Let's learn Filmic RGB! Your one stop shop to understanding filmic-based approach to edits!

This is my favorite preset but I didn’t want to distract too much from the theme in the above examples so I used a simpler version. :wink:

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Thanks for your videos, very inspiring!

One “tweak” you used in almost all examples was to use color calibration and then in brightness you pulled up the red and reduced the blue. What is the reason for this ?

Greets
Jürgen

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For the three sliders in the first Filmic module tab I have a mnemonic :grinning:

Think about the “scene” tab as about a bandoneon:

You can pull or push only (or first) the left hand (white relative exposure) or right hand (black relative exposure) or or both simultaneously (dynamic range scaling) and then left or right again.

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Ok, let’s see…

  1. Without:

  1. Red lighter blue darker:

  1. Blue lighter red darker:

Prize question 1: What is the difference?

Prize question 2: What did I want to direct the viewers to with version 2 and to what with version 3? :thinking:

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I have to confess, Filmic RGB has not been easy for me. I like the capabilities it offers, but I also often struggle with it, particularly with regards to hue changes:


DSCF6544.RAF (32.1 MB) DSCF6544.RAF.xmp CC-BY-NC-SA

This is a simple enough picture of a fire, and the remnants of our “Christmas Tree”. Most of the fire is clipped in one or more channels.

My problem is, as soon as I enable some variant of “preserve chrominance”, this happens:


RGB euclidean norm

luminance Y

max RGB

RGB power norm

Furthermore, I tried to use “middle tone saturation” as a general saturation control, and do not like the way it pushes highlights towards white:


filmic RGB middle tone saturation +10%

color balance output saturation 110%

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Another thing I find confusing about filmic RGB:

trees
_DSF1845.RAF (21.3 MB)
_DSF1845.RAF.xmp
CC-BY-SA-NC

This image has bright and dark parts. And I like to adjust the darkness of the dark parts and the brightness of the bright parts with filmic’s “black relative exposure” and “white relative exposure”. However, while “black relative exposure” mostly changes the darkness of dark parts, “white relative exposure” changes both bright and dark parts.

For example, here is the same picture with “black relative exposure” lowered by two EV:
lowered shadows
Notice how the highlights look very similar to before (86.46 vs 86.85 L* on the bright bark on the left) but shadows changed visibly (18.72 vs 16.13 L* on the dark tree trunk in the top left quadrant)

And here is the same picture with “white relative exposure” increased by two EV (and black relative exposure reset):
raised highlights
Highlights are lowered (77.35 vs 86.85), but crucially, shadows are now much lighter (22.15 vs 16.13).

There are probably sound technical reasons for this, but it leads to “white relative exposure” acting more like an overall enlargement of dynamic range than a localized adjustment of (mostly) highlights. “black relative exposure” however acts mostly on shadows.

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Lastly, I often like to adjust my contrast using the “contrast” slider in filmic RGB.

default contrast

Inevitably, this leads to part of the transform becoming orange, indicating lightness reversals.

increased contrast

Thus I lower “latitude” until the orange goes away.

reduced latitude

However, the latitude adjustment requires no thought, and is a purely mechanical response to the orange in the curve. Frankly, it should be automated. Perhaps by introducing a “contrast priority” checkbox next to the latitude that auto-adjusts latitude to the highest non-reversing value. Or perhaps with a change to the underlying spline that “tightens the bend” sufficiently to fix the reversals.

But more than an inconvenience to my editing, it makes a one-dimensional contrast adjustment into an iterative procedure of balancing two variables: Increasing “contrast” increases punch in the image, decreasing “latitude” decreases punch. So what should be a “drag the slider until contrast looks pleasing”, is in reality “drag the slider until contrast looks pleasing, then drag latitude until it is no longer orange, then back to contrast, then back to latitude, etc.”.


Despite these three negative posts about filmic RGB, I want to state clearly that I like filmic and the scene-referred workflow a lot. It is a fantastic module, and produces outstanding results!

I am merely pointing out gotchas (and workarounds!) I discovered in my work that probably trip up other people as well.

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Thank you for very useful workflow videos. Unfortunately, they have no tone recording, am I right? Your clipping indication is active as I always do, too. Which clipping preview mode do you select, “any RGB channel”?

Latitude/contrast aren’t the only way to fix these issues though. For example, you can also use the “shadows/highlights balance” as well as a number of items in the display and options tabs. So how do you decide which way to automate?

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I will be careful here and separate it a bit: This is not about the difficulties with Filmic but primarily about dealing with a cardinal mistake of the photographer. The highlights are overexposed and in these areas there is no information about two important color channels red and green. The darktable now has to make up for this and reconstruct the missing data. This is an almost impossible task and it is no wonder that one struggles with it.

And just to clarify - when I say “cardinal mistake of the photographer” I don’t mean you directly, but anyone who photographs intensively, including me, regardless of skill. Such things happen all the time.

That being said, does this look any better to you?

DSCF6544.RAF.xmp (7,7 KB)

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Hi @Redbrook, and welcome to Forum!

Yes.

Yes.

Indeed.

  • “White relative exposure” changes: White- and black-point and midtone-contrast by shifting
  • “Black relative exposure” changes: Blackpoint, midtone-contrast slightly by shifting, highlight contrast(slightly)
  • “contrast” changes: midtone-contrast, blackpoint and whitepoint (slightly)
  • “hardness” changes: shadow/dark-, midtone-, highlight-contrast and blackpoint (slightly)
  • “Latitude” changes: shadow/dark-, midtone-(slightly) and highlight-contrast
  • “shadow/highlight balance” changes: shadow/dark-, midtone- and highlight-contrast, blackpoint(slightly)

This is not an exhaustive list, meaning: I did not try all combinations of parameters, nor all parameters, but only the quickly accessible ones. Also, as you mentioned, certain parameter combinations give inversions and clipped values. Some of these can be mitigated by switching to cubic splines.
To ‘learn’ the theory behind the sliders I suggest practicing a lot as well as looking at the resulting curves in @jandren 's tonecurve-explorer https://share.streamlit.io/jandren/tone-curve-explorer. Or, as others have suggested, make working presents and use them without fine tuning them too much after application.

EDIT: I should clarify: the “by shifting” expression used above means that it shifts the contrast slope that you have either up or down, effectively changing the contrast in the midtones.

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I think this encapsulates my struggles with filmic, and I can see hundreds of Lightroom refugees running away right now saying “I just want to set my black and white point” (which is almost instantaneous in Lr by double clicking the Black and White sliders respectively). There are just so many ways to adjust tonal values and countless combinations within filmic and I find it hard to “remember” what the best or my preferred ways are to go about setting the dynamic range I want. Note that this is not a criticism of the module, because such fine control is truly amazing, but I personally share some of @bastibe’s struggles.

One might expect that the white and black relative exposures should work the same way, but on opposite sides of the tone curve. But as @PhotoPhysicsGuy points out, this is not the case. Hence, I juggle between the sliders to set my black and white points and to get the look I want. I’m sure this is user error at not understanding the module properly, but I feel it’s a common struggle with less advanced users. So, to be more specific in line with the rules of this thread, what is the expected way to set your black and white points if you’re trying to maximize dynamic range (e.g. max black and white without clipping)? Is it even best done in filmic?

Adjusting contrast has also been one area of confusion for me. I find that the spline almost immediately registers an inversion when I adjust contrast in the Look tab, which means I almost immediately adjust the latitude to undo this inversion. This means I sometimes go straight to color balance to adjust contrast there instead. And maybe that’s not a problem. Is there any expert opinion on the “best” place to adjust contrast? Or is this simply personal preference?

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I think you are right and others can weigh in…but filmic sort of removes local contrast and trying to recover it with contrast in filmic might compromise other aspects of your filmic application to the image so I think using other means to achieve contrast is the way to go…I am sure others can weigh in but I think maybe people trying to adjust and achieve contrast using that slider in filmic might be some of the issues people are having…

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I kind of go the other way at this and consider my latitude and how big I want it to be. I might tweak contrast but I usually back off if the indicators show clipping and just add contrast with tone eq, color balance, local contrast and contrast eq or a combination…I rarely mess with filmic contrast too much.

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You’ve got it exactly right! Look bite the videos that I have sent.

Let’s try it this way. I will not be able to explain this mathematically, but as I understand it as a layman.

This is the initial situation without filmic:

Shematically, I only transfer a part of the dynamic range of my camera to the sRGB color space:

Now, I have also set filmic so that there is no compression. The look of the photo does not change almost at all:

If I now increase the exposure by one EV, the shadows are getting lighter and I get the warning that I have left the sRGB gamut in highlights:

So, we have this situation now:

Now with white relative exposure I bring the highlights back into the gamut. (Note that the shadows are affected because of the compression):

Now we have this situation:

Now I want to expand this darker compressed area a bit with black relative exposure until I have enough contrast in this area:

This is how it looks now:

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Just to make this very clear for people who want to learn the module: @s7habo 's simplified graphs is at the moment ever so slightly not how the module actually works. You can see this for example in the last step of his actual screenshots how adjusting “black relative exposure” also changes things a bit in the midtones and a bit more in the highlights.

So to all the learners: expect some “crosstalk” of the sliders. Don’t be frustrated if that happens, it’s how it works at the moment. In that regard the module is a bit more iterative than what you might be used to or what you expect.

But, and that’s the important part, everything else that @s7habo showed is exactly how many people would use this module and how it can give fantastic results.

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I find that ev mapping graph a nice way to understand it and as you have pointed out you can see shift and changes in contrast by the slope and spread of the mapping lines between the scene and display ev zones…I think this map is good for beginners because you can see that the graph does not change if you crank up exposure…18% is mapped to a lighter value but the relative mapping to white and black does not change…if you did this to a histogram with a levels display you would see the difference…I think many people still have that sort of relationship in their heads…

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I agree with the first part. This is how a curve works (filmic is a glorified curve adjustment).

I disagree with the iterative adjustments part. As @europlatus said, we aren’t dealing with the white and black sliders of Adobe, where at 0, by the way, we aren’t even at a neutral starting point. It isn’t about bending specific tones to one’s will. For that we have tools that deal with local contrast, colour or tone; e.g., local contrast, colour balance or tone equalizer. In contrast, filmic adjusts light ratios and roughly sets the shadows, mids and lights to where it makes sense for our nonlinear eyes. Therefore, it is more of a “set it and forget it” kind of module rather than a “tweaking until I get all the tones I want” tool.

A useful illustration would be to picture a slinky toy or mechanical spring. If you move one segment of it, the rest would sure follow. One could hold or lock multiple sections in place, but at some point, we would be applying unnecessary and possibly harmful tension. In the same way, we can’t have the curve be static / unchanging at other points without bad things happening such as not having enough tones to go around and artifacts.

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Perhaps that is what it should be but then you need to hide all the sliders. It is funny that exposing them is what gives full control but likely also what causes problems with excessive tweaking. I must admit to being guilty of fiddling too much with it just because I can to the point where I can’t decide on what looks better. :slight_smile:

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