filmic, a personal view


#21

Based on @davidvj’s post, the white rel exp - black rel exp = 14.68 - -10.72 = 25.40


(Gustavo Adolfo) #22

@andrayverysame it’s still in dev.

In my case, I installed it from source by following the procedures outlined by the “git version” section of Darktable’s install web page. (not sure if it also applies to Windows, I’m on Ubuntu).

If you’re going to do that, it’s important that you backup all your .xmp files as well as /home/USER/.config/darktable folder. it will be necessary in case you want to downgrade.


(ph. weyland) #23

Could you share the xmp please ?


#24

The problem is how to find a good mid-gray value.
I would do in this way
open the image with neutral setting


in the metada you could read that is underexposed about 2 stop, so we do the inverse (+2 stop )

Here is our mid gray (rawtherapee)

Simple brightness,contrast,saturation sliders and the highlights look a little flat


(Aurélien Pierre) #25

Dynamic range values are tabulated on dxomark.com. For example, here: https://www.dxomark.com/Cameras/Sony/A7R-III---Measurements#measuretabs-3

The XMP are always embedded in the JPEG files, however, as I work on the next version of the module, you might not be able to apply them, to here is a screnshot of the parameters for the guided filter:

Capture%20d%E2%80%99%C3%A9cran%20du%202018-11-26%2007-28-42

(notice that the “preserve the chrominance” option is not yet in master)

Your mid-gray is wherever you want it to be, since the lighting of the scene is not uniform, and that’s the whole point of filmic: remap it.


#26

Sorry but we disagree.
Because this is the Darktable category here’s my edit with .xml


20181020_0038.RAF.xmp (18.2 KB)
Brightness,contrast,saturation and one rgb curve so that mid gray is “correctly” mapped.

No noise amplification, natural looking colors, no posterization


(Aurélien Pierre) #27

The scene-referred mid grey is relative to a specific illumination. In a multi-illuminations scene, you have to choose the reference illumination as the one lightening your subject. Depending what you consider the subject in this picture, your illumination is not the same (reflected on direct light), thus your grey is not the same.

If you use filmic and target a grey that is already at 50 % L, then you do nothing (you remap 50 % -> 50 %), except maybe adding a bit of contrast with the curve.


#28

Or amplify the noise, for a well exposed shot there aren’t any pratical reason to use log gamma.

Log really shining when a photo is under exposed, but if the noise is amplified too much it could be due to a low dynamic range from the camera or that it was choosen an irrealistic mid gray


(Aurélien Pierre) #29

You have other algorithms to deal with the noise. It’s always a matter of trade-off. Every transfer function that raises the shadows will increase the noise (even a simple exposure lift), so this is not specific to the log.

What is log gamma ?


(David Vincent-Jones) #30

Must say that your results make a healthy start to the development process. I must admit that I cropped prior to any processing which in turn may have eliminated some extreme levels.
I am sure that you have a better ‘feel’ for this module than most of us; the logic, despite the manual, is somewhat alien to me at this time … and yes I did RTFM (printed it too).


(Gustavo Adolfo) #31

@davidvj But I think @age didn’t use filmic in his version, just the tools he mentioned…


(Aurélien Pierre) #32

Hi there,

darktable 2.6rc1 should bring a more stable framework to find the best settings in Filmic, with a much clearer curve to read and no more weird jumps between close parameters values. Merry Christmas !


(ph. weyland) #33

The filmic S curve has improved a lot with the 2.6 release. Control points help to understand what happens.
But the curve shape depends on spline curve calculation which sometime doesn’t produce expected toe and shoulder. However this is usally not an issue.
I’ve more difficulty to control saturation especially on landscape. Filmic tends to desaturate highlights. And depending on contrast we get easily shadows oversaturated and washed highlights.
Maybe a specific control of saturation for shadows, midtones and highlights would turn this easier.
This is the kind of image which is problematic for me (dt snapshot, tonecurve based, not too far from the scene I have seen), I cannot get anything close to that using filmic. Any tip ?


20181109_Cahuzeres_221.NEF (26.3 MB)


(David Vincent-Jones) #34

I would agree that there appears to be a significant improvement in the function as of late. I routinely ‘test’ the advantages of filmic against my more conventional multi-step approach.
With a number of my images I find that filmic responds well to the ‘almost automatic’ one-click operation and then needs only fine tuning. However, that said, for reasons that I do not understand on many occasions filmic simply cannot provide any sort of reasonable starting point and working with it is simply a waste of my time.
I question if filmic is a ‘better’ mousetrap or simply an alternate route. Whichever path that I take with my RAW processing I am convinced that filmic is not saving me time in my work and I find that it causes a loss in creative flexibility.
I will continue to play with it and watch future developments with interest.


(Mica) #35

I think it is another tool in a fairly robust tool bag.

It’d be helpful if you explain the “loss of creative flexibility” comment.


#36

A bit dull, so far, but in the right direction, I think?

Have fun!
Claes in Lund, Sweden
– filmic experimenter –


#37

The main thing I would say about filmic is to know what it is and isn’t. If you are looking for a tool that “would solve all of your problems” and “magically fit with every other tool in your workflow”, this isn’t it.


(David Vincent-Jones) #38

I believe that my ‘normal’ multi-step process provides more flexibility than that of filmic where the single module tries to encompass much of the functionality of several modules (such as: contrast, saturation, levels, exposure, tone-curve).
I have found through numerous tests on my own data that, for me, allows greater flexibility.
Another thing that I notice is that attempting to use other modules after an initial usage of filmic may require added time fiddling-about further with the filmic settings.
I am still finding images where the ‘auto-tune’ initiates impossible setting … for instance with a DR that is beyond all reason.
Yes, I do agree that it is another tool in our box … an an interesting one at that. Although it was, I am sure, not designed to be a one-click solution to the RAW process, it still strikes me as having that feeling.


#39

This is what I was able to accomplish with filmic only.

PS @aurelienpierre When lowering balance shadows-highlights, there is a point at which the blue in the shadows of the histogram leaps to the left, and then the shadows, which were desaturating, suddenly becomes very saturated.


(ph. weyland) #40

To go a bit this way, I think filmic would be easier to use if we could gradually activate the features: 1, log curve, 2. S curve, 3. saturation(s)… (EDIT) and see the corresponding effect.

With filmic, and unbreak as well, black color picker (and related automation) is very dependent on the noise which can create artefact values. But it is quite easy to fix this changing the black point (the histogram gives good indication for that; to be more accurate you can use the color picker (min)).
I get also better result when I let some room on both sides (shadows and highlights) in exposure module (no clipping).