With sigmoid you can either adjust the skew or change the “target white” value for valurs over 100% to get contrast back in the upper part of the histogram
sunset_cliffs_with_august-02_23_2025-007-_DSC1912.NEF.xmp (23.8 KB)
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If you increase the Latitude in the FilmicRGB Look tab, it will eliminate the changes in whatever midtone range you set.
@priort – very good point about being sure I’m using the right histogram. Setting the histogram to the export profile does give me the result I’m looking for without having to increase the white point above 100%, as @gigaturbo suggested. Presumably, that’s why what I’m seeing on-screen is blowing out before I max out the default histogram! So that’s that mystery solved, I think.
@AtaraxicShrug – ok so I wrote up a whole thing about the difference in thought process between sound and photography, but Todd seems to have found the root cause of both the blowing out and the not filling the histogram, so I guess it’s kinda moot. I’ll leave it in though because it might still be kinda interesting, at least to you. I wrote it for a general audience though, so there is a lot of detail I’m sure you already know well 
In sound, amplitude is always stated as relative to some baseline, which is a result of the scale we use (dB, which basically just means logarithmic). So, if we’re measuring a voltage, relative to 1V, we would call the units dBV. Or else, we could measure power, relative to 1mW, which we call dBu. This is a pretty good analog to the concept of middle-grey in traditional photography—18.45% is our reference point, in this case, and even the EV notation is just using a slightly different logarithm from dB. However, dBu/dBV/etc. are only really used in the realm of analog signals. As soon as a signal is sampled into digital, we switch to a dB relative to “full scale” (in other words, relative to the largest amplitude that can be represented; dBFS), for basically the reasoning I’ve been going on about haha. Filmic (and presumably sigmoid, though we don’t have visibility into its inner workings), however, still bases things on the (originally) analog notion of middle-grey. And that’s not necessarily a bad thing in the context of photography. The difference being it is a unit that is still fairly meaningful in the digital world since, in both analog and digital, it is a % of some standard, limited range.
@gigaturbo – I can’t believe I never thought to change the target white above 100%! I guess because that’s still kinda going against how filmic is supposed to work. That does get me more-or-less get what I was originally expecting, though.
@kofa – I’ll have to try this thanks!
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I must have completely misunderstood your original post. When you said the highlights (the reds in the histogram) were blowing out, I took you to mean that they were turning white on your monitor even though they were not pushed all the way to the right (the gap you circled) in the histogram. That is a function of how filmic (and sigmoid) desaturate as you get brighter and brighter…after a certain threshold that is. Since you had actually clipped/blown out the highlights, I thought you were wanting to know how to manually change the initial threshold and slope of the desaturation curve.
Glad Todd got you sorted!
There are many ways to tweak this esp for skies and one what I find really powerful with nice results is using the tone eq and just dragging up or down the extreme right node and blending in color channels ie red green or blue …sometimes I will do three instances one for each…here I forget what set of experimental settings I was using messing again with exposure and filmic but on the left you can see some of what you are saying with filmic and on the right is a bit of red added and some blue removed and you get a nice rich enhancement…of course there are other ways to do this and you can decide how yellow or orange or pink you want the sky to be…
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Do you mean using a parametric mask focusing on 1 channel per tone eq instance? Or do you mean using a blend mode (i am not sure what blend mode options are available for tone eq lol) The picture didnt have any tone eq modules shown so i wanted to be sure I understood.
Very sorry for any confusion…there was no masking just the uniform mask to allow choosing the color channel blend mode …you could use a drawn gradient with this for the sky for example but for this suggestion I was referring to using the blend mode by channel…
Got it. I didnt even know there were RGB blend modes in tone eq! Thanks!
Pretty much all modules have blend modes. Which are available depends on how the module works (scene or display-referred, RGB or Lab).
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