Hi.
I want to know black point value and white point one that RT applies respectively to each raw file. Why don’t you change RT’s indication method ? I am confident that it will become more transparent and more authentic !
I really don’t understand your question. Perhaps a native english speaker can help out…
RT applies what it thinks would be an appropriate black point value (e.g. 64 in 12bit ) and white point value ( e.g.4095) to each raw file without telling users explicitly. I want RT to show these values.
Currently, RT says that black point value is at zero in default though non-clipped raw files has their black point at a higher level (e.g.128). I want RT to say that it applies 128 as black point.
WRT manual adjustment of the black point, @paperdigits’s link to the black point page in Rawpedia tells you how to do this.
What’s the make/model of your camera? With that, I can find the relevant entries in the RT data files. If you really want to understand what RT is doing here, get a cup of tea, find camconst.json in the RT data, and read the embedded comments. Very enlightening…
Hi Glenn,
Thanks for your intervention.
I feel it too hard for me to analyze internal data in RT.
In my view, there is no disadvantage for RT to show black/white point values to users in an explicit way.
Am I wrong ?
One of the main criticisms (valid or not) is that RT’s interface is too technical. Adding more technicality to it when users’ would rarely adjust the value would be a mistake in my opinion.
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Displaying new things in a program is not always straightforward. Where I work, display changes are the most costly ones. Sometimes finding a good place with enough window real estate is vexing.
In this particular case, inspecting camconst.json, the file where your camera’s black/white points are specified, can be very educational. Before the data starts, there’s a large text describing where these data points come from, and what considerations one might make in determining (and submitting for inclusion) their own. It may be a lot to digest, but I’m more about learning why things are than just accepting what some programmer thinks is good for me (LR, cough, cough… )
If you tell me what make/model camera you’re using to produce your raws, I’ll find its data in RT, let you know where you can find it…
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Hi Mica and Glenn,
Thanks again for your interventions.
One of the main criticisms (valid or not) is that RT’s interface is too technical. Adding more technicality to it when users’ would rarely adjust the value would be a mistake in my opinion.
This is a surprise to me because I thought ordinary people didn’t use RT 
I truly believe that RT is a fantastic software due to its technicality as well as flexibility. If not, majority users would have turned to PS, LR, etc.
But I understand that there exist some users who are fond of simplicity.
Being said that, allow me repeat that I am sure that RT’s raison d’etre stands in its technicality. If it is enhanced by more openness and transparancy, software’s core value will increase further.
If you tell me what make/model camera you’re using to produce your raws, I’ll find its data in RT, let you know where you can find it…
Following your advice, I read some commentary in “camconst.json” file with binary editor. It was helpful but not practical. I have more than a few dozens DSLRs and the number of models continues to increase every several weeks, if not on a weekly basis. And I have known that some models vary their black/white point values in line with ISO value, so it is nearly impossible for anyone to refer to camconst.json every time when he develops raw files.
Finally, I realized that it might not be so easy to change GUI of RT in a shorter term but again want to reiterate that there will be no disadvantage for RT to show actual black/white level values in an explicit way. Those who don’t want to see them can simply ignore them. I guess those who want simplicity in RT are even unaware of them.
I think I’m an ordinary person, and therefore I can’t afford PS or LR. That is why I stick with FOSS. Honestly, personally I think that RT is way better than LR.
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Oh dear. Most of us are not ordinary at all.
/Claes in Lund, Sweden
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Use a text editor.
I agree with you. What you propose does not complicate things to the user in any way, it merely exposes hidden values if not also in fact simplifying things. See:
Curious, why do you need to see these values so often?
Lastly, if you have access to many camera models, would be great if you also had access to a color target and an incandescent tungsten light bulb, then you could send us pics so we could add more DCPs, see:
http://rawpedia.rawtherapee.com/How_to_create_DCP_color_profiles
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Hi everyone,
Many thanks for intervention.
Karlheinz,
I think I’m an ordinary person, and therefore I can’t afford PS or LR. That is why I stick with FOSS. Honestly, personally I think that RT is way better than LR.
For me, it’s not about money. It’s about quality. I feel that RT is more honest and technical than PS and LR as raw file decoding software, and that’s why I use RT.
Beep6581,
Many thanks for consideration !
Claes,
Most of us are not ordinary at all.
Please don’t take my words badly. But in my view, nobody is fully ordinary. More or less, everyone has something abnornal.
Morgan,
Use a text editor.
Oh it’s marvelous !
why do you need to see these values so often?
Well, I mean, my aim is mainly about white point/saturation level. To my experience, black point does not matter so much in terms of raw file decoding if there are a couple of DN differences. But change in white point is visible and sometimes suffers severely.
By the way, it is also often the case that useful data for saturation isn’t included in exif of raw files. Yes you can get it by converting a raw file into DNG format. But it means you get what adobe thinks appropriate. I have some doubts about what abobe does, if not for all the models I have. So I want to be explicitly informed of the fundamental on which I develop raw files.
On black point, I just assume that there is no reason for actual values to remain tacit. It’s simple as that.
if you have access to many camera models, would be great if you also had access to a color target and an incandescent tungsten light bulb, then you could send us pics
I am more than happy if I can contribute to RT’s team. In fact I tried to take pictures of ColorChecker several years ago. Due to my failure of accurate or proper lighting, however, I couldn’t manage to produce good dcp files. So yes, I am willing to try again and send you raw files once my surroundings get stable. But please wait for some time as I am now living in a foreign country and it will take a couple of years to return home.