Hello, I’ve read this blog post (CIECAM02 for capturing the color of the light?) and I want to do the same thing. What I’ve tried is using Temperature correlation white balance, then enabling CIECAM16 without touching anything and modifying the viewing conditions temperature to the same value as the white balance. This seems to work, but I think I’m doing something wrong. What’s the best way to do what I’m doing on not so recent RT Nightly?
Hi p2swfwrdj2,
Welcome to pixls.
You’re not telling us why you think you did something wrong. Without that it’s a bit hard to point you in a direction.
You do mention using Temperature correlation; This isn’t always the best solution and as mentioned by Elle The colour of the light is a rather important starting point, whichever your goal: correcting or “real”.
To give you an idea how I approach this:
I general like to start with setting my WB as close to Daylight lighting/neutral white as possible.
(I might do things in between, see the last paragraph)
Then I go to CIECam 2002. Set complexity to Advanced, CAM Model to CIECAM16, mode to Automatic Symmetric, WP Model to Free temp + tint + cat02/16+ [output].
Next step is to make sure that both Temperature fields are set to the same value as the WB Temperature value.
This is my baseline to start working with this module. I do at times change the Temperature values when editing, though.
One other, maybe unrelated, thing that might be important to know: CIECam 2002 is nearly at the end of the processing pipeline, so if you first use CIECam and then change, for example, Colour Toning settings you might get really surprising/unwanted results.
BTW: I agree with Elle, No. 3 is best 
My goal is to get the same color of illumination as was seen by the eye. For example, if a scene is illuminated by an incandescent light source, white will be seen as yellow-ish. This is what I want, not when white is totally white at any lightning condition. I don’t currently need any other tools CIECAM module has.
I think I do something wrong because I change the viewing condition settings and I’m not sure this is right. Again, it works, but probably not what should be done
Hope that clears that up
Let me start by saying that there is no right/wrong when the end-result, after looking good and hard at it, reflects exactly what you are after.
That being said…
There is, of course, a certain way to approach things that would make overall editing life a lot easier and more predictable.
Assuming for the moment, with the Nine Degrees Below link in mind, that a neutral profile is started with and only the WB module and CIECam are being used the “correct” way to work would be:
- set the correct WB using the White Balance module. As mentioned before don’t rely on either of the out-of-the-box (auto) presets. At this point you should already be rather close to what colour of light you are after (neutral white or scene lighting).
- Set CIECam02 to Advanced, CIECAM16 and Automatic Symmetric (Use CIECAM16. CIECAM02 has a few issues you might run into).
- Use the Scene Conditions section to fine tune the colour of the light to what you are after. There is no default you can fall back upon: The first to settings in the WP MODEL section, combined with the CAT Adaption slider are a rather good start. The Free temp + … setting gives you the most freedom but is the hardest to get right.
At this point you should have the colour of light you want/need. The rest of the CIECam module options, mostly indirectly, do influence colour but aren’t really meant to dial in what you are after.
The Viewing Conditions section is important in as much that this is the place where you dial in the specifics of the environment and/or device that the image is going to be shown in/with. This is done with the previous edits made in the CIECam module as a starting point.
As you might have guessed you could just ignore Scene Conditions and Image Adjustments sections a go straight to Viewing Conditions and adjust the colours/tint/luminance there. But you would not be able to do any adjustments in the 2 “ignored” sections afterwards without having to redo the Viewing Conditions settings as well. So this might be seen as wrong, but if this is all the final editing that you want/need to do it isn’t wrong when the end-result is good.
Thank you, it’s much clearer now. My mistake was setting white balance to “white is perfectly white” rather than “white has a tint”. Now when I use, for example, 5000K white balance and enable CIECAM with Automatic symmetric mode and any WP model the image is close to the actual color I saw.
Could you please tell me which workflow is more correct - the one I did earlier or the one that I tried now if both work for me?
Not the quick answer but likey the best one is …try a range of lighting for source images and see how each workflow performs …you may find you need more than one depending on lighting or if you can find one it might be a tweak of what you do now in order to better work across a wider range fo lighting…nothing beats experimenting…
I agree with @priort.
I like to add to that that you should not get into the habit of creating a fixed/static way of working.
As an example I refer back to my earlier posted remark about Temperature correlation. Sometimes that is the best one, but you’ll notice soon enough that the other 2, Camera and RGB Grey are also “correct” at times and you might even have to adjust Temperature and Tint manually.
Having an overall and roughly standardized way to approach an edit is OK, but each RAW is unique and needs its own individual tweaks and edits. The power of RawTherapee is that it can do, what looks like, the same thing in many different ways. Some work in certain situations and do not work in other situations.
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Thank you, I’ll start experimenting then 