yes, PTGui can read RAW files of many cameras and DNG files through the bundled dcraw application. Please note that RAW files are not regular image files; rather they can be seen as a digital 'negative' which first needs to be developed to get the actual image. This development is done using standard settings, although PTGui Pro does allow you to adjust exposure and white balance in the HDR/Exposure tab.

If you need more control, use a dedicated RAW converter instead and save the converted RAW files as 16 bit TIFF images. This preserves the image quality and full dynamic range of the source images. Be sure to convert all source images in a panorama using the same settings, otherwise color or brightness differences may remain visible in the panorama.

Please note that any adjustments made to the RAW file in Photoshop RAW (or other RAW converters) are ignored by PTGui. These programs do not actually change the RAW file; instead they write the modifications to a so-called sidecar (.xmp) file. The sidecar file contains closed proprietary data and cannot be read by other software.

Therefore, if you need to make changes to RAW files, save the resulting images to 16 bit TIFF files and load those in PTGui instead of the original RAW files. This copies the settings of another project to the current project, except for the images and the control points. This function is accessible both from the 'Apply Template' item in the File menu, and from the toolbar in PTGui. A template can be any PTGui project. In Tools/Options/Folders&Files, a folder can be configured where you store your templates (on Mac go to the PTGui menu, Preferences, Folders&Files). Then, the template selection dialog will by default open in this folder. There's a little triangle button next to the 'Apply Template' button on the toolbar, which shows a drop down list of all templates in the configured template directory, for quick access.

Templates can be useful for a quick initialization of a project (lens settings, rough alignment of images), although this is usually not necessary since the Project Assistant can figure out the alignment of the panorama by itself.

Another use for templates is when you have an exact reproducable setup (high quality panoramic head with fixed angles). In this case you could copy all settings of a previous project and there would be no need for placing control points and optimizing.

By default, applying a template copies all settings from the template to the current project except for the source images and the control points. In PTGui Pro this behaviour can be modified in the Project Settings tab, section 'template behaviour'. By default applying a template copies all settings from the template except for the actual source images and the control points (see Q2.13). Control points are never copied since they are specific to the source images. For example a control point could originally point to the corner of a building in the template project, but in another project the same coordinates may be in the middle of plain blue sky. In other words the control points are meaningless outside the context of the original images.

If you just need a project to be stitched exactly like the template project, control points are not needed at all. Control points are only used by the optimizer to determine the best image parameters. The stitcher then only uses the image parameters, not the control points. Therefore it's sufficient to apply the template and proceed straight to Create Panorama without running the optimizer. Yes, PTGui supports computers with multiple processors (also called multi core systems). During stitching and control point generation work is split into multiple parallel running tasks. On multi core systems, several of these tasks run simultaneously on multiple processors, thus increasing speed. But keep in mind that the processor is not the only speed limiting factor. Stitching requires a lot of disk I/O and memory access. Therefore, doubling the number of processors will not actually double the speed. PTGui will run fine on an older computer with 1 GB of RAM, and it is even possible to stitch very large panoramas on such a system. The only things you really need for large panoramas is patience, and lots of free hard disk space for temporary storage. You can see how much temporary disk space is required for a project by choosing 'Calculate required temporary disk space' in the Project menu of PTGui. For large panoramas, this can be several gigabytes.

PTGui will at first attempt to use physical RAM memory for temporary storage. Once all available RAM is exhausted, temporary data will be written to disk. Since hard disk access is much slower than RAM access, stitching speed will benefit from the availability of enough RAM. Due to operating system limitations, the 32 bit version of PTGui can only access 2 Gigabytes of RAM. If you have more RAM you need the 64 bit version of Windows, or a Mac capable of running 64 bit applications.

If you intend to stitch very large panoramas (requiring more temporary storage than available RAM), use an SSD for temporary storage. Internal SATA harddisks are usually much faster than external USB or Firewire disks. You can configure which drive PTGui uses for temporary storage in Options/Preferences (in the Folders & Files tab).

Finnally a faster processor will of course result in faster stitching. PTGui is designed for multi core processors: a stitching job is split into multiple tasks running concurrently on multiple processors. But often the processor is not the bottleneck; if you have the choice, get extra RAM instead of a faster processor.

There are no video card requirements; PTGui does not use graphics acceleration. In Options/Preferences, section Advanced, the maximum amount of RAM memory to be used can be configured. This is an upper limit though: PTGui will never use more than the configured amount, but it cannot be forced to use all of it. Even if it would be possible to force it to use more RAM, this would not speed up the stitching process.

Regardless of the configured amount of RAM or the size of the panorama, all temporary storage is always backed by temporary files. These temporary files are created in the temporary folder(s) configured in Options/Preferences (Folders & Files tab). Temporary files are cached in RAM; therefore they are read and written at the fast speed of RAM instead of the slow speed of the hard disk. As long as the total size of temporary storage stays below the configured maximum amount of RAM temporary data is just slowly flushed to the temporary files in the background. Only once all RAM becomes exhausted temporary data will be written straight to disk.

Due to this mechanism PTGui may actually be utilizing more RAM than indicated by Task Manager. For the caching to work properly it's important to have write caching enabled for the disks on which the temporary folders are located. For internal hard drives write caching is enabled by default; only if you are using an external USB disk on Windows you need to ensure write caching is enabled by selecting 'Optimize for performance' in the properties of the external drive. Currently, the following metadata is copied to the generated panorama: For rectilinear panos, PTGui also adds the FocalLength and FocalLengthIn35mm tag.

For HDR panoramas in PTGui Pro, the 'blend planes' output contains the exposure/iso/aperture of that particular exposure, for merging in external software.

Other EXIF data is currently not copied to the output file. Metadata is only written to JPEG and TIFF images, not to Photoshop files. First of all, you don't need a shift lens if you have PTGui! Shift lenses are often used for architectural photographs: photographing a building from ground level, while tilting the camera upwards, normally results in converging vertical lines. Shift lenses compensate for this effect by shifting the optical axis of the lens relative to the center of the image plane. The result is a photograph where parallel lines remain parallel.

The same effect can be achieved in PTGui: open the Panorama Editor window, press Ctrl-P to switch to 'Panorama Edit' mode. Now drag the panorama upwards or downwards until parallel lines in the scene are parallel in the panorama. You may need to increase the vertical field of view (using the slider to the right of the panorama).

If you do want to stitch images taken with a shift lens in PTGui, change the following parameters: Regardless whether a shift lens is used, or the panorama was shifted in the Panorama Editor, you will end up with some black space below or above the panorama. This can be removed by dragging yellow crop lines from the edges of the panorama in the panorama editor. The process is shown in detail in part two of our Video Tutorial. PTGui runs on Windows XP and all newer Windows versions. For Windows XP, service pack 3 is required. Both the 32 and 64 bit Windows versions are supported: the PTGui installer will automatically install a 64 bit version of PTGui when possible.

PTGui for Mac only runs on Intel processors and requires OS X 10.5 or later. The configuration file for PTGui is:
C:\Users\<user>\AppData\Roaming\PTGui\Configuration.xml (Windows Vista and 7)
C:\Documents and Settings\<user>\Application Data\PTGui\Configuration.xml (XP)
/home/<User>/Library/Application Support/PTGui/Configuration.xml (Mac)

Other configuration data (such as the lens database) is stored in the same folder. When moving a PTGui installation to a different computer, it's sufficient to move only this folder to the new computer. PTGui does not use the Windows registry. Stitching and blending requires a lot of disk and memory access. In particular for large panoramas, or on multicore computers, not the processor but the hard disk is the speed limiting factor. The stitching speed can be increased by installing a faster hard disk or a RAID array of multiple hard disks. The control point distance indicates how well a control point pair aligns in the panorama. When the distance is zero, the two points of a control point pair overlap exactly.

One should aim for the lowest control point distance possible, but the actual lowest distance that can be achieved depends on many factors. In general if your images were shot properly using a tripod with calibrated panorama head, a control point distance well below 5 should be achievable. Most remaining misalignments can usually be masked by the blender. An average distance higher than 5 usually indicates a problem, see Q4.4 for solutions.

It's particularly important to look at 'outliers': if a control point has a distance of 20 while the average is below 5, this control point might have been placed on a moving object, or on a similar feature close to the proper location. Use the 'Delete worst control points' function (in the Control Points menu) to remove such outlying control points. Both optimizers work in much the same way and they adjust the same set of parameters. However, different optimization criteria are used. The Panorama Tools optimizer minimizes the distance of the control point pair in the panorama: the two points of a control point pair are projected into the panorama and the distance is measured. The PTGui optimizer minimizes the distance of the control point pair in the source image space: the first point of a control point pair is projected into the second image and the distance (in source image pixels) is measured.

Due to the different criteria, the numerical results are different, but the actual quality of optimization is nearly identical in most cases.

By optimizing the distance in the source images (instead of in the panorama), the PTGui optimizer is better able to do a stable optimizion of the field of view in partial panoramas. Additionally, the PTGui optimizer can optimize very large panoramas (say 100 source images or more) much more efficiently than the Panorama Tools optimizer and it supports viewpoint optimization (Pro version only). Yes, all versions of PTGui are available in 32 and 64 bit releases.

For Windows we offer a single PTGui installer. This automatically installs the 64 bit version of PTGui if the Windows version is 64 bits, otherwise the 32 bits version is installed.

The Mac version is a universal binary for both 32 and 64 bits. If your mac is capable of running 64 bit applications (most machines from 2007 onwards are) PTGui will run in 64 bit mode. The Batch Stitcher of PTGui Pro can generate control points; it will do so if instructed by the 'Do Align Images and save the modified project' checkbox in the Project Settings. By default this is enabled if the control point generator has not yet been run for the project. This allows you to quickly generate a panorama in batch: start a new project, load your source images and press Save and Send to Batch Stitcher. The batch stitcher generates control points and stitches the panorama in one go.

After generating control points and aligning the images the batch stitcher overwrites the project file with the modified version. Since the Batch Stitcher will modify the project file, problems could occur if the project would remain opened at the same time in the main PTGui Pro window: both instances would be writing to the same project file, discarding each other's changes.

For this reason, PTGui Pro will close the project after sending it to the batch stitcher if the Batch Stitcher is configured to modify the project. This ensures that only one instance of the project is open. A warning message is shown before the project is closed but the warning is no longer shown if 'don't show this again' had been selected. To re-enable the warning message, go to Options/Preferences and click 'Reset all warning messages'.

In previous version of PTGui, a temporary copy of the project would be sent to the batch stitcher. This functionality is still available through 'Send Temporary Copy to Batch Stitcher'. This creates a copy of the current state of the project in a temporary file, which is sent to the batch stitcher for stitching. When stitching has finished the temporary project file is deleted by the batch stitcher. If PTGui fails to properly align your images, the following question may appear:

"The optimizer failed to achieve a good alignment of the images. Possibly the current misalignment of the images causes the optimizer to get stuck. Re-initialization of the project may help in such a case. Would you like to re-initialize the project and try to optimize again?"

If you click OK, PTGui will reset the yaw, roll and pitch of all images to zero and reinitialize the lens settings based on the EXIF data. Then it will attempt to figure out the image positions from scratch and subsequently reoptimize the project.

In particular in cases where the optimizer got stuck in a so-called local minimum such an initialization from scratch can be the solution.

This function can be triggered manually using the Initialize and Optimize (in the Project menu). These are commonly called 'Object Movies'; they cannot be created through stitching and therefore PTGui does not support this. A software package for creating object movies is Object2VR. The batch stitcher of PTGui Pro can not only stitch projects, but it can also set up a new panorama project by generating control points, aligning the images, etc. It will do so if instructed by the 'Do Align Images and save the modified project' checkbox in the Project Settings tab. If the project or template is already set up completely and the panorama should only be stitched, make sure that the above checkbox is unchecked. No, PTGui will load the raw files as they came straight from the camera, any modifications are ignored. In Photoshop RAW files can be edited, but the changes are written to a 'side car' file (with the .xmp extension) rather than to the original raw file. The settings in the side car file are specific to the algorithms used by Photoshop and cannot be used by other applications.

To use the modified RAW files in PTGui, export them to 16 bit TIFF files and load those in PTGui instead. Since RAW files typically only have 12 or 14 bits per channel, the full dynamic range will be preserved by the 16 bit TIFF file, so there is no loss of quality. The time required to stitch a panorama is influenced by many factors, such as the dimensions of the panorama, the computer hardware and by other applications running at the same time. Some general hints to improve the stitching performance: You should not attempt to align images manually: it's impossible to get the required precision for a seamless stitch. Even if you would manage to accurately align an image to one neighbouring image, this would trow it out of alignment with its other neighbour images.

Instead you should let the PTGui optimizer do all the hard work through control points. Control points tell PTGui which points of two images should overlap. By providing 3 or 4 control point for a pair of overlapping images, PTGui will know how they overlap and the optimizer will align the images with pixel accuracy.

For more information watch our our Video Tutorial. We don't support the use of PTGui project files in other applications, therefore we don't offer any documentation. PTGui may crash or produce other undesired behaviour when loading project files generated by other applications. And the file format may change with every update.

That said, PTGui project files are simple text files based on the PTStitcher script syntax. It's easy to take an existing project file and modify it to suit your needs.

Note that this applies only to the full version of PTGui. The trial version generates encrypted project files, to prevent circumvention of the trial limitations.
3. Troubleshooting

If this happens, it is usually caused by the control point generator adding control points between unrelated images. This can happen in particular with panoramas taken in a completely symmetrical room. Although PTGui can handle images with repeating or identical structures, if your images contain large areas with identical contents on different sides of the panorama, the control point generator may get confused, and add control points between unrelated images, for example between opposite walls.

The solution is to manually review the control points. This can be a tedious process, especially if the panorama consists of many images. Go to the Control Points tab. Select the first image (image 0) in the left pane. The numbered tabs in the right pane will be shown in a bold font if there are control points between the image selected in the left pane and the image in the right pane. In the right pane, go through all the tabs with bold numbers, and check whether the two images really overlap. If the images are unrelated, delete all control points for those two images. This can easily be done by selecting all control points in the table at the bottom of the Control Points tab, and pressing the Delete key. Repeat this process by selecting the second image in the left pane, and so on.

Finally, choose 'Initialize and Optimize' in the Project menu. This will reset the project to its initial state and attempt to align the images from scratch. If all faulty control points have been removed, the result should now be a proper panorama. This is by design. The idea is to use the blended panorama as the basis for retouching, selectively revealing parts of the source images for retouching by making the masks opaque. See the post processing tutorial. When starting a new project PTGui initializes the lens parameters based on the EXIF data of the first image. The EXIF data contains information about the focal length of the lens and the size of the sensor in the camera. Besides the focal length PTGui also needs to know the projection of your lens. Most SLR lenses and all consumer cameras have rectilinear ('flat') projection, but some wide angle lenses have a fisheye projection.

Unfortunately, the EXIF data does not tell the projection the lens. PTGui therefore guesses the projection based on the focal length of the lens: SLR lenses with a focal length below 15mm are assumed to be fisheye lenses; higher focal lengths are assumed to have rectilinear projection. This is a good assumption in general, but these particular lenses are exceptions because they have a rectilinear projection. To stitch these images you need to override the automatic lens settings in PTGui as follows: If you don't use any fisheye lenses, you can configure PTGui to always assume rectilinear projection for your lens: go to Tools/Options (on Mac go to the PTGui menu, Preferences), EXIF tab and change the 15mm values to e.g. 9mm. From now on PTGui will assume any lens with a focal length higher than 9mm is a rectilinear lens. PTGui can generate a panorama at any size you desire. To do so, increase the width and height values in the Create Panorama tab before generating the stitched panorama. To get a panorama at the highest quality, press the 'Optimum Size' button and choose 'Maximum Size'. The resulting panorama will have approximately the same resolution (level of detail) as the original images.

The same applies to the Preview function: in the Preview tab, increase the width and/or height before generating the preview image. This has one of the following causes:
  1. This particular control point was disabled for optimization. Enable it by right-clicking on the control point and enable the 'Optimize' checkbox.
  2. All control points of a particular image were disabled for optimization, using the 'use control points of' list in the Optimizer tab.
  3. This particular control point was placed between two linked images in a HDR panorama. If two images are linked, they will be overlaid exactly and control points between the two images are ignored by the optimizer.
  4. This particular control point is a horizontal / vertical line control point. The PTGui optimizer only reports control point distance for normal control points.
PTGui requires at least OS X 10.5. It will crash upon startup when launched on OS X 10.4 or earlier. TIFF is a container format which can contain many different types of image data; almost no application supports all possible TIFF formats. PTGui can create 16 or 32 bit TIFF files and TIFF files with an alpha channel but these features are not supported by many applications. If you need create a compatible TIFF file, press the 'Settings' button in the Create Panorama tab, and choose: 8 bits, no alpha channel and no compression. The resulting file can be opened in nearly every application that supports TIFF files. This is a known problem with certain virus scanners, or it could be due to PTGui using more memory than is available.

PTGui stores image data in temporary files; these files are accessed continuously, for example when scrolling an image in the Control Points tab or when the panorama editor is updated. Most virus scanners feature 'on access scanning', where every file is scanned when an application attempts to access it. Scanning large files may take several seconds and the virus scanner suspends the application until scanning has finished. Therefore using on access scanning on PTGui's temporary will cause intermittent lockups.

If you see intermittent lockups in PTGui we therefore recommend to disable on access scanning for PTGui's temp files. By default PTGui stores temporary data in the Windows default temporary folder (C:\Users\<your name>\AppData\Local\Temp) but it's best to designate a dedicated folder for PTGui temporary storage. Create for example the folder C:\PTGuiTemp\. Then go to Tools - Options - Folders and Files - Temporary Folders and enter this folder name. Restart PTGui for the changes to take effect. In your virus scanner exclude this folder from scanning by your virus scanner. Please consult the manual of your virus scanner for more information.

A second reason for the lock up could be PTGui using more memory than is available. In Options / Preferences - Advanced you can configure the maxmimum amount of RAM PTGui will use as a percentage of the available RAM memory. If you have other applications running which also request a lot of RAM it's possible that all running applications together will request more than 100% of available memory. As a result the operating system will continuously be swapping RAM memory to disk and this will bring the entire computer to a crawl. To see if this is the case, reduce the configured amount of RAM significantly and see if this resolves the problem. Also close any other applications that might use a lot of memory (in particular image editing programs such as Photoshop). This problem may occur if you run PTGui as Administrator. In Windows Vista and Windows 7, dragging and dropping files is not allowed between applications running at different security levels. By default, PTGui assumes that any lens with a focal length above 15mm is a rectilinear (non fisheye) lens, while your lens is a full frame fisheye lens. Unfortunately it's not possible to tell the lens type from the EXIF data. To use these in images in PTGui make sure that the lens type is set to 'Fullframe' with a focal length of 16 mm. You can do this in the Project Assistant as follows: If you would like PTGui to do this automatically, go to Options/Preferences, EXIF tab and enter:
'- focal length is 16 mm or less, and focal length multiplier is less than 1.85'.
This changes the default lens type to fullframe for any lens of 16mm or less. A normal application like PTGui (i.e. not a driver or a kernel process) is unable to crash an entire computer; the worst that could normally happen is the application itself crashing but not the entire computer.

If the computer crashes, shows a 'blue screen' error or spontaneously reboots this is usually indicating a problem with the hardware or a driver. It's possible that you observe the problem only when running PTGui: stitching large panoramas places a heavy load on the processor, hard disk and memory. This could trigger any existing hardware problems for example due to the increased temperature of the processor, due to increased load on the power supply, or simply because any existing problem is more likely to be seen when the system is used intensively.

If you however observe crashes in PTGui but the operating system continues to run properly then this could be a bug in PTGui. The Windows version of PTGui includes a crash reporter; we encourage you to submit the crash data to us for analysis. Mac users please send the crash report to us at email support; crash reports on the Mac can be found in <User>/Library/Logs/CrashReporter/. This was a known issue in certain versions of QuickTime on 64 bit Windows platforms. The problem should be solved after upgrading to the latest version of QuickTime.

Alternatively you could use the DevalVR player which can display QTVRs on any Windows version. PTGui is currently not a color managed application, so it ignores any color profile embedded in the images. This means that images are always displayed in the working color profile (usually sRGB). If the images were taken in a different color profile they will be shown with incorrect brightness or color.

However the operations performed by PTGui (stitching and blending) are color neutral; therefore the output panorama will be in the same color space and the final result is not affected.

For regular (non HDR) panoramas the output file is tagged with the source ICC profile, provided that all source images have the same color space. The output from tone mapping and exposure fusion (for HDR panoramas) is currently not tagged with an ICC profile; such files need to be tagged manually with the ICC profile of the source images. To do so, open the tone mapped or exposure fused panorama in Photoshop, choose Edit-Assign Profile and pick the profile of the source images from the list.

The same applies to panoramas converted to QTVR, cubic and the Publish to Website tool. When publishing panoramas to the web it is recommended to convert the images to sRGB profile. This ensures that the panoramas are shown correctly in all browsers and plugins, whether color managed or not.

Improved color management is one of the planned features for a future version of PTGui. When you press Align Images, PTGui analyzes your source images and looks for details which can be seen in multiple images. For example, the corner of a building might be visible in the right hand side of one image and in the left hand side of another image. On these matching details PTGui places so called Control Points. To see what control points look like, go to the Control Points tab in PTGui after you have run Align Images. In the Control Poins tab select two overlapping images by clicking the numbered tabs above the images and you will see numbered markers indicating the matching features. Ultimately the control points are used by PTGui to set up the panorama: it warps and moves the images in such a way that the control points match as closely as possible.

If you see the above message, this means that PTGui was not able to find control points for all images. The human eye is still better in recognizing patterns than a computer and in this case you will need to help PTGui a bit. To do so, first open the Control Point Assistant (in the Tools menu). The Control Point Assistant will tell you what the problem is, for example 'Image 4 does not have any control points'.

Besides single images lacking control points it's also possible that there are clusters of images linked by control points: for example image 1,2 and 3 are linked by control points and image 4,5 and 6 are linked by control points, but there are no control points between images in either cluster. To create a panorama all images should directly or indirectly be linked by control points, so in this example adding control points between image 3 and 4 would solve the problem.

Suppose the Control Point assistant tells you that image 4 does not have control points: go to the Control Points tab in the main window, and choose image 4 in the left pane. In the right pane find an image which partially overlaps image 4 (most likely image 3 or image 5). Find an object which is visible in both images, click on that object in the left image and click on the same object in the right hand image. As you see a colored marker has been added. Repeat this until you have added at least 3 control points. Then go back to the Control Point Assistant and see if there are any other images that need control points.

When done, go back to the Project Assistant tab in the main window: the above error message is now gone. As the last step the project needs to be optimized: click on the blue underlined link to do this. The optimizer will re-align the images such that the control points match as closely as possible. Verify the result in the Panorama Editor window: the panorama should now be set up properly.

The above workflow is shown in detail in our Video Tutorial.

Sometimes an image contains no recognizable details at all (for example if the images contains pure blue sky only). In that case see Q5.30.

For more information use the on line help available for the Control Points tab and the Control Point Assistant window: in most screens you can get context help by pressing F1 (Windows) or Fn+F1 (Mac). The orientation of the images the main window is synchronized with the orientation of the images in the stitched panorama. For example, if you rotate an image in the Panorama Editor 90 degrees clockwise, the image thumbnail in the Project Assistant will be rotated clockwise as well. And if you rotate the entire panorama 90 degrees, all images in the Project Assistant will be rotated too.

If PTGui seems to randomly rotate your images after running Align Images, most likely it was unable to properly align the panorama, resulting in misaligned and randomly rotated images in the Panorama Editor. It may seem that the misalignments are caused by the random rotation but it is in fact the other way round: due to the misalignments the images get randomly rotated in the panorama, and the orientation of the images in the Project Assistant simply reflect the orientation of the images in the panorama.

In most cases the problem is caused by control points between unrelated images, causing severe misalignments in the panorama. See Q3.1 for details. First of all, if you are new to PTGui check out our Video Tutorial. It may help you understand what the problem might be. In particular make sure that all images are taken from exactly the same viewpoint and that the camera is rotated around the entrance pupil of the lens (which is usually close to the front of the lens). In general a regular tripod is not suitable for taking panoramas; you need a dedicated panoramic head to ensure that the camera is rotated around the front of the lens and not around the tripod screw.

If this does not solve the issue please post your panorama to the PTGui support forum and we'll be happy to take a look. Files cannot be uploaded to the forum directly; instead create a zip file with your panorama and upload it to a file publishing site such as ge.tt. Then include the URL of the uploaded file in your forum post. To allow us to help you quickly, upload at least the PTGui project file (.pts). Depending on the problem we may need the image files as well. Regularly when we release a new version, the installer is diagnosed with the WS.Reputation.1 threat and blocked by Norton Antivirus.

According to Symantec WS.Reputation.1 means that the file has a low reputation score: 'The reputation-based system uses "the wisdom of crowds" (Symantec’s tens of millions of end users) connected to cloud-based intelligence to compute a reputation score for an application, and in the process identify malicious software in an entirely new way beyond traditional signatures and behavior-based detection techniques'.

In other words: PTGui was blocked just because it has had relatively few downloads among Norton Antivirus users. Which makes sense because it is a new version...

Now Symantec does offer software vendors the option to submit their software to have it whitelisted. When we do so we get a friendly reply: 'Thank you for your request [...] For a Software White-list request, Symantec will target a response of advising you of our final determination within 3 weeks.'.

To install PTGui you may therefore need to temporarily disable Norton Antivirus while downloading and installing. For more information see How to bypass Symantec’s WS.Reputation.1 System. But we recommend to switch to a different virus scanner altogether. The next time Norton nags about your expired subscription, consider switching for example to Microsoft's own free virus scanner: Microsoft Security Essentials.

If you are still unsure whether it's safe to install PTGui, upload the installer to virustotal.com and have it scanned by over 40 different virus scanners. This problem can be resolved as follows: After rebooting, verify the change by launching PTGui and going to Help - System Information

At the line 'Max number of files: current:' you should now see a number somewhere in the 65000 range.
4. Improving the results

See Tutorial: straightening a panorama First of all always make sure to lock the exposure and white balance of your camera. Color differences can be corrected to a certain amount by the blending process, but you will get the best results by locking the color balance and exposure when shooting the images.

Exposure is locked by choosing the M mode if your camera. To lock white balance, choose one of the white balance presets on your camera that match the current lighting, such as 'Cloudy' or 'Sunny'.

Even with color balance and exposure locked you may still see get small differences in brightness due to vignetting. PTGui Pro can correct for this, see Vignetting correction with PTGui Pro. This can be done in the Create Panorama tab, Advanced section. Switch PTGui to Advanced mode to make this section visible.

Be aware though that the resolution of an image has nothing to do with image quality, or print quality. The ppi/dpi value of an image file is just a number embedded in the header of the file, suggesting the number of pixels to be printed in one inch. The number of pixels is what really matters: if you need a more detailed output image, increase the width and height of the output image instead (on the Create Panorama tab). Click the 'Set optimum size' button in PTGui and choose 'Maximum size' to achieve the highest quality. Increasing the output size beyond the optimum size is possible but will only increase the file size, not the amount of visible detail, since the latter is limited by the (angular) resolution of the source images.

See also: The Myth of DPI. Parallax: First of all, make sure that the photographs are taken properly: for panoramas, all images should be taken from exactly the same viewpoint. More in particular: the camera should be rotated around the 'no parallax point' (sometimes referred to as the 'nodal point') of the lens. For most lenses this point is located near the front element; since it does not coincide with the tripod screw of the camera, you will need to use a so called panorama head on top of your tripod if accuracy is important. If the camera is not rotated exactly around this point, parallax errors will occur, preventing a perfect stitch.

In about 4 out of 5 support questions we receive regarding stitching problems, parallax turns out to be the reason for the problem. Therefore for an introduction to parallax please read these articles: Finding the no-parallax point (by John Houghton) or What is parallax? (PanoGuide). Be sure to also watch our Video Tutorial: parallax is explained in the first video.

The impact of parallax errors differs per scene: for a landscape panorama, with no objects close to the camera, a limited amount of parallax is usually not a problem and such a panorama can easily be taken handheld. But for panoramas of room interiors even a small misplacement of the camera of just one centimeter or inch will result in clearly visible stitching faults. Creating a good interior panorama is therefore impossible without using a tripod and properly calibrated panoramic head.

In contrast to (e.g.) barrel distortion, correcting for parallax faults in software is impossible. This is not a limitation of PTGui but a physical limitation. If you must stitch images with parallax, the best you can do is to mask the faults after stitching by placing the seams appropriately (see our post processing tutorial) but this can be a lot of work and often does not lead to perfect results. Parallax problems lead to overall high control point distances: if you have many control points with an optimized distance of 20 or more (see below), this usually indicates a parallax problem.

Misplaced control points can be another reason for misalignment. Especially if there are repeating structures in the images, the control point generator may occasionally misplace one or two control points. The same can happen if there are moving objects in the panorama: slowly moving clouds in the sky are notorious in particular. Finding these misplaced control points is easy: open the Control Point table (Ctrl+B on Windows or Cmd+B on Mac) and find the control points with the largest distance. This distance indicates the alignment error of the control point in the panorama. By default, the table is sorted in descending distance, so the worst aligned control points are in the top of the list. In general, a distance below 5 is sufficient, while higher values usually indicate a problem. Double click on a control point in the table to edit it, or delete it by pressing Del.

Misalignment in an area of a panorama can occur if there are no control points in that particular area. Go to the Control Points tab and add a few points in problem areas to improve the alignment there.

A common misconception is that using a wide angle lens would cause misalignments, due to the distortion inherent to wide lenses. This is not true: PTGui can perfectly correct perspective distortion and barrel distortion in wide angle lenses. A panorama from a wide angle lens will thus look exactly the same as the same scene taken with a long lens, apart from any differences in quality and resolution.

Lens shift: Another reason for stitching errors can be a misalignment of the center of the lens to the center of the image sensor in the camera: Ideally, the lens axis should be perpendicular to the sensor plane and point towards the center of the sensor, but in most cameras there is a small offset. By default, the warping and lens correction in PTGui is performed relative to the center of the image. This will result in less accurate image transformation when the lens is mounted off center. PTGui can correct for this using the 'shift parameters' (also called d and e), as follows: This will shift the source images in such a way that the best optimization is achieved. However, we have not enabled the shift optimization in PTGui by default, since it may give unexpected results if the control points are not distributed evenly across an image. For example, if all control points are located in the bottom half of the panorama (which often is the case if the upper part consists of blue sky), the whole panorama may shift as a result. So it is important that the control points are distributed over the entire image for this optimization to work. Also, shift optimization often fails if there are parallax errors. If it doesn't work as expected, press Undo (Ctrl-Z) repeatedly until the project is restored to its original state. No, not necessarily. When editing control points you should not just aim for the lowest possible control point error. Instead the goal should be to keep all control points that are placed correctly, and delete only the faulty ones. Faulty control points include for example points placed on moving objects such as people, clouds and cars, and control points placed incorrectly on different objects. The latter may happen in particular with repeating structures.

Often these misplaced control points have a higher than average control point error, but the reverse is not true: not every control point with high error is a faulty one. If you have a control point pair with a large error but with both markers placed on the same spot on a non-moving part of the panorama, then this control point actually improves the alignment of that particular area in the panorama. Therefore it should be kept rather than deleted, even though this increases the average control point distance.

If you are consistenly getting control points with high errors (say, 5 or higher) then this most likely means that your images suffer from parallax. Only images without parallax can be stitched perfectly. See Q4.4 for more about parallax.
5. How to...

You would need to use the rectilinear panorama projection. Rectilinear projection is the only projection that preserves all straight lines; all other projections will curve certain lines. Unfortunately rectilinear projection is limited in practise to a maximum field of view of about 120 degrees, so there is no way to preserve straight lines for wide panoramic scenes. This is not a limitation in PTGui but a physical limitation.

For more information see: Projections To create a QTVR movie, choose 'QTVR' as the file format. The panorama projection should be set to equirectangular, 360 x 180 degrees. This can be done by choosing 'Spherical' in the Panorama Editor Menu / Projections. The result is a cubic .mov file, which can be viewed in the QuickTime Player, or embedded in a web page. John Houghton wrote an excellent tutorial about this.
German readers see this page by Bernhard Vogl For panoramic stitching you don't need to know the lens parameters since PTGui calibrates your lens automatically for each panorama. But knowing the lens parameters can be useful if you (for example) would like to correct a single image for barrel distortion. The lens parameters can be calibrated accurately as follows:
  1. Take enough images to build a 360 degree, single row panorama. Make sure the images overlap by at least 30%. Make sure that the camera is rotated around the 'no parallax point' of the lens, in order to avoid parallax errors.
  2. Load the images into PTGui, and execute step 2 (Align Images) of the Project Assistant.
  3. Switch to the Control Points tab and review all generated control points. Remove any misplaced control points, and any control points on moving objects (including clouds in the sky!). Also remove any control points on nearby objects, since these will suffer the most from any remaining parallax errors in your setup. Make sure that each pair of overlapping images has at least 4 control points (more is better). Ensure that there are some control points in the corners of the images as well, not just in the center.
  4. Optimize the project using the Optimize button in the Project Assistant.
  5. Open the Control Point table (Ctrl+B or Cmd+B). The control point distances should be small, generally less than 3. If you find control points with higher distances, correct or remove them by repeating the previous two steps.
  6. Switch to Advanced mode by pressing the Advanced button in the Project Assistant.
Now the optimized lens parameters can be found as the a, b and c parameters on the Lens Settings tab. Use the Lens Database button to save the values for later use.

Please note that different orientations (landscape vs. portrait) and different focal lengths (in case of zoom lenses) will result in different correction values, so be sure to save separate entries in the lens database for each zoom setting and for landscape and portrait orientation. Even at the same zoom setting and orientation subsequent calibrations may result in significantly different a/b/c values. This is normal, since completely different a/b/c values may represent very similar lens correction curves. In general this is not possible. PTGui was designed for stitching true panoramas, by taking overlapping photos from a single camera viewpoint. If the camera is moved between shots, parallax errors will occur. Correcting for parallax errors in software is physically impossible so in general it is impossible to stitch such images without visible misalignments.

There is one exception: if the subject to be photographed is flat, like a wall or like aerial photographs (shot from some altitude and without high rise buildings), parallax faults will not be noticable. Such images can be stitched in PTGui if the following conditions are met: Under these circumstances the photos can be stitched using the process for stitching mosaics, see the section directly below.

If the subject to be photographed is not too wide and the camera can be placed at sufficient distance, consider taking your photographs as a true panorama instead, from a single camera viewpoint. Choose a rectilinear panorama projection so that straight lines in the scene will remain straight in the panorama. The result will probably look better than when attempting to stitch images where the camera was moved between shots. PTGui was designed for stitching panoramas, from photographs taken from a single camera viewpoint. When stitching a panorama, images are warped to correct for perspective distortion so that a seamless overlap is achieved. For mosaic-style stitching on the other hand the images should only be shifted and rotated; any perspective warping is undesirable. PTGui can be tricked to do no warping by setting the field of view of the source images to a very small value, which corresponds to a tele lens with a long focal length.

To stitch mosaics, proceed as follows: Your mosaic is now ready to be stitched at the Create Panorama tab. Yes, this is possible. Although the field of view sliders in the panorama editor always crop the panorama in a symmetrical way (keeping the horizon of the panorama in the middle), an alternative way to crop the panorama is by using the yellow crop lines which can be dragged from the corner of the image in the panorama editor. An example of this is shown on page 4 of the Quick Tour. The crop lines can be placed anywhere so this method is not restricted to symmetrical cropping. The easiest way to achieve this is by using the Masking features in PTGui Pro. See the tutorial: Masking in PTGui Pro.

If you don't have the Pro version a similar result can be achieved with some more effort by adding an alpha channel to the source images and making unwanted parts in an image editing program (such as Photoshop) before loading the images in PTGui.

Finally you can also retouch a panorama in Photoshop after stitching, by using a layered output format; see the Post processing tutorial. For single row panoramas, PTGui will always attempt to align the images in a horizontal row. This behaviour cannot be changed, but you can easily rotate the panorama: in the Panorama Editor, simply use the right mouse button and drag the panorama to the right orientation. After rotating, you may need to press 'Fit Panorama' in the Panorama Editor to resize the panorama area so that it fits.

Vertical panoramas usually look best in one of the Transverse projections. You can choose a suitable projection in the Projection submenu of the Panorama Editor menu. There are several options. Peter Nyfeler has created a Photoshop action for adding a mirror ball nadir cap.

Or you could use your own logo. The logo needs to be warped into the projection of the panorama, as follows: The result is a warped version of your logo. Overlaying the logo has to be done manually in a graphics editing program. A quick way to do this in Photoshop is by selecting the entire logo image (Ctrl-A), copying it (Ctrl-C) and then pasting it into the panoramic image (Ctrl-V). This creates a new layer in the panorama with the logo.

If you have PTGui Pro, instead of covering the missing parts consider using Viewpoint Correction to create a full panorama of the entire scene including the nadir. See the Viewpoint correction tutorial. Choose 'Make Default' in the file menu to save the current settings as a starting point for new projects. This will save all settings, except for the images and control points. It works exacly like Apply Template but it is applied to every new project.

Even if you changed the defaults, the Project Assistant will still override certain settings in order to ensure a good result: it will adjust the field of view of the panorama to fit the contents, it will choose a suitable projection depending on the field of view, and it will choose an appropriate output size. All of this can be disabled in the Project Settings tab, section 'Align Images behaviour' (PTGui Pro only). If you want to output panoramas at a predefined size and projection, disable the 'fit panorama', 'choose a suitable projection' and 'set output to the maximum size' checkboxes. Be sure to select 'Stitch using: PTGui' on the Panorama Settings tab.

The maximum output size in PTGui depends on the file format: Clearly, the .psb format is the choice for large panoramas, but unfortunately this format is not widely supported (you need Photoshop CS or later).

Predicting the file size of a TIFF or .psd file is difficult, since this depends on the degree of compression that can be achieved. For large panoramas, you may find that the resulting file is larger than the 2 GB or 4 GB maximum and cannot be opened. You can keep TIFF files generated by PTGui as small as possible by choosing 8 bit output, LZW compression and 'no alpha channel' at the file format settings in the Create Panorama tab. This can be done using PTGui; it can be used for (e.g.) accurately aligning a set of images for manual HDR creation, for making a time lapse movie, or for extending depth of field by merging images taken at different focusing distance.

It requires a special workflow though. By default, PTGui expects that a project contains overlapping source images, taken from the same viewpoint, but in different directions. The perspective changes that occur when the camera is rotated allow PTGui to accurately calculate the focal length (or field of view) of the lens. When all images are taken in the same direction, this information is missing and PTGui may end up optimizing the lens parameters to wrong values. This can result in a very small field of view, or introduce barrel distortion.

If the images are taken in one direction, they can be aligned in the following way:
  1. Load the source images in PTGui.
  2. Switch to Advanced mode by pressing the Advanced button in the Project Assistant.
  3. Go to Lens Settings and make sure that the correct focal length for your lens is configured. In most cases PTGui will have been able to determine this automatically, based on the EXIF data of your images. While you are here, also ensure that the a, b and c parameters are set to 0.
  4. Go to the Optimizer tab, uncheck 'Optimize lens Field of View' and choose 'Minimize lens distortion: No'.
  5. In the menu bar, choose Control Points|Generate Control Points.
  6. Press F5 to launch the optimizer. The images are now aligned properly.
  7. In the Panorama Editor window, press the Fit Panorama button. Optionally adjust the field of view using the two sliders if you need to adjust the cropping of the output.
This can be useful for creating HDR panoramas, where the bracketed exposures have been taken in identical orientations, or for stitching panoramas that were taken with an exactly reproducible setup (using a panorama head with accurate click stops).

To stitch multiple panoramas with the same settings, the Apply Template function can be used (also see Q2.13). Create the first panorama in the regular way and save the project file. For the subsequent panoramas do the following: By default PTGui assumes all images have been taken with the same lens. It is possible to use multiple lenses by manually overriding some settings: Note that the control point generator assumes that all images were taken with the same lens, hence it will fail to find control points for images having individual lens settings. You will need to add control points by hand for those images. The Control Point Assistant window will tell you which images need control points. Once the project contains sufficient control points, press F5 to run the Optimizer. To do this, you first need to get the calibrated parameters of your lens, as described in Q5.4. Save the calibrated values to the lens database in PTGui.

To correct a single image: After the above steps, the project can be saved as a template. For subsequent images, start a new project, load the image to be corrected, choose File | Apply Template, and pick the template project.

Since lenses are characterized in PTGui by their horizontal field of view, separate calibrations are required for landscape and portrait images. PTGui comes with a web panorama viewer and authoring tool. With a few clicks you can create the files needed to show your panorama on a website.

First stitch your panorama to a flat image in JPEG or TIFF format. It's best to use Equirectangular projection (click the Equirectangular button in the Panorama Editor). Make a note of the horizontal field of view of the panorama, this is shown in the status bar of the panorama editor window.

Then go to Tools -> Publish to Website to open the authoring tool. For more information about the different settings see the accompanying Help page. Press Convert to process the panorama. This creates a HTML page and 17 other files; all files should be uploaded to a folder on your web server. Then link to the HTML page to show the panorama.

The PTGui panorama viewer automatically choses between 3 different technologies (Flash, CSS3D and WebGL) to display the panorama. This ensures that your panorama is viewable in most web browsers, including the iPad and iPhone. It is however intended to be a simple and quick way to show your panoramas on a website. If you need more advanced features such as hotspots, custom buttons, etc, several other free and commercial Flash panorama viewers are available: To produce a virtual tour for iPad/iPhone/iPod you can use: Finally, panoramas can be displayed in Java using PTViewer. Extremely large panoramas (up to several gigapixels) can be shown in a website using Zoomify. A panorama is first cut into small tiles using the Zoomifyer application. This application can be downloaded from the Zoomify website, or you can use the Zoomify export built into recent versions of Adobe Photoshop. The Zoomify player is a Flash plugin, enabling zooming into the panorama at the full resolution. The PTGui Gallery includes several examples. Besides straightening a panorama manually in the Panorama Editor, it's also possible to level a panorama using 'horizontal line' and 'vertical line' control points. Such control points indicate points that should end up on a horizontal or a vertical line in the panorama. PTGui is able to modify the orientation of the panorama in such a way that the horizontal / vertical line control points are aligned on a horizontal or vertical line, respectively, in the panorama.

Vertical line control points can be placed on any vertical feature in the panorama, such as the side of a building. Horizontal line control points should only be placed on the horizon itself: in a spherical panorama, all horizontal lines are curved, except for the horizon itself. For most panoramas (in particular cityscapes) it's easiest to use only vertical line control points. One exception would be a panorama of a sea shore: here you could place horizontal line control points on the horizon.

To add horizontal / vertical line control points, switch PTGui to Advanced mode by pressing the Advanced button in the Project Assistant. While regular control points can only be placed between two different images, horizontal / vertical line control points can be placed within the same image. To do so, choose the same image in the left and the right pane in the Control Points tab. The 'CP type' listbox sets the type of control point that will be created next. Choose 'horizontal line' or 'vertical line'. Then click on two points (one in the left pane and one in the right pane) that should be aligned horizontally or vertically. Even if the two points are within the same image, place one point in the left pane and one point in the right pane.

For most panoramas it's sufficient to place two pairs of horizontal line or vertical line control points, although it will not hurt to add more. The best results are achieved if the two pairs are in different parts of the panorama, preferably in a 90 degree yaw interval (e.g. one in northern direction and one in eastern direction).

Now there are two ways to have PTGui align the panorama based on the horizontal / vertical line control points:
  1. In the Panorama Editor menu bar, choose Edit | Level Panorama.

    PTGui will rotate and move the panorama in such a way that the horizontal / vertical line control points are aligned as much as possible. This is similar to dragging the panorama in the Panorama Editor in 'Panorama Edit' mode: since the panorama is moved as a whole, the alignment of individual images is not affected. Or:
     
  2. Use the optimizer by pressing the 'Optimizer' or 'Run optimizer' buttons.

    If the optimizer tab is in Simple mode (this is the default setting), or if in Advanced mode with 'Level in second pass' selected: PTGui will do a two stage optimization. First the images are aligned as usual based on the normal control points. The horizontal / vertical line control points are ignored in this step. In the second pass the optimizer levels the panorama as described above, using only the horizontal / vertical line control points. In other words, horizontal / vertical line control points are only used for levelling, and only the regular control points are used for aligning the images.

    If the optimizer tab is set to Advanced mode and 'Include in single pass' is selected, everything is optimized in one pass. Now the horizontal / vertical line control points will be used to optimize image alignment too. This can be useful in particular for straightening a single image based on horizontal and vertical features, but is not recommended for leveling panoramas. When 'Include in single pass' is selected, it is necessary to give the optimizer sufficient freedom by allowing it to modify the pitch and roll of all images (i.e. the pitch and roll checkboxes for all images should be checked). With 'Level in second pass', or with the optimizer in Simple mode this is not needed.
Also see the following tutorials:
How to level a panorama in PTGui (video tutorial by Hans Nyberg)
Vertical Alignment of Panoramas with PTGui (by Willy Kaemena)
Levelling an already stitched panorama (video tutorial by John Houghton)
First you need to determine the vignetting of your lens. To do so, take a small panorama (e.g. 3 images, each overlapping about 50%). The amount of vignetting depends on the aperture of the lens so this should be done for each aperture at which you intend to do vignetting correction. In this calibration project, go to the HDR/Exposure tab and press Optimize Now. Press the Save buttons below the vignetting curve and the camera response curve to save the curves to a file.

The actual vignetting correction can be done as follows: You can save the thus created project to a file and use it as a template for subsequent corrections: you will only need to start a new project, load the next source image and choose Apply Template.

It's possible to combine this process with barrel distortion correction, see Q5.16. It's often difficult to retouch the nadir and zenith of a panorama, due to the stretching that occurs at the bottom and top of the image. A solution is to reproject the panorama such that the nadir or zenith is in the middle: After retouching the nadir in the reprojected panorama, use the same process, but now with a pitch correction of +90 to reproject it back to the original orientation. Instead of creating a QTVR directly in PTGui, create the panorama in equirectangular format first. In the Create Panorama tab, choose 'File Format: Photoshop' and 'Layers: Blended and Layers'. The resuting file can be edited in Photoshop as described in the Post processing tutorial. When you are done editing, choose 'Flatten Image' in the drop down menu in the Layers palette in Photoshop and save the panorama in TIFF or JPEG format. Launch PTGui again and choose 'Tools - Convert to QTVR / cubic' to convert the panorama to QuickTime VR. PTGui does not require your photos to be limited to a single row. To fill the missing parts just take additional pictures with the camera pointing upwards ('zenith') and downwards ('nadir') photos. As always you should make sure to rotate the camera around the 'no parallax point' (see Q4.4). This is even more important when shooting the nadir and zenith photos.

Start a new PTGui project and load all your images, including the nadir and zenith photos, before pressing Align Images. The order of the photos is not important, PTGui should be able to figure out which image belongs where in the panorama.

Sometimes PTGui is unable to find control points, and this may happen in particular with nadir and zenith images (for example if the zenith image contains mostly blue sky). In that case you will see a warning 'PTGui was unable to find control points for one or more images' in the Project Assistant. If this happens see Q3.14. If you did not include a zenith and nadir image (with the camera pointed upwards and downwards, respectively) the top and bottom of the spherical panorama are not covered by images, resulting in black circular holes at the top and bottom. To hide these holes you can limit the vertical viewing angle by setting a minimum and maximum tilt angle in the Publish to Website window.

This will limit the amount in which the viewer can look up and down so that the black borders remain unvisible. Cropping can be done in two ways: This can be done in the Project Settings tab (PTGui Pro only):

Disable the checkboxes 'Fit panorama', 'Choose a suitable projection' and 'Set output to the maximum size (...)'. Then choose the desired projection and field of view in the Panorama Editor, and set the desired output size in the Create Panorama tab.

These settings can be re-used by saving this as a template using File -> Save As Template. A fisheye lens distorts images such that straight lines become curved. Removing this distortion is typically called 'defishing'. Please note that it is not necessary to defish images prior to stitching, PTGui can perfectly handle fisheye source images.

Defishing is done by converting from fisheye projection to rectilinear ('flat') projection. A single image can be defished in PTGui as follows: Please note that it's typically impossible to keep the entire image. Fisheye lenses usually have a field of view of 180 degrees while rectilinear projection is limited to around 120 degrees. Attempting to get a wider view will result in extreme stretching of the corners of the image. In fact it is the fisheye distortion which allows a fisheye lens to have its wide field of view. This is done by converting the panorama to rectilinear projection. The process is nearly identical to defishing (see previous question) and the same limitations apply.

Assuming your panorama is a 360 x 180 degree equirectangular image, proceed as follows: Again, flat projections are limited to about 120 degrees field of view; it's impossible to display an entire 360 degree panorama in rectilinear projection. By default, for spherical panoramas PTGui will pick a random point on the horizon as the center point. If the first image of all your panoramas was taken in exactly the same direction, you can use the following method: Now the panorama is aligned around the same point in the first image.

Or, if all panoramas were taken from the same viewpoint but not exactly in the same direction: First stitch the first panorama in the normal way. Create a medium sized copy of the panorama in jpeg or tiff format, we will use this to align the subsequent panoramas against. For each subsequent panorama: Sometimes one or more images in a panorama don't show any suitable objects to place control points on, for example when an image contains only blue sky or a plain white wall. Since the exact alignment of a plain colored image is usually not critical, you can align it by hand:

First make sure that the rest of the panorama is set up properly (usually just pressing Align Images is enough). Then go to the Panorama Editor window by pressing Ctrl+E (Windows) or Command+E (Mac). Switch the panorama editor to 'Edit Individual Images' mode using the toolbar, the menu or by pressing Ctrl+Shift+I (Windows) or Command+Shift+I (Mac). In this mode you can move individual images around. Use the left mouse button to move an image, or use the right mouse button to rotate it. Single button Mac users can use Ctrl+Mouse button to rotate. For more information see the Help page for the panorama editor pressing F1 (Windows) or Fn+F1 (Mac).

When done, go back to the main window, click on Optimize and proceed to Create Panorama. You can ignore warnings about missing control points. To view a spherical panorama interactively (i.e. with the ability to 'look around' by clicking and dragging the mouse) you need a panorama viewer. A selection of panorama viewers: For more viewers see Panorama Viewers (PanoTools.org Wiki).

For interactive viewing the panorama should be stitched as a 360x180 degree equirectangular image. To choose this format select Projection - Spherical in the Panorama Editor menu bar in PTGui. Apple's QuickTime needs a QTVR .mov file; select 'File Format: QuickTime VR' in the Create Panorama tab. The other viewers take a regular jpeg image (in 360x180 degree equirectangular projection), so choose 'File Format: JPEG'.

PTGui can be configured to launch one of these viewers when the Preview button (in the Preview tab) is clicked. To configure this go to Tools-Options (Windows) or PTGui-Preferences (Mac). In the Viewer tab enter the path to the viewer application. A different viewer can be configured for the 3 commonly used projections. No, unfortunately no such format exists, you need to install a panorama viewer to be able to interactively view a panorama. See Q5.31.

Alternatively publish the panorama to your website, on most computers it will be possible to view the panorama without needing to install anything. See Q5.17. We can align an image to a panorama by loading both images as source images in a new PTGui project. By default PTGui assumes that all images in a project have been taken with the same camera/lens, so the key here is to use 'individual parameters' for one of the images. Also the optimizer should be told not to touch the panorama image and only modify the alignment of the overlay image.

To start, you need to know the field of view and the projection of the stitched panorama. This information is visible in the bottom status bar of the panorama editor in PTGui. For a spherical panorama this would often be equirectangular, 360 degrees.

Then proceed as follows: Keep in mind that as with any panorama, parallax errors will prevent proper stitching. Therefore the image to be overlaid should be taken from exactly the same location as the original photos for the panorama.

If you need to do the same for multiple panoramas or overlay images, you can save some time by using templates. Use File - Save As Template to save the settings of the project to a template, and use File - Apply Template to apply the settings to a future project. Control points still need to be placed by hand though since they are specific to the images used. This is done by passing the '-batch' flag and a project file on the command line.

On Windows:
"C:\Program Files\PTGui\ptgui.exe" -batch <projectfile.pts>

On Mac:
"/Applications/PTGui Pro/Contents/MacOS/PTGui Pro" -batch <projectfile.pts>

This will launch the batch stitcher, which will begin stitching the specified project. If configured, in the Pro version only, the batch stitcher can also align the images and generate control points. To do so enable 'Align images and save the modified project' at 'Batch Stitcher actions' in the Project Settings tab. This allows for fully automated batch stitching of images without user interaction. Yes this is possible. The trick is to simulate using a long (narrow angle) lens, in this case hardly any warping will be done. Also, PTGui needs to be told not to optimize the lens field of view or lens distortion. To get an unblended collage you need to choose layered Photoshop output and flatten the panorama in Photoshop.

In short:
If you have your own web server you can use the Publish to Website tool in PTGui (see Q5.17) and upload the results to your website. The panorama will be viewable on Apple iOS devices.

If you don't have a web server or if you would like to be able to view your panoramas without an internet connection, we are aware of two apps that support offline viewing of spherical panoramas: iPano and PangeaVR HD. Both can be purchased in Apple's App Store. Please note that these are third party applications for which we cannot provide support. PTGui currently does not directly support stitching of video footage. But the Batch Builder can be used as a rudimentary tool for stitching video. To do so, the videos first need to be converted into individual JPEG or TIFF frames using a suitable third party video editing application. Stitch the first frame as a regular panorama in PTGui and save the project file. This project file can be used as a template in the batch builder so that all subsequent frames are stitched exactly like the first. The resulting panoramas need to be assembled into a video in a video editing application.

To learn more about the batch builder, choose Tools - Batch Builder in PTGui Pro and press the Help button there.

For a dedicated panoramic video stitcher see VideoStitch. VideoStitch reads PTGui project files and templates; you can set up the stitching in PTGui from video stills, and then stitch the video streams in VideoStitch.

Please understand that perfect stitching is not possible when using multiple cameras. Each camera will have a slighly different viewpoint; the resulting parallax will cause stitching errors. Yes, PTGui Pro includes the Batch Builder for this purpose. The Batch Builder scans a chosen folder for images and creates project files automatically. The project files can be based on a custom template. Once the project files have been generated they can be stitched overnight using the Batch Stitcher. If needed, control points can be generated as part of this process. Or, if the camera positions are known, control point generation can be skipped and all panoramas stitched with exactly the same settings.

For more information, launch PTGui Pro, go to Tools - Batch Builder and click on the Help button. A little planet is a panorama projected such that the floor of the scene is in the center. By using a stereographic projection, the horizon of the scene will become circular, thus giving the impression that the photo was taken from above a small planet.

A the little planet image actually is a fully spherical panorama since it covers both the floor (nadir) and the sky (zenith). Just like a regular spherical panoramas it is most easily taken with a fisheye lens.

To create a little planet panorama load your source images in PTGui and press Align Images. Then go to the Panorama Editor menu and choose Projection -> Little Planet.

Also see: Projections. Currently we do not offer a plugin for Adobe Lightroom, but PTGui can be integrated in Lightroom as an external editor as follows:

Now you can open your photos from Lightroom into PTGui as follows: in Lightroom's library view select the photos to be stitched, right-click (Ctrl+click on Mac) on the selection and choose Edit In - PTGui. Then if you want to stitch the original photos choose Edit Original (note that PTGui will only read and never modify your source images). Or to stitch the photos with any Lightroom adjustments choose Edit a Copy with Lightroom Adjustments.

After the panorama has been stitched in PTGui, go to the folder in Lightroom's library where PTGui has created the panorama, right click on the folder name and choose Synchronize Folder. This imports the stitched panorama back into Lightroom.
6. PTGui Pro and HDR

Disable all automatic features of your camera, except for automatic bracketing. In particular: The 'M' mode is present on every (digital) SLR camera, but most compact cameras lack this mode, which makes them unsuitable for HDR stitching with PTGui Pro. Yes, just enter the exposure data in the Image Parameters tab. At least the exposure time should be filled in for each image; the aperture and iso fields can be left blank. Switch PTGui Pro to Advanced mode to make the Image Parameters tab visible. Most likely your camera was in automatic exposure mode when taking the images.

Please take a look at the actual exposure data (aperture, exposure time, iso) in the Image Parameters tab. Switch PTGui Pro to Advanced mode to make the Image Parameters tab visible.

For HDR, only the exposure time should be varied. The aperture and iso value of all images should be the same. Further, the exposure times of the images should follow a repeating sequence. For example: 1/25, 1/100, 1/400, 1/25, 1/100, 1/400, and so on.

If the exposure times do not follow such a repeating sequence, even though auto bracketing mode was enabled, this can only be caused by the camera being set to an automatic exposure mode. In automatic exposure mode, the camera adjusts the exposure between each set of bracketed images and as a result, the exposure times will be different in each set of bracketed images.

On SLRs, automatic exposure is enabled in the P, Av and Tv modes. Only in the M mode automatic exposure is disabled, hence the M mode is the only mode suitable for photographing HDR panoramas. Most digital compact cameras are not suitable for HDR panoramas due to the lack of a manual exposure mode. Most likely your camera was in automatic exposure mode; see Q6.3.

In general, the this problem is caused by the fact that the images do not cover the full panorama for every exposure time used. For example, if you took images at (e.g.) 1/25, 1/100 and 1/400s, then a full panorama should be taken at each of these three exposure times.

PTGui Pro groups the images by exposure time, and stitches and blends a complete panorama from each group. These blended panoramas are called 'blend planes'. Finally, the blend planes are merged to HDR and optionally tone mapped.

If an image is missing, e.g. you forgot to take one of the 1/100 images, then the resulting blend plane contains a gap. PTGui will attempt to merge the three blend planes into HDR, but the gap causes a hard edge in the result. HDR merging should not be compared with regular panoramic blending: it does not attempt to create a soft transition between overlapping images. Instead it picks the 'best' pixel data from each blend plane.

To verify that at each exposure time a full panorama is covered, enable the 'blend planes' output setting in the Create Panorama tab. Take a look at the resulting files to make sure that each blend planes covers the full panorama. You can trick PTGui into recognizing your images as bracketed exposures by modifying the exposure data in the Image Parameters tab. If you took sets of 3 bracketed exposures, copy the exposure times of the first three images into the remaining images. The result should be a repeating sequence, e.g. 1/25, 1/100, 1/400, 1/25, 1/100, 1/400, and so on. Switch PTGui Pro to Advanced mode to make the Image Parameters tab visible.

However, the result will not be perfect. The automatic exposure has caused brightness differences between neighbouring images. The blender is able to make gradual adjustments, but it does not actually correct the exposure differences. Therefore we recommend to go back and take the bracketed images in manual exposure mode. The nice thing about HDR is that you don't need to worry anymore about proper exposure! By taking bracketed exposures, everything will be exposed properly in at least one of the images (provided the bracketing range is sufficiently wide). During HDR merging, the best part of every image is used in the final merged result. Over and underexposed pixels are discarded automatically. The Exposure Value (EV) recorded in the EXIF data (in the Exif 'exposure bias' field) indicates the difference between the actual exposure and the optimum exposure as measured by the camera's light sensor. In other words, it's the exposure offset the camera was instructed to use. It is not an absolute value and does not tell the actual amount of light captured.

On the other hand, the EV shown in PTGui Pro (Image Parameters tab) is calculated from the actual exposure data (exposure time, aperture and iso). This is the data that is used when generating HDR. The EV is a relative value, which can have an arbitrary offset. PTGui Pro offsets the EV such that the lowest EV equals zero minus the highest EV (i.e.: low = -high).

A difference between the displayed EV and the recorded EV can have two reasons: If you used auto bracketing in auto exposure mode, the camera has likely adjusted the base exposure time between each set of bracketed shots. In that case the bracketed sets themselves have an exposure offset within the panorama. A second reason is the limited choices of exposure times. For a +1 EV offset from 1/15s, most cameras will use 1/8s instead of 1/7.5s. The actual offset in this case is +0.9 EV. PTGui Pro can link images. Linked images have the same yaw, pitch, roll and other parameters. When a parameter of one such image is changed, the same changes are applied to the linked images. The optimizer treats the linked images as a single image and combines all control points of the linked images.

The link status of individual images is shown in the Image Parameters tab (visible in Advanced mode only). When the 'Link' checkbox of a certain image is enabled, the image is linked to the image directly above it. Linking is reciprocal: changes to image A are applied to image B, and changes to B are applied to A.

PTGui Pro can detect bracketed sets of images, and automatically link the images in each bracketed set. This is done by choosing 'Link HDR Bracketed Exposures' in the Images menu. For this to work, the exposure times of the images must follow a strictly repeating sequence, e.g. 1/25, 1/100, 1/400, 1/25, 1/100, 1/400, and so on. In this case, PTGui would recognize the sequence of 3 bracketed exposures each, and link each group of 3 images. If PTGui Pro doesn't recognize your bracketed exposures, the exposure times do not follow such a sequence; see Q6.3 above. If your images were taken from a sturdy tripod, with absolutely no camera movement within each bracketed set, it's best to link the exposures. This way, the bracketed images are guaranteed to be aligned with pixel accuracy. Furthermore it would not be a problem if a certain image is lacking control points, as long as the other images in the bracketed sets are linked by control points.

However, it's not necessary at all to link bracketed images. Linking only locks the image positions, PTGui Pro doesn't need linked images to create HDR. For that it only needs to know the exposure data of each image.

If the images were taken handheld, or if the camera may have moved between shots, the images should not be linked. In this case, PTGui Pro will attempt to align the images using control points. This is possible by creating a layered HDR panorama in PTGui Pro: PTGui will create a layered document with the blended panorama in the bottom layer. On top of that are the individual blend planes. Each blend plane corresponds to the stitched panorama at one exposure level. The blend plane layers have a blend mask which is initally black. By painting with a white brush in the layer mask you can selectively reveal parts of the blend planes.

For details see the Post Processing tutorial. It's not necessary to use external applications since PTGui Pro can create HDR files. But if you prefer to use an external tool for merging to HDR, there are two ways to do this: True HDR file formats (like .exr and .hdr) have a virtually unlimited dynamic range, they don't have a maximum brightness value that can be represented. On the other hand, 8 bit and 16 bit file formats do have a maximum brightness value of 255 and 65535, respectively. Any pixel brighter than this maximum would be clipped to the maximum allowed brightness. Clipped pixels are lost forever, reducing the brightness afterwards would not recover them. To prevent clipping when HDR data is written to 16 bit files, PTGui Pro reduces the brightness of the images such that the brightest pixel in all images does not exceed the maximum value of 65535.

Note that the 16 bit HDR output should be regarded as 'pseudo HDR': it can be used to edit layered HDR files in any 16 bit capable application. But if post processing is done in an HDR capable application, it's better to choose a true 32 bit HDR output format such as .hdr or .exr. For HDR panoramas PTGui currently simply overlays the bracketed images. Therefore only the last image in each bracketed set is visible; the other images are hidden behind. We plan to improve the HDR preview in a future version; in the mean time you can improve the preview by hiding all images except one from each bracketed set. This can be done using the 'EV' selection box at the bottom left corner of the Create Panorama tab (PTGui should be switched to Advanced mode). Choose the EV level that should be previewed and press Select. This will hide all other images in the panorama editor. The images are excluded from stitching as well, so be sure to re-enable them before stitching the panorama. This can be done easily by double clicking on the header above the first checkbox in the 'Include Images' list in the Create Panorama tab. Yes, this is possible. But keep in mind that PTGui was originally designed for creating panoramas and you need to adjust some settings to make this work.

If your images were taken from a tripod and are already aligned perfectly:
  1. Start a new project in PTGui Pro
  2. Click on the Advanced button in the Project Assistant to switch to Advanced mode
  3. Click Load Images and open your set of bracketed images
  4. Go to the Exposure / HDR tab and select 'Enable HDR stitching'
  5. Go to the Panorama Editor by pressing Ctrl+E (or Command+E on Mac)
  6. Choose Edit -> Fit Panorama. On Mac choose Panorama Editor -> Edit -> Fit Panorama. Now the images should fill the entire output area.
  7. Go back to the Exposure / HDR tab. Choose whether you want to use Exposure Fusion or True HDR and adjust the settings. See the online help for more information.
  8. Go to the Create Panorama tab. Choose Set Optimum Size -> Maximum Size
  9. If necessary adjust the output settings in the Create Panorama tab
  10. Finally press Create Panorama to render the output files
If your images were taken handheld they need to be aligned first. Proceed as follows:
  1. Start a new project in PTGui Pro
  2. Click on the Advanced button in the Project Assistant to switch to Advanced mode
  3. Click Load Images and open your set of bracketed images
  4. Choose Control Points -> Generate Control Points
  5. Go to the Optimizer tab. Disable 'Optimize lens Field of View' and select 'Minimize lens distortion: No'
  6. Press the Run Optimizer button at the bottom. This aligns your images.
  7. Proceed with step 4. in the above paragraph
You can save the project as a template using File -> Save as Template. The template can be used again (by choosing File -> Apply Template) for subsequent projects with the same setup (i.e. the same number of brackets, same camera and same lens). If the images are taken handheld, control points need to be generated for each project: repeat the steps 4-7 after the template has been applied. Yes this is possible, but there is no benefit in doing so. The purpose of generating HDR images is to overcome the limited dynamic range of a camera's imaging sensor. Suppose you are photographing a scene with both very dark objects and very bright objects: the dark objects will be close to the sensor's noise level: if you attempt to reveal dark objects by brightening the image in (e.g.) Photoshop, the noise will be amplified too so the dark objects will drown in image noise. Similarly, bright objects may be brighter than the maximum brightness that can be recorded by the sensor and thus completely white (this is called 'clipping'); darkening the photo will not reveal bright clipped objects anymore. To overcome this you take multiple photos of the same scene at different exposure levels. The HDR software (PTGui Pro) will take the 'best' pixels from all photos, i.e. those pixels that are not noisy and not clipped.

It's possible to do 'pseudo HDR' by extracting multiple exposures from a single RAW image, but all exposures will still suffer from the same limited dynamic range of the original RAW image. Hence the brighter exposure will be noisy and the darker exposure will not reveal any detail that was clipped. If you assemble these exposures again into an HDR image you will just end up with an image identical to the original RAW file, only in a different format.

Typically a RAW image has a dynamic range of 12 or 14 bits. No detail will be lost if you convert the RAW image to a 16 bit TIFF file as long as you make sure that no highlights are clipped. I.e. make the TIFF file dark enough until you see as much detail in bright objects as is available in the RAW file. Then stitch those TIFF files in PTGui.

Don't confuse HDR images with tone mapped images: what is typically referred to as the 'HDR look' is actually the result of tone mapping. If this is what you are after just load your original non bracketed images in PTGui Pro, go to the HDR/Exposure tab and select 'enable HDR stitching' and click on Tone Map Settings to preview the tone mapping result. Even Exposure Fusion works with non bracketed images because the algorithm generates artificial extra exposures when you increase the 'Boost Shadows' and 'Reduce Highlights' sliders. When generating HDR images PTGui will look at the exposure settings in the EXIF data of the images to determine which images belong to a bracketed set. Normally the camera sets the proper exposure data in the EXIF header, but when extracting multiple images at different brightness from a single RAW file, all images will still carry the original EXIF data despite the difference in exposure.

To overcome this you need to override the the EXIF exposure data in the Image Parameters tab in PTGui Pro. For example if your original image was taken at a shutter speed of 1/200s but the exposure was boosted by +1EV this effecticely simulates an exposure of 1/100s. EV is a logarithmic scale: +1EV corresponds to a doubling of exposure time; +2EV is a quadrupling of the exposure time, +3EV multiplies the exposure time by 8, and so on.

Once you have entered the artificial exposure times for all images in the Exposure column in the Image Parameters tab, PTGui Pro should recognize your bracketed images if you do Images -> Link HDR Bracketed Exposures.
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