HDR 12-stop merge

DSC01629-small_hdr.exr (23.1 MB)

This file is licensed Creative Commons, By-Attribution, Share-Alike.

Not a RAW, but an HDR created with PTGui out of 5 exposures (-6, -3, 0, +3 and +6 stops). 3 years ago I just gave up with this image. Now I can get something decent out of it. So, for all of you just starting with darktable: there is hope! :upside_down_face:

DSC01629-small_hdr.exr.xmp (9.5 KB)

Curious to see what your take on it is.

J

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Thanks for sharing.

I added the hdr tag for more visibility to those who are interested and have the computing power to handle EXR.

It may be worthwhile to share a single frame for those who have simpler or older machines or prefer simpler processing.

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I would be interested in a single RAW file that captures the external view at its brightest without clipping if that is available. I use to do a lot of HDR when I shot JPGs in the distant past, but now I shoot RAW I usually find HDR process unnecessary except in rare cases.

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Thanks for sharing!
The site https://ptgui.com/ shows impressive panoramas and HDR. On the positive side - it has a Linux version (this is admirable). On the other hand - the price is rather steep. Perhaps if a person shoots extensively panoramas and HDR it would be well worth it but for occasional shooters something like hugin is a very good choice. For clarity - I have been using mostly the panorama part - not HDR.

I’d be curious indeed what a RAW file can achieve. But the picture is quite interesting.


DSC01629-small_hdr.exr.xmp (9,0 KB)

I abstained from trying to show everything what is possible to recover. this simply doesn’t go well with what I’m used to see.
I imagine a scene with quite harsh contrasts, where I’m able to perceive something in the outside. But not with the full range of colour or contrast.

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Decided I’d use CB-RGB to initially squash all the dynamic range, rather than tone equaliser


DSC01629-small_hdr.exr.xmp (16.5 KB)

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GIMP

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Don’t know about that; last time I tried it it segfaulted while stitching. Didn’t bother to investigate (my bad, but there are at least 5 bug reports with segfaults on launchpad). There are “high” importance issues open on Launchpad, opened in 2010. I get the impression that it is not as maintained as it used to be.

DSC01629.-3-0.ARW (46.6 MB)

There you go: -3 stops. The one at 0 stops clips the sky. Likely something in between would have been the best exposure for a single frame, but I don’t have it.

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I like it!

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My compromise.


DSC01629-small_hdr.exr.xmp (9.7 KB)

From the raw:


DSC01629.-3-0.ARW.xmp (17.4 KB)

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My favorite so far (the merged one) – quite realistic, few artifacts, ok colors.

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I can’t help wondering if with such a wide range of exposures there shouldn’t be more detail. I’d love to see what LuminanceHDR would do with the original files.

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I concede that this is a picture that would benefit from a HDR approach but I am unaware of which FOSS software could best handle it. Could you share another raw file with O EV correction. I would be interested in trying to merge just two exposures. In my experience three exposures in the maximum that I found benefited HDR merging. I had previously tried up to nine but settled on three. You could share the +3 EV as well I guess. This would give me and others a chance to do a HDR merge.
DSC01629.-3-0.ARW.xmp (19.7 KB)

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Double exclusioned then some g’mic presets to enhance further. :slight_smile:

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DSC01629-small_hdr.exr.xmp (27.5 KB)

Fun trying to bridge the contrasts, tried to give the walls a glow. Though I realize the interiors to be quite dark in reality. Removed the bluish cast on the floor. Retained a bit of blue outside giving a color contrast with orange/brownish warmth inside.

No tonemapper mostly done with tone equalizer.

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Edited with Ansel.
I like @Popanz’s approach, although in a place dominated by darkness, broken only by two small windows, the eyes tend to adapt to the darkness. But the perception remains that we are there, in a dark place with only two tiny windows that allow us to “guess,” but not “see.”
I don’t understand the dark part of the window on the right… Could it be boarded up?


DSC01629-small_hdr.exr.xmp (84,0 KB)

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I interpreted it as another similar build… (maybe wrong)

This is not an artistic take. It’s a technical demonstration of how far you can push things while maintaining a natural look in today’s software.

Cropped and converted to tif in GIMP, processed in RawTherapee 5.13.

  • Dynamic Range Compression to make the contrast more manageable
  • Exposure adjustment
  • Tone Equalizer to compress all the tones into SDR
  • Tone Curve for contrast
  • White Balance
  • Chromatic Aberration Correction and Defringe to control the fringing along the window


DSC01629-small_hdr.jpg.out.pp3 (16.2 KB)

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Yes, that window faces a similar hut with its own window.

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