Stitching HDR panos with PTGui

[sanking]

I am interested in stitching some HDR RAW pano files. In reading the features of PTGui professional it appears that it will stitch pano images that are shot in HDR. Has anyone used this feature? I am especially interested in how it returns the final stitched image? Will this be file be in RAW which can then be corrected when opening in Bridge, or is the final file processed in PTGui and returned as a Tiff filel?

Sandy

[Kirk Gittings]

I have a very little experience with it. It is best to do your raw conversions first before importing to the software. IME you get better results that way. It will not output raw.

[Valdecus]

There are various workflows possible for stitching HDR panoramas. The Photomatix FAQ gives you a brief introduction into this:
http://www.hdrsoft.com/support/faq_photomatix.html#panos

No image editing software will return raw files once it has done some processing on them. To be able to process a raw file, it needs to be converted first, and this process cannot be reversed. So, PTGui will output standard JPEG, TIFF, or Photoshop files.

Cheers,
Andreas

[Peter De Smidt]

I recommend optimizing the files in a raw converter. Output those files to a good HDR program, such as Photomatix. Edit the files in your HDR program and output 16 bit-per-channel Tiffs. Stitch the tiffs with a good pano software, such as PTgui or Autopano Giga. Both have free trials.

[sanking]

Thanks for suggestions.

I downloaded a preview version of PTGui and experimented with some HDR pano shots. The software did a pretty good job of merging the HDR shots (with something called exposure fusion, which is described as not true HDR) and then creating the pano. The process was quite time consuming, however, with a MacBook Pro with 8gb of RAM so I don't think this method would be viable when traveling with a Macbook Air and only 2gb of RAM.

Another issue is that the final pano was an 8-bit jpeg (starting with RAW HDR shots), but perhaps this was because of the limitation of the trial version of PTGui.

I am tempted to purchase the software but the professional version is fairly expensive, and it seems that I could do this faster with CS5 by first merging the files to HDR and then running the photomerge command.

Sandy

[Greg Miller]

I am tempted to purchase the software but the professional version is fairly expensive, and it seems that I could do this faster with CS5 by first merging the files to HDR and then running the photomerge command.

Sandy

Yes, this can work well for many images. Just use the same HDR settings for each image stack for the entire series of images, then use Photomerge on the HDR results of each stack.

[Peter De Smidt]

Photomatix, for example, suggests that it's better to do raw processing or noise reduction in a dedicated program, even though P-matix offers those features. They get added because the marketing department feels they need them to stay competitive, but these smaller companies often don't have the resources to produce truly first rate non-core features.

Photoshop can do a bunch of these things quite well, but they have a different character than what can be done in dedicated software. For example, PTgui and Autopano can be successful with panos that completely stump Photomerge in Photoshop, but it only pays to get the dedicated programs if you really need what they can do.

If you have a Windows machine, you should check out Microsoft Ice: http://research.microsoft.com/en-us/um/redmond/groups/ivm/ice/

As an aside, when I do exposure bracketing, I often use a type of exposure fusion over true hdr-tonemapping. Fusion often leads to a much more realistic portrayal.

[D. Bryant]

Sandy,

For HDR (or multi-exposure) stitching I process all of the multi-exposure RAW frames first. Usually this means I adjust the normal or 0 exposure first for CA and lens corrections, and possibly some noise reduction first or upscale the pixel size and then sync all of the frames.

I then process the HDR groups to obtain a blended exposure and save as a single TIFF. I don't normally do edgy tone mapping, rather I just try extend the DR of the image. I then stitch in PS5. The PS5 stitching utility has gotten pretty good but it will still get confused occasionally. After that I will do more work typically in LR and then possibly later again in PS. Needless to say I only do this with 'keepers'. Often I will just perform a quick and dirty stitch of the zero exposure frame to to see how well they will stitch together.

I've easily made 17 x 24 inch prints with a G10 working this way which have MF image quality. I work slowly, use a bubble level and give my images extra space around the frame for later cropping. Over time I've learned to just add more frames to the sequence. Experience helps

For me PTGui's expense isn't worth it, but it maybe a better tool.

If the rules allowed I would post an example here made with the G10.

Don Bryant

[Peter De Smidt]

As an aside, it's not all that hard to put together a nodal slide, or even a 3d panorama head.

[D. Bryant]

As an aside, it's not all that hard to put together a nodal slide, or even a 3d panorama head.

Well I have a Gigapan unit but it sits at home most of the time. Way to bulky to fool with. And all of the other gizmos seem to be expensive too. The RRS pano systems to be very nice but way too expensive. I've tried a friend's RRS pano rig and it too adds bulk and e$pen$e I prefer not to have.

[venchka]

I was going to suggest my $10 solution until you mentioned that you use a MacBook. My software is Windows based.
Workflow:
Canon Raw OR TIFF files from scanner
Lightroom processing
LR/Enfuse exposure and focus stacking
TIFF output
Microsoft ICE stitching & TIFF output
Back to Lightroom for final tweaking

For pure HDR processing, OLONEO Photo Engine worked nicely when I had the early beta/test version. I haven't purchased the commercial product.

Wayne

[Peter De Smidt]

Well I have a Gigapan unit but it sits at home most of the time. Way to bulky to fool with. And all of the other gizmos seem to be expensive too. The RRS pano systems to be very nice but way too expensive. I've tried a friend's RRS pano rig and it too adds bulk and e$pen$e I prefer not to have.

Sorry that I wasn't clearer. I meant that it's not hard to make one. A Nodal slide is super easy to make and not very bulky. A 3d head is also easy to make, but they're quite bulky. Results without pivoting on the entrance pupil of the lens can be very good if there's nothing close to the camera, but if something is close, proper pivoting really helps the results.

[Greg Miller]

I don;t worry about the nodal point very often because pivoting with something very close to the camera mean that "thing" will look very weird anyway. When I do care about the nodal point I just use this plate (http://www.bhphotovideo.com/c/product/303253-REG/Wimberley_M_8_Module_8_M_8_Perpendicular.html)which allows me to vary the position of the camera very easily.

[Paul H]

Autopano Pro handles this quite nicely too, and is a bit cheaper. You can shoot (auto or manual) bracketed exposures, then just point APP at the directory. It will take care of blending and stitching.

IIRC, you can also do the same with Hugin - it requires a little more effort, but the output is similar. Best of all it is free.

[Bill L.]

Thanks for suggestions.

Another issue is that the final pano was an 8-bit jpeg (starting with RAW HDR shots), but perhaps this was because of the limitation of the trial version of PTGui.


Sandy

The full version lets you output 16-bit PSD files. I used to use photomerge, but I've found PTGUI much more flexible and less problematic about distortion for more troublesome images.

Cheers,
Bill

[jb7]

The Pro version of PTGui includes a masking function, which is particularly useful, and worth the upgrade in itself, in my opinion.

I find the Exposure Fusion function to be more predictable, and give more realistic looking output, than the True HDR, which I've never really liked...
Exposure Fusion has more basic tone mapping controls, compared to some of the more esoteric HDR versions, and doesn't challenge you to have to search for the least cartoon-like result.

[sanking]

I have a simple contraption to deal with nodal point. However, doing a HDR bracketed pano shot with PTGui takes a lot of processing time.


Sandy