Hi’ @ggbutcher and @mbs
Thanks once again for another amazing feedback!
Mee too! And I might add that I sign up for your next class covering color and tone……
!
Interesting, I will try it out in RT. Unfortunately DT doesn’t accept dcp profiles.
The ability to turn off the dcp tone curve in RT is a great feature and as you say, allows you to get more accurate colours. That, plus the ability to use the Exposure module tone curves in perceptual mode gives the best result colour-wise of anything I have tried to date.
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Rt’s neutral profile is not supposed to bring accurate colors. For that you need a camera profile (ICC or DCP).
In RT, ICC camera profile is a legacy.
Camera profile (DCP) is automatically selected if one is shipped with RT for your camera.
In other case, you can select a standard DCP from Adobe or if you are not satisfied, create one (see http://rawpedia.rawtherapee.com/How_to_create_DCP_color_profiles and https://www.ludd.ltu.se/~torger/photography/camera-profiling.html for all arcane technical details).
note: The DCP tone curve should not be selected.
Use of DCP is very simple and required to get accurate color at the beginning of processing. ( you need also white balance which is more tricky)
The display of those colors is an other story.
That is an artistic choice
You are right, but for the starting point I personally prefer to use the perceptual mode. We are fortunate to have the choice.
It’s not only an artistic choice. The perceptual tone curve is much slower than the non perceptual tone curve. That may be an issue when processing a large amount of files in queue.
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I have an Adobe DCP landscape profile originating from the DNG converter. I used the profile in some of my examples in this thread when using RT.
The DCP menu contains a number of check boxes: Tone curve, Base table (greyed out), Look table and Base line exposure (checked in my examples).
Checking Tone curve and Look table on/off in results in the following in combination with the RT neutral processing profile:
What do you think? Comments and “explanations” will be much appreciated……
RT 5.7 allows you to apply Hue and Luma masks in its Colour Toning module. Here’s a screenshot showing the effect of putting blue to the lightest areas of the photo with a luma mask:
If you apply the Adobe DCP, it is probably for the look it offers (you prefer it to the default colours). The Adobe tone curve is pretty universal too, so I usually leave these two on, but if I need aggressive highlight recovery I might disable the DCP tone curve and apply my custom tone curve which suits the effect I’m striving for.
Woah there, cowboy…
@Morgan_Hardwood I’d appreciate it if you could enlighten me…
I’ve found that if I don’t use my camera’s DCP, then often the colors I get are different both from my recollection of the scene and the camera’s JPG. Even worse, they often look “wrong” – green becomes yellowish, red becomes purple, etc, especially for colors that were very intense (saturated?) in the live scene.
When using a DCP, I run into these problems much less frequently.
Furthermore, I like to start from a low contrast, low saturation image and add contrast and saturation to my taste. That’s why my default profile is “neutral”, with the addition of the DCP (but without the tone curve), and a few other things thrown in there, such as sharpening.
So far I’ve been getting good results with this profile, but if it could be improved, or if I’m doing something suboptimally, please let me know…
I feel there is still a basic misunderstanding here.
Do not confuse “processing profiles” with “input profiles”. RawTherapee’s default processing profile for raw photos, as well as the “neutral” processing profile, both use an input profile - a simple color matrix at the very least, and all the other stuff a full-fledged DCP contains (ColorMatrix, ForwardMatrix, HueSatMap, LookTable, ToneCurve) if one exists.
Also worth bringing up, to throw a monkey wrench in the works and complicate things more, as anyone who’s used tone curves in RawTherapee knows, the same curve shape can lead to drastically different results based on the tone reproduction operator, the “curve mode”. Accurate (in what sense?) vs aesthetically pleasing. So there’s also that to consider.
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Thanks! I think I understand that, and I know that at the very least a simple matrix from dcraw will be applied.
But, I wanted to reply with some actual examples of color differences with and without Adobe DCP files for my camera, and, to my surprise, things are different from they were three years ago – whether it’s dcraw, RT, and/or something else I don’t know. I revisited some old files where I recalled having color troubles, but I couldn’t reproduce them. Here are a couple of examples where, three years ago, the colors without DCP would have been wrong (both “not as pleasant” and “not as I remember them”). Left-hand side is “camera standard”, and right-hand side is with Adobe DCP Standard for Olympus EPL-5. Nothing has been done to the images except applying the Neutral profile and selecting the DCP (look and base only).
So, I’m about to backtrack: for my camera on RT 5.7, I actually prefer RT’s standard color matrix. The DNG seems to produce slightly yellower greens and bluer reds and purples.
Jim Kasson has a nice study of an Adobe Standard DCP profile for a Sony FF camera, and at the end he quotes Eric Chan (one the Adobe colour guys) – my conclusion from all of that is that when people design a general purpose input profile, accuracy is not their highest priority. Cameras are not meant to be used as spectrophotometers.
And even when camera makers or Adobe design their"neutral" profiles, they are never 100% neutral (accurate) either.
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Hi’ @sankos
This color/profile business is really a complex issue. I observe the following in my dcp example:
Image part 1. Neutral processing profile, tone curve checked
The image is much lighter than the neutral profile alone. Tone curve lightens the image and boosts the highlights. Ok, this is an expected effect.
The colors become strange and reddish. Look at the yellow fields. Not good! Why?
Image part 2. Neutral processing profile, look table checked
Much like the neutral profile without the look table. What is the look table supposed to do?
Image part 3. Neutral processing profile, tone curve and look table checked
The reddish look caused by the tone curve disappears as by magic, the whole image pops and the colors become closer to natural, but much more vivid. Interesting and pleasing but not like real life.
Can these effects be explained and/or in any way anticipated
Thank you for reminding me of the luma mask facility. I remember now having read about this facility but I have only just downloaded 5.7.
Applying a contrasty tone curve to a simple, uncorrected matrix profile creates hue twists and saturation issues (“colors change when you make exposure [SIC i.e. brightness] adjustments”). Look-up tables are meant to correct for those phenomena in a perceptual way (not accurate, but visually pleasing).
It has the look we are accustomed to by years of visual conditioning. The tone curve lightened certain areas and darkened other areas (global contrast) and caused the increase in saturation, and the LUT corrected certain hues in a non-linear way to make the image look “pleasing”.
Hi’ @sankos
Thank you, great!
You can buy a digital camera and start editing your photos. Quickly you will be able to improve your photos considerably………but you have a long way to go before you arrive at a point where you have a thorough understanding of what is happening in respect to color and tone and you are able use the tools as intended.
I am wondering how to identify a systematic approach to achieve this.
Until then I really appreciate the feedback and the responses from the forum….
!
Hi’ @Morgan_Hardwood
Just to make sure I understand you correctly:
The Neutral processing profile and the Auto-Matched Curve processing profiles both use an input profile. In my case “Camera standard” as default . No difference there.
On top of this the Auto-Matched Curve processing profile turn on the Auto-Matched Tone Curve option in the exposure module to match the look of the embedded jpg. The exposure module is executed after the input profile settings.
Correct?
Another question: Is the fixed sequence of execution of modules documented in RawPedia?