DCamProf - a new camera profiling tool

[AlterEgo]

I did, no luck.

what is the camera in question ?

[markanini]

what is the camera in question ?

Canon G9 and Olympus SP-510UZ.

[torger]

Where can I find a good all-round tone curve for RawTherapees perceptual mode?

Try this file: http://www.ludd.ltu.se/~torger/photography/files/acr.rtc
It's an (almost) exact copy of Adobe's default curve, and it's a fine curve.

[markanini]

Try this file: http://www.ludd.ltu.se/~torger/photography/files/acr.rtc
It's an (almost) exact copy of Adobe's default curve, and it's a fine curve.

It keeps more saturation in highlights in perceptual mode than the the built-in tone curve in Adobes profile(tone curve enabled under DCP). I can appericiate the difference on slightly overexposed portraits. Nice!
EDIT: I noticed some changed hues on saturated colors in my shots, I can't tell if the changed hues are more accurate on top of Adobes profile but so far nothing looks objectionable.

[torger]

It keeps more saturation in highlights in perceptual mode than the the built-in tone curve in Adobes profile(tone curve enabled under DCP). I can appericiate the difference on slightly overexposed portraits. Nice!
EDIT: I noticed some changed hues on saturated colors in my shots, I can't tell if the changed hues are more accurate on top of Adobes profile but so far nothing looks objectionable.

The perceptual curve in RawTherapee is basically a copy of an older version of the DCamProf built-in tone reproduction operator. As it's an older version it does have some issues with clipping extreme colors, you can have very deep saturated blues turn magenta. At some point I'll update the perceptual curve in RT to come closer to the current DCamProf, but there's also a performance requirement when using it in RT so it's not feasible to bring over it unchanged, ie it's quite much work.

[markanini]

Sorry if this has already been covered. I tried making a quick profile for my Pentax *ist DS from Nikon D50 SSFs which uses the same sensor with these commands:

dcamprof make-target -c D50_istDS-ssf.json -p cc24 target.ti3

dcamprof make-profile -c D50_istDS-ssf.json target.ti3 profile.json

dcamprof make-dcp -n "Pentax *istDS" -d "D50 Pentax ist DS neutral" -t acr -g adobergb profile.json D50-Pentax-ist-DS-neutral.dcp
dcamprof make-dcp -n "Pentax *istDS" -d "D50 Pentax ist DS neutral+" -t acr -o neutral-plus.json profile.json D50-Pentax-ist-DS-neutral-plus.dcp

I'm pleased with what I'm seeing as i A/B with the Adobe standard profile, the only "fault" is a relatively high lightness for very saturated colors pushing them into clipping. Probably more of a subjective issue with the limited display gamut being at the root of the issue. I uploaded my profiles and a few example shots if you want to take a look: https://www.sendspace.com/filegroup/Gn8pVnV8JQ8SkaU7%2ByyPUKnu150DDgcQErkX04hq%2FdA

EDIT: I posted a general Adobe Standard vs. DCamProf Natural+ gallery: http://imgur.com/a/Dzqur/all

[torger]

Some commercial profiles have a very strong gamut compression to avoid such issues. DCamProf has gamut compression too when you for example provide "-g adobergb", but it's quite weak. I may at some point look into making a stronger compression to make profiles that work more similar to the commercial when it comes to high saturation colors.

To make a very robust profile to work in all sorts of light conditions and colors you should make an unnaturally desaturated profile, which is a strategy Adobe is using on some cameras, like the A7r-II and Pentax 645z. This means that you don't get "finished" color to start with though.

My current ability to work with DCamProf is limited though so it's probably not happening much new things with it for a while.

That said I've looked at the example files you provided and to me it looks like the clear difference between DcamProf/Adobe for the D50 with your example pictures is that Adobe turns the high saturation reds towards orange and DcamProf stays red. The amount of clipping for AdobeRGB color space is about the same though, so to me it looks like it works as it should for those images. I'm a bit rusty on this, but if I remember correctly the saturated reds going orange is part of the "Adobe" designed subjective look, so you find that in many(most?/all?) of their profiles.

Note that some clipping is intended even with gamut compression. While you can easily make a "mathematically correct" gamut compression so there's never any clipping it doesn't make images that look good. If there's only one channel of RGB that's clipped the color usually works well anyway, and you get some more range to play with in terms of brightness. If you want to test and see how a gamut compression that doesn't clip looks you can set
"RGBChannelHighLimit": 1,
"RGBChannelLowLimit": 0,
in the gamut compression configuration. Read more in the example file data-examples/ntro_lookop_conf.json

[markanini]

I'll check that out. While I'm working on perfecting my SSF profile (dual-Illuminant, checking for optimal lut relaxation, WB shift fix) can you make a recommendation of a virtual target better than CC24, if such a thing can be said to exist?

[torger]

I'll check that out. While I'm working on perfecting my SSF profile (dual-Illuminant, checking for optimal lut relaxation, WB shift fix) can you make a recommendation of a virtual target better than CC24, if such a thing can be said to exist?

While the software itself is rich in SSF features I haven't worked that much with them myself as most my focus has been on making profiles the traditional way when I've made own profiles.

You can play a little with the built-in targets, but to make an "ideal" target one would probably want to have a balanced set of not too many spectral measurements, so focus is put on "important" colors. I have no such ready-made target. The CC24 is a good starting point for sure. As long as the target has decent coverage, like the CC24 has, the target has less effect on the result than one may think. Why commercial bundled profiles look so differently is due to subjective design and how colors are modulated to match the film curve, the target used has less importance.

[markanini]

New Adobe Standard vs. DCamProf Neutral+ gallety: http://imgur.com/a/Dzqur/all

[Bart_van_der_Wolf]

New Adobe Standard vs. DCamProf Neutral+ gallety: http://imgur.com/a/Dzqur/all

Subtle saturation and some color differences. But it's not clear which is the Adobe and which is the DCamProf version. Could you add that info?

Cheers,
Bart

[markanini]

Subtle saturation and some color differences. But it's not clear which is the Adobe and which is the DCamProf version. Could you add that info?

Cheers,
Bart

The first image is always the Adobe Standard version. Easy to tell by the darker shadow tone. Try the fullscreen link for easy A/B-ing.

EDIT: Differences that jump out at me: More salmon-red in the shadows, less cyan blues, much less blue purples, and orange-red less shifted to red.

[torger]

The first image is always the Adobe Standard version. Try the fullscreen link for easy A/B-ing.

EDIT: Differences that jump out at me: More salmon-red in the shadows, less cyan blues, much less blue purples, and orange-red less shifted to red.

It's a quite big difference on the train, blue in Adobe, purple with DCamProf. Which profile is closer to the truth? I've seen that with some sensors, like the NEX6 it's been very hard to get the hue correct on deep blues, I'm not sure the CC24 target is ideal for that. With the NEX6 I made a manual target adjustment to get a good hue, it's described here how you do that: http://www.ludd.ltu.se/~torger/dcamprof.html#make_profile_deep_blue

The other examples looks as I would expect them to do, cyan skies is an "Adobe look", saturated reds also tends to be orange, it's warmup thing in their look. Seems like it's a slightly different contrast curve that the Adobe has darker shadows.

It's normal that differences are relatively small, especially for low to medium saturation colors.

[markanini]

Which profile is closer to the truth?

Definitely the DCamProf version. Some pretty accurately rendered shots [EDIT: As far as the purple hue goes]of the same type of train: http://www.postvagnen.com/forum/index.php?mode=thread&id=626184 http://postvagnen.com/forum/index.php?id=699902

[Tim Lookingbill]

Definitely the DCamProf version. Some pretty accurately rendered shots of the same type of train: http://www.postvagnen.com/forum/index.php?mode=thread&id=626184 http://postvagnen.com/forum/index.php?id=699902

Then your definition of accurate is not in line with what I've seen in nature for over 50 years first as a fine art painter and now color matching shots of colored objects taken near my display for A/B comparison without relying on memory of the scene.

But at least I get to see what others get with Adobe Standard that I don't get with my Pentax K100D vs a CC chart generated custom DNG profile.

[markanini]

Then your definition of accurate is not in line with what I've seen in nature for over 50 years first as a fine art painter and now color matching shots of colored objects taken near my display for A/B comparison without relying on memory of the scene.

But at least I get to see what others get with Adobe Standard that I don't get with my Pentax K100D vs a CC chart generated custom DNG profile.

If you think my statement wasn't limited to the question of the purple hue of trains then you are reading way to much into it.

[Tim Lookingbill]

If you think my statement wasn't limited to the question of the purple hue of trains then you are reading way to much into it.

Torger asked which of the image samples you linked to affected by Adobe Standard vs DcamProf was closer to the truth. You said the DcamProf was closer to the truth.

That's the statement I'm addressing according to how you define truth. Maybe you need to be more specific on how you define accurate to truth colors.

It boils down to how much work do you want to put into getting accurate colors. I'm seeing a thread that is disproportionately requiring way too much time over just fixing it in post with HSL and white balance.

[Tim Lookingbill]

If we're all going to be subjective on what colors should look like I can guarantee with certainty a profile whether canned, custom DNG or a DcamProf version is not going to fix subjective-ism.

One says a color should look a certain way because it's accurate according to the photographer's memory of the scene which adds another variable to color definitions and another disagrees. How can a profile possibly fix this or even come close to defining memory colors?

It's a waste of time IMO.

[markanini]

For your purposes it may be a waste of time. For me it helps my work flow. Having accurate colors from the start saves time on troubleshooting wrong colors when you dont have the convenience of having the object you are reproducing next to your monitor.

[AlterEgo]

Having accurate colors from the start

how do you know that they are indeed accurate though ?