out of the box RAW rendering not up to JPEGs

bdarcus · January 18, 2020, 12:18am

Is there any possibility of adapting the former to the latter?

ggbutcher · January 18, 2020, 12:41am

If you follow the procedure @Elle Stone outlines here:

https://ninedegreesbelow.com/photography/articles.html#profile-digital-camera

you’ll make a linear gamma profile for your camera that’ll work just fine in a linear workflow.

Indeed, you need the color part of this work for any raw processing, as converting to sRGB or other output profile requires an input color profile that represents the camera’s spectral response. In an ICC profile, the tone part can be effectively nullified by making the tone curve a “gamma 1.0”, which is what the -am parameter in @Elle’s colprof command does.

asn · January 18, 2020, 2:17am

You don’t need the tone curve. darktable-chart has been improved lately and on exporting the style you’re able to select which modules you want included. You can just export the LUT if you want and it should work just fine.

asn · January 18, 2020, 2:19am

It is better to use darktable-chart than producing an ICC profile.

asn · January 18, 2020, 2:21am

You can just use the LUT and go with filmic.

MStraeten · January 18, 2020, 10:57am

its not exactly the same:
example for “famous canon colors”:
1: just color lookup table created by darktable chart
2: color lookup table with tonecurve created by darktable chart - similar to ooc jpeg
3: filmic adjusted to get a similar greyscale; preserve chrominance = no
4: filmic as 3 but preserve chrominance = rgb power

in case of 3, filmic + preserve chrominance = no, you can tweak the yellow tone by increasing output saturation about 10% in color balance, but then the blue tones are ways too saturated
For different picture styles different fine tunings needs to be done to get a result similar to ooc jpeg - manually instead of just using darktable chart to give you a decent style

asn · January 18, 2020, 11:26am

Looking at your chart picture 100% it clearly has glare. The resulting camera profile is pretty much useless and probably the reason why you have issues with your blue tones.

MStraeten · January 18, 2020, 11:51am

this chart wasn’t used to create the profile … but with the applied style (lut+tonecurves) it matches the ooc jpeg…

asn · January 18, 2020, 12:27pm

The tone curve is just created by comparing the grey ramp and setting the points accordingly in the tone curve. It has nothing to do with the color reproduction …

It will match JPGs which are made under similar lightning conditions.

anon41087856 · January 18, 2020, 12:38pm

Both are intimately correlated. The tone curve alone will affect the saturation in non-linear ways. Then, the LUT will revert that.

asn · January 18, 2020, 12:47pm

@anon41087856 Isn’t the tone curve calculated and then unapplied on the color patches?

anon41087856 · January 18, 2020, 12:48pm

I don’t think so. That would make no sense.

asn · January 18, 2020, 12:55pm

github.com

darktable-org/darktable/blob/master/src/chart/main.c#L1012-L1049

    
      
          #else // rgb tonecurve affecting colours, too
            tonecurve_t rgbcurve;
            // ownership transferred to tonecurve object, so we just alloc without free here:
            cx = malloc(sizeof(double)*num_tonecurve);
            cy = malloc(sizeof(double)*num_tonecurve);
            cx[0] = cy[0] = 0.0;                           // fix black
            cx[num_tonecurve - 1] = cy[num_tonecurve - 1] = 100.0; // fix white
            for(int k = 1; k < num_tonecurve-1; k++)
            {
              float DT_ALIGNED_PIXEL rgb[4], Lab[4] = { 0.0f, 0.0f, 0.0f };
              Lab[0] = grays[6*k+0];
              dt_Lab_to_prophotorgb(Lab, rgb);
              cx[k] = rgb[0];
              Lab[0] = tonecurve_apply(&tonecurve, Lab[0]);
              dt_Lab_to_prophotorgb(Lab, rgb);
              cy[k] = rgb[0];
            }
            tonecurve_create(&rgbcurve, cx, cy, num_tonecurve);
            free(grays);

This file has been truncated. show original

anon41087856 · January 18, 2020, 1:08pm

Inverting means applying the inverse curve, and not every curve is mathematically invertible (it needs to be a bijection). Unless some part of the curve building ensures strict monotonicity, this code is dangerous.

Nor_man · January 19, 2020, 8:13pm

I like to share my workflow with DT3.0:

I created different profiles for my camera to match the ooc jpg rendering. (Muted, Neutral, Portrait Landscape…) This way I can apply different styles to one picture and can choose which looks best for further processing. You even can combine those styles with filmic rgb if you choose settings like this (which are nearly complete neutral):

then you can compress dynamic range with white relative exposure or lighten up midtones with middle grey luminance.
@anon41087856 it would be nice if we could set black relative exposure to -18 or maybe -20 or do you have other settings which have really zero effect to the image?

For the profiling with darktable chart i set the input color profile to linear rec709 RGB because this way I later have absolutely no trouble with those blue LED Lights (like the bridge). But I need two or more instances of color look up table (always with 49 patches) to get results nearly perfectly close to ooc jpg. I run darktable-chart a second or third time with the C-LUTs created before. (I recommend to correct the first C-LUT manually if needed in DT)

The finished style looks like this:

And this is one of the results (left jpg - right RAW):

for me its the best compromise:

different good looking starting points really close to ooc rendering in one step
no messing around with “ugly” blue colors
can use filmic and toneequalizer which are huge improvements
If included those user created styles and auto-applyed to matching RAWs: great first experience for dummies using DT the first time

edit: here are the files if someone wants to have a look:
https://drive.google.com/file/d/1PKPaAawwNaxJTLZTuun3MbFn2pOGBCik/view?usp=sharing
https://drive.google.com/file/d/10Yr3jEiGdJReI6cZJB7euwuyETzcW_PF/view?usp=sharing
https://drive.google.com/file/d/1LqUkjwIYkBG7KIXSwZsLKunx_NpvSety/view?usp=sharing
CC BY-SA 4.0

anon41087856 · January 19, 2020, 11:54pm

That tells me you didn’t understand the purpose of the tool. No current camera has more than 14.9 EV dynamic range at 64 ISO, so these values don’t make sense. Logarithms can’t deal with zero input (what is zero energy ? a black hole ?), and filmic shouldn’t be pushed that far. For zero effect on the image, disable the module.

Nor_man · January 20, 2020, 8:26am

sorry, I have expressed myself incomprehensibly. what I do is combine the color lookuptables and tonecurve created with darktable-chart with filmicRGB. the only task in this workflow for filmic is to rescale the dynamic range without adding contrast.
for this I need a preset in filmicRGB which initially has almost no influence on the picture. I have deactivated the curve in the “look” tab of filmic as far as possible. in the “scene” tab the settings as shown in the screenshot above are the most neutral (but not 100%) I have found. from this point I can now rescale the dynamic range as required.

i know tonecurve is working in Lab and this is sometimes problematic but it works 95% of all cases. if it doesn’t work I still have the option to deactivate the tonecurve and set everything with FilmicRGB.

Entropy512 · January 20, 2020, 2:21pm

I really dislike this, as in many cases, it causes people to blame the camera for deficiencies as opposed to “undocumented Adobe magic”. For example, Sony cameras, when using LR or C1 default profiles, are widely regarded as having issues with rendering of non-Caucasian skin colors. In general, it’s something that goes away if you profile the camera yourself.

anon41087856 · January 21, 2020, 12:26am

Set contrast to 1 in filmic look tab, then latitude to 100%, then save that as a preset.

priort · January 26, 2020, 3:35am

@anon41087856 I have seen in your video that you recommend LC after Filmic but I see it actually comes before in the pixel pipe. Is that because it was too hard to change without messing again with the module order…if it gets dragged after and you save that as a style will it still execute after or will the style use the default order?? Just wondering…