P: Photo Merge to HDR, dramatic DNG color problem in Lightroom Classic

[Rodeus]

Accidentally faced with color degradation in DNG resulting from Photo Merge to HDR. It looks like a strong decrease in saturation in some tones, as well as the diffusion between different contrasting colors across the color boundary. The algorithm ACR of noise reduction in the color component behaves in a similar way at high values (over 40). But in Lightroom settings I didn't find a way to control the Photo Merge to HDR process. The problem was detected with RAW received from Canon EOS 90D camera in Ligtroom version 8.4 (ACR 11.4) and confirmed in Lightroom 9.3 (ACR 12.3). The DNGs were obtained from 5 exposures (5/3 stops per step). Making a DNG from 3 exposures (also in 5/3 stop, just discarded the most extreme frames), the problem is expressed less, but still there is. Checking on Canon EOS 5Ds and Canon EOS 70D cameras did not confirm the problem. There is nothing wrong with the DNG from RAW on these cameras. Color is deteriorating so badly that I have to look for a solution to save a big and complicated job (I stiched 3 gigapixel panoramas). And I'd already finished the job when I noticed the problem. I had to spend 2 days experimenting and 7 days redoing the whole work. I took the average frames from the exposure bracketing, adjusted them according to the white balance and exposure to DNG, converted to Tiff 8 bit, stiched a new panorama according to the ready stitching project from DNG Tiff's, then put a layer above and restore color degradation according to the Color overlay mode. But there was another problem - partial clipping in lights. I restored them by mask. The final result is here:
https://livepano.l-ark.com/pokrov/giga_final.html

As well as an archive of RAW sets from three cameras (Canon EOS 90D, 70D, 5Ds):
https://fex.net/s/pf2ea9a

DNG vs RAW: https://fex.net/s/vfnkpt9

I have also prepared 2 virtual panoramas that allow you to see the problem clearly, use mouse for navigate (drag to move and roll to zoom or drag and pinch from touch pad):
https://livepano.l-ark.com/pokrov/dng_vs_raw.html

And he recorded a screencast showing how to use these panoramas:
https://recordit.co/N9RS1Er0sC

If it's a bug, can you please tell me if it's enough to tell us about it here? I would like to solve this problem and not to face it anymore. It took too much effort to fix it.

I'm attaching screenshots of the problem:

RackMultipart20200824422561w4b-056061d6-b590-48d3-bd60-00eabd7b4130-1527797288.jpg
RackMultipart20200824127542c85-5100a91d-3bfc-4282-826b-67b5892e88a1-543308223.jpg RackMultipart2020082427742142s-19d22527-0a32-4e07-8409-e1c8a3e2e438-1836694976.jpg RackMultipart2020082483403gguz-9a3c5aa3-b79e-48a4-8f90-0256ddcf1b14-458339568.jpg RackMultipart20200824278265o94-0d18c2c6-0e5e-44ba-b0a3-a37e633af443-1088545528.jpg
RackMultipart202008245784312dm-999a65f8-7a94-4b63-9d32-84cfcc041b95-881422442.jpg RackMultipart2020082427826v32m-6419cdbd-a776-4e78-bd81-9ef0af90f5a5-90672464.jpg RackMultipart20200824112192hcp-7385fd50-a357-42e0-815e-fd1ae0aebd75-1947100936.jpg RackMultipart20200824129311k6s-85f0ff0a-5677-4f9b-93a8-189589b5c181-1095101967.jpg RackMultipart2020082486493wuii-a73e1cad-bc0a-456a-af4e-9280fbb08178-576115835.jpg RackMultipart202008245164811re-cf20c321-3a46-4f57-bcf9-3de858d4206b-887482805.jpg RackMultipart2020082458981r9xv-33c3d2e3-d164-4ac2-8391-3f0171f1b882-71677120.jpg RackMultipart2020082455841jenm-bb2a40c3-7c0b-4f66-9511-546cb6cb4a66-1334941605.jpg

[Colin Southern]

I can't help with the issue you're experiencing, but I did just want to say that that's some stunning architecture that you've photographed there ... and you've done a damn fine job capturing and processing it.

[Rodeus]

Thank you for your kind words, Colin! These gigapanoramas are part of a big job. I shot a few dozen more panoramas of normal resolution and recorded choral singing. The other day we will start programming the virtual tour. All panoramas (in reduced resolution for the draft) can be viewed here. Including the old version of the gigapanoramas, which were unsuccessfully filmed.
https://livepano.l-ark.com/pokrov_temp/

The rest of the panoramas I shot on a full-frame camera and on a fish eye lens.  And there was no problem with the DNG. And for these panoramas, to get more DOF and maximum resolution, I took a 35 Mp camera with a cropped factor of 1.6. And I faced such an unpleasant problem.

This temple is located in Moscow (Russia). And it is comparatively new.

[Colin Southern]

You're doing so well! My "panoramas" are limited to single row, single exposure for art reproduction. You're producing amazing quality here.

[arjunhaarith]

Hi Rodion,

Before I start looking into this issue, I must say that you have done an amazing job. Wonderfully stitched images, and it was so pleasing to see the final result. Fantastic work!!  

For more details on this issue, I will contact you over mail.

Thanks,
Arjun

[Rodeus]

Thank you for the assessment, Arjun! I have 17 years of panoramic stitching experience. And careful stitching does not require any long training. But working with HDR, contrast and natural color reproduction requires continuous skill enhancement. And the fact that LRc has learned how to do HDR DNG in batches has greatly simplified our work with HDR. If LRc had learned how to make auto stacking not only by the time of shooting, but also simply by the sequential analysis of a given number of frames of bracketing exposure, we would live even easier 🙂 But such hurtful misfires with color degradation on the contrary complicate the work.

[Rodeus]

If you deal with parallax-free shooting and the nodal point setting on the panorama head, shooting multi-row panoramas is not much different from shooting single-row panoramas. But to capture gigapixel panoramas, the process becomes a routine that can be transferred to robotic panoramic systems.
Backstage:

[Jerry Syder]

This is amazing!! 

[Colin Southern]

Thanks so much for that - that's a pretty slick looking piece of kit! I do mine the "old fashioned" way by levelling the tripod then levelling the tripod head - manual exposure - check the exposure throughout the arc of what I'm shooting - lock the focus - and then take the shots using the AF marks as a visual guide to getting a good solid overlap. I do a lot of bracketed exposures as part of my normal landscape shooting anyway, but seldon have the need for an HDR composite for stitched panoramas.

You're several leagues ahead of what I'm creating, but here's a link to a typical type of shot (we printed this out on 2 canvas panels each 500mm high and 1600mm wide):

https://pbase.com/cjsouthern/image/160959473/original.jpg

I think it's a "dizzying total" of about 13 shots.

I did buy some software for creating 360 deg panoramas, but haven't found the time to experiment with it much. Seeing your results is definitely inspiring though - I'm not a religious person but I do really admire that kind of architecture; such an incredible amount of detail whilst all fitting together so well with the overal theme.

Gallery of my humble creations here if anyone's interested:  https://pbase.com/cjsouthern/scenery <- shameless plug!

[Rodeus]

You have beautiful works. The nature of New Zealand is beautiful. I thought about visiting New Zealand at one time, but after thinking about everything, I chose India, which is more affordable for my budget. I know a panoramic amateur photographer who lives in New Zealand. But the site where he posted his work no longer works, I can not give a link.

A few other interesting links, if you want. For inspiration, for pumping skills, for communication:

https://www.facebook.com/groups/panoramicphotograph panoramic photographers community (VR360) in FB.

https://roundme.com/explore/editor collection of good works on a popular resource for placing virtual panoramas.

http://www.vatican.va/various/basiliche/san_giovanni/vr_tour/index-en.html virtual tour of Papale Basilica in the Vatican.

http://www.vatican.va/various/cappelle/sistina_vr/index.html gigapixel panorama of Sistine Chapel. For its time (2010) it was very difficult work and very high detail.
https://www1.villanova.edu/villanova/media/pressreleases/2010/0319.html.

https://www.airpano.com/ best panoramas from all over the world. Big work of my good colleagues.

http://www.chem.ox.ac.uk/oxfordtour/default.asp very old work, but still interesting, a tour of Oxford. Probably the first such volume virtual tour, which will soon be 20 years old!

https://naturalhistory.si.edu/visit/virtual-tour very good panoramic pictures of the Smithsonian Museum. Very neat and natural HDR. The main tour was done at a time when LR could not do HDR DNG. And in the interiors without HDR is difficult to do.
https://naturalhistory2.si.edu/vt3/NMNH/z_tour-022.html.

https://thechasepano.com/ Complex and spectacular work
https://vimeo.com/34412004

https://thepanoawards.com/ The Epson International Pano Awards

https://worldwidepanorama.org/ is an interesting project. Since 2004, several times a year the next theme is announced, and photographers send their works on a given theme. During this time a large gallery of interesting works has gathered.

https://www.davidosbornphotography.com/fine-art-photography-for-sale/ British master of panoramic Fine Art.

http://www.rauzier-hyperphoto.com/project-type/creations/ French master of panoramic collage.

https://wiki.panotools.org/Main_Page panoramic Wiki

Unfortunately, many resources are no longer available. The heyday of 360-degree panoramas has passed. Virtual panoramas from a miracle have become commonplace on Google maps. And there were great resources with galleries of the best works of the world, forums, author sites, online industry magazine...

[Colin Southern]

Thanks for all that (and your kind words) - I can see that I'm going to have to make time to get more "into" this.

What focal length are you shooting at for this project?

Many people speak very favourably of New Zealand; having lived here all my life, it's probably true to say that I take it for granted because I've never lived anywhere else. Personally, I see videos from Norway and Iceland than think "wow - there's a place I'd like to visit".

[Rodeus]

I really liked your works. I especially paid attention to BW. You work very bravely with contrast, and it is very tasty. But what is allowed in art photography is not allowed in photorealism. And virtual panoramas, because of their immersiveness, should be as close to realism as possible. Otherwise, the viewer has the illusion that he is in this place right at the moment of viewing. Especially in VR view mode. All my efforts are usually aimed at obtaining a natural picture, with the minimum assumptions I can afford. For example, adjust the white balance a little and the overall feeling of light in the scene. This includes linking scenes shot at different times and under different lighting conditions. When a viewer who has previously watched a virtual tour comes to a real object, he must have the feeling that he was already there. Often, photographers ignore this rule and make a picture or how they do it, due to limited experience, or how they or the customer wants. Brighter, richer, with fantasy colors ("this is how I see the world!"), killing the atmosphere and work of the people who created this room, architects, designers, illuminators. Because the customer pays, and the photographer wants to get paid. The world is cruel ))) I allow myself to warm up the exterior panoramas a little. It is always well received. But these are all certainly the nuances of my taste preferences within the framework that I allow myself. Of course, I can't control which devices the audience will watch my works on. And now the main visual information consumption device is a smartphone. And besides all the variety of color distortions from device to device, people also twist the brightness on their phones, destroying everything that we patiently created, sitting fans in front of expensive monitors ))). The brightness especially changes the perception of panoramas in VR mode. On my VR devices (phone and VR headset) the brightness is usually always very moderate (20-30% of maximum). But even on them, I can feel a difference of about 1/3-2/3 of an exposure step higher when watching in VR mode than just watching from the screen.

My English skills don't allow me to communicate freely on such topics. I use for translation DeepL, the most advanced automated translator available today. I hope that my messages do not lose their meaning.

About focal length. I used Sigma AF 35mm f/1.4 DG HSM Art. Very good lens and a new copy was available for rent. I selected the optics on this service: https://bit.ly/3hxi6WC

If you are interested, I can tell you how we (I did this work with my companion) were preparing for this shooting. I'm still writing all this for myself now for memory and experience for the future. All I have to do now is to translate it all and lay it out. But there will be a lot of text.

[Colin Southern]

Thank you for even more kind words! I completely understand all that you're saying. Although the only rule of landscape photography is "there are no rules", I have to work to much the same standards of realism as you do with product and real estate photography; I'll certainly go to great lengths to ensure that they're lit & presented in the best way possible, but we're not allowed to create anything that's not a faithful reproduction. So I can relate well to what you say.

I was surprised that you shot this @ 35mm; I thought that you'd have needed a much longer focal length to capture that amount of detail when zoomed in - well done!

I would feel like I had unduly burdened you if you were to document how you achieve your amazing results just for me - but if you are doing that anyway then I would certainly read it with interest & appreciation; you're creating extremely high-quality products - and anyone who achieves those kinds of results obviously has a lot of knowledge and skill that would be very valuable if passed on to others.

[Rodeus]

35 mm on the cropped factor 1.6 is already 56 mm in the viewing angle. Plus a 34 megapixel camera. As a result, there are panoramas with dimensions of about 67000x33500 px, which is a little more than 2 gigapixels. Variant 2018 was 45000x22500 (1 gigapixel).

[Colin Southern]

Ah - thanks for that. I'd assumed it would be a full frame camera and a more modest pixel count (I'm still shooting with an 18MP Canon 1Dx and a 21MP Canon 1Ds3).

[Rodeus]

I also prefer a full frame. I shoot regular panoramas with a 15 mm daigonal fisheye lens. But here we had to get enough depth of field, so we took a camera with a cropped factor.

[Todd Shaner]

Arjun Haarith,  a very similar issue was reported at the below link concerning Color Noise Reduction desaturating red objects in both LrC Photomerge to HDR DNG files and Merge to HDR Pro in Photoshop TIFF files.

In April of 2018 I discussed this issue with Jeff Tranberry who forwarded test files to the Adobe  pano/merge engineer Josh. I can confirm the issue is still present today in LrC 9.4, ACR 12.4, and PS 21.2.2.

The only solution I found was to adjust the LR/ACR Detail panel Color Noise Reduction slider to setting of 5 or less, which was sufficient to eliminate color noise. My testing was with the Canon 5D MKII. Please let me know if you need any further information.

https://feedback.photoshop.com/photoshop_family/topics/default-color-noise-reduction-on-merged-hdr-f...