darktable ep 057 - The Filmic RGB module

Great explanation ! Just a couple of precisions there : 1. about the "center the histogram" approach, connected to the scene grey level… It's what we call the "grey world assumption". If you look at a naturally-lit scene (like a landscape at noon), the average luminance is supposed to be middle grey (18 %). That's the assumption that your camera lightmeter does too to setup the auto-exposure, and it's the safest bet we have when no other information is available. Now, it's obviously a wrong assumption when you shoot high-key, low-key, etc. (and that's why your camera auto-exposure fails in these situations too). So, don't put too much meaning in that. It's not a rule, it's a guide. 2. about the Lab vs. RGB workflow… Lab is a colour *model*, that aims at putting into maths language how human beings percieve light (by decoupling brightness stimulus from colour stimulus). The problem is this model is valid only for a contrast of 100:1 or a dynamic range of 6.5 EV. So, first of all, for all the physically-defined operations (connected to reverting sensor noise or lens blur or atmospheric haze), this is not suitable at all because we need to work on the "physically meaningful" data, which is scene-linear RGB. But then, as cameras dynamic range keep increasing (more than 14 EV now at 64 ISO), we are using Lab way outside of its range of validity, and the results of the pixel pushing in this space become unpredictible and really ugly most of the time. The benefit of RGB is you can push it hard, it's stable no matter the dynamic range. Lab can still be used for gentle edits on HDR files (HDR being anything more than 6.5 EV), but it's really not a sane default space for a sensible workflow.

[@audio2u]

Thanks for that, Aurélien! Good info.

[@wido123123]

Hi! I was the one asking and this is a good answer. As an IT guy, i know that RGB makes a lot more sense in the physical (i.e. chip demosaic and Bayern pattern), but while editing photos Lab was way more understandable to manage.

@Claude Dumas working in CIE Lab is shit and has always been. Lab is a color model designed to predict color perception, not a color space designed to push pixels. CIELab has been proven to shift hues, that's why better color adaptation models (IPT, IPT-HDR, JzAzBz) have been continuously developed since Lab (1976…). But they are still not pefectly hue-invariant, especially when working in HDR. so that myth around CIELab is plain bogus and fake news from people who lost touch with color psychophysics research since 1976.

[@JM-sn5eb]

Love your videos! Usually on youtube there are "tutorials" like: I'll set this to value of... and this to value of... and I'll see what will happen. People have no idea what they doing. Your videos are completely different and so much better. Thank you for your work!

[@audio2u]

Thanks for the kind words!

[@billkossmann9246]

Thanks Bruce - the Darktable series is a terrific resource! I know I'm late to the party with regard to commenting on this particular video, but I find I learn best by researching just enough to get into trouble, making a mess of things, then revisiting the learning material once again.

[@audio2u]

Bwahaha! Sounds like me! :)

[@deka811]

Bruce, you are really good teacher and instructor! This is one of the best explanation I have ever watched on youtube about photo processing. You have a clear concept of presentation and you do it in an understandable and interesting way. I will spent a lot of time on your channel learning of darktable.

[@audio2u]

Wow, thanks! Glad you found it helpful!

[@charleshacker765]

You really wrapped your head around that one well! It has a lot of different things going on, but you were able to bring it together very nicely for us! Thanks so much!

[@audio2u]

No worries! I had to do a LOT of study before recording this episode. Had to watch Aurélien's video twice, stopping frequently to write notes, that kind of thing. Glad it was worth the effort! 😃

[@lephotographelibreblog6331]

your video is very useful as a complement to Aurélien's very technical explanations, thanks for your time

[@audio2u]

No problem! 😃

[@leona_devon]

Thank you for taking us through this module, not on version 3 yet, but good to know its there, hope you are well, watching the terrible fires over there, can't image what it must be like, stay safe all.

[@audio2u]

Thanks Leona! Been a scary summer down under, for sure.

[@michaelrambousek2774]

I've watched Aurélien's explanation videos about filmic and filmic RGB some weeks ago and as you said it goes deep into the tech - which is perfectly fine but made me feel being unsure if I understood the modules correctly. Now finally you came up with your explanations of the module and I'm glad to see that we have made the same experiences. Thanks for that and keep up the good work!

[@audio2u]

Thanks Michael! Mind if I call you Bruce to save the confusion? 😃

[@michaelrambousek2774]

@@audio2u I'd prefer to let you go first ;-) thanks for asking :D

[@audio2u]

You understand the reference, don't you?

[@michaelrambousek2774]

Obviously i do not. Never mind ;-)

[@audio2u]

Ahh. Apologies. It's a Monty Python thing. 😃

[@jrnine]

Hello @all, in my little history of watching tutorials, me as a programmer IT Nerd and math guy, always wants to know, why i have to do this or that. When i understand it, it could be that my brain saved it, so that i can recap it at a later time. Now, i watched from the beginning this series. I can remember, there was one tutorial which impressed me, and that was a guy who make an Elite Dangerous series, hours and hours, which i watched and which impressed me. Bruce, for me, this is one of the best series i watched in my live. I learned so much, as i am a beginner in photography and i am happy that i can watch lots of stuff until the end. Nothing in the series technically and athomsperically, which drives me crazy (exept the beep sound, which you mentioned earlier as .. birds? ;-). Greetings from germany, Jörn Rinkl

[@audio2u]

Thanks so much for the kind words!

[@Lysergesaure1]

Hi Bruce, thanks for this video. I was feeling a bit lost with darktable 3 and your explanations help me. You are a good explainer and have a pleasing voice!

[@audio2u]

Thanks! 😃

[@candidonthestreetanupamgos5283]

Thank you for sharing the Filmic RGB. Cleared several doubts. 👍👍

[@jirinovotny5580]

Díky!

[@audio2u]

Thank you so much!

[@instant_mint]

You're such a good teacher! This helps me a lot. Thank you!

[@audio2u]

You're very welcome!

[@folmonty]

Feels like I just went to school. Your explanations to the module were really well stated and put in layman terms. My error when first using it was getting the gray point correct (or not, which was my first mistake). What the tabs represented also threw me sideways. Essentially trying to use the module like the old filmec but it's completely different in execution. Filmicrgb is so nice for the reasons you stated up front. Getting that saturation S curve. Digital photography has a way of driving so many aspects of the image into the extremes that I've started enjoying the ability to manage them more like before. Maybe it's my age, maybe it's trying to be different. IMHO it just looks more authentic. Thanks Bruce for making this understandable!

[@audio2u]

Cool... glad I could help! :)

[@philsilverman7431]

Another great tutorial Bruce, many thanks, stay safe, thinking of you and all the Aussies at this terrible time, we're seeing horrific images on the news, best wishes from England

[@audio2u]

Thanks Phil. Yep, not a summer anyone is going to forget any time soon. 😥

[@bernym4047]

Thanks for a very comprehensive description. Not am module I'm likely to use though.

[@audio2u]

Fair enough. Each to their own! 😃

[@christianpeyrusse794]

Thanks Bruce for those clear explanations.

[@audio2u]

No dramas!

[@davidknowles5519]

Brilliantly clear Bruce thanks I watched the techie video which was also very helpful, just need to play now. Perhaps you should write a dark table for dummies book. Thinking very much of Australia just now and hope the fires are extinguished very soon

[@audio2u]

Thanks David!

[@wido123123]

Thanks for another great tutorial Bruce. I never used the old filmic module because it felt to unpredictable with my camera, but this module may be more useful. Also, your second image made me remember that you are Aussie, I feel terrible about the bushfires and I hope they stop soon

[@audio2u]

Don't we all! This is a summer no-one will forget any time soon!

[@wido123123]

@@audio2u yeah, sad summer is sad

[@tnargs57]

Thanks Bruce for this great tutorial. Since you did it, M Pierre has released a style called "Auto-filmic - Aurélien Pierre.dtstyle". I am trying it out and it has some really interesting preset choices. It not only presets the filmic RGB module (with only 10% latitude, fairly steep contrast, and Luminance Y for chrominance preservation) but also preset Exposure module (in Automatic mode and target level of -4EV) and preset Colour Balance module (with Contrast +10% and output Saturation at 125%). The result of using it as a starting point is fairly 'strong' and often quite dark, I'm finding. I thought this video might have covered it, but now I realize that the release of this tutorial 2 months ago made that impossible. I believe the idea of this Style was to help with quick 'starting point' processing for DT users. I would be really interested if you would give a mini-tutorial on using it. Obviously using it is easy -- click a button -- but whether you think it really does help with quick DT processing, and what tips you might have about what to do next if one does use it as a starting point. Thanks

[@audio2u]

Looks like I've got MORE homework to do! :)

[@wulfreusch4525]

Thank you very much!!

[@Adrian-ww2jj]

A strength of RAW shooting is the ability of recovering details in the extreme darkness or light parts of the picture. With the RGB Filmic module the results I got in recovering details from darken parts of picture ware very poor. The best results I got with the shadows and highlights module without using the RGB Filmic. Actually with RGB Filmic I didn’t succeed to enlarge the latitude or to increase the contrast without clipping the shadows. Any attempt to bring out the details in the dark part of the picture (by me brown) results in a milky brown and loose of structure on the white walls.

[@audio2u]

This doesn't surprise me at all! Filmic RGB is not designed to help in this regard. It was designed with the intention of delivering an image (from a RAW file) which matches as close as it can get, to an in-camera jpeg. Different horses, different courses! 😃

[@emrg777]

Funny Bruce I often observe a substantial difference in the color preservation modes....and it looked like you got it in your histogram but not your preview....seems interesting....what do you have your histogram profile set at working or output??

[@audio2u]

Ummm, yeah, let me get back to you on that! 😃

[@Tom-rp8qb]

Thanks a lot for the great work!

[@audio2u]

Thanks Tom!

[@PeterLavender]

Hi Bruce I just want to say this was one of the best explanations of the filmic module. There seems to be a related workflow to using filmic with using color balance and tone equalizer. As to your last photo with the over exposure, did you try pulling back the overall exposure with the exposure module? Thanks for a great darktable resource.

[@audio2u]

Don't remember, to be honest! I probably did but the raw data was cooked.

[@JohnMoelholt]

Hi Bruce Thanks for the super videos you are doing on darktable. I have a problem with Filmic RGB, it very often blows out my highlights. Compared to LrC, which keeps a better colour in very light areas, Filmic RGB just blows them out to pure white. Have you experienced similar, and do you have any good ideas to "save" the highlights. Best regards John

[@audio2u]

Sorry John, I've not had that result on any of my images. What is LrC?

[@okay1904]

The filmic module is one that I really have not gotten to use effectively, it does not have parallels with anything else so pretty hard to relate to previous knowledge. Its hard to tell exactly what aspect of the image will be adjusted by any of its controls. One of the issues is, there is no explanation of what advantage it confers over any other approach., or what kind of exposure strategy is the module designed for - ETTR, or ETTL, i.e a photo taken with shadows protected or a picture taken with highlights protected? If the advantage was clearly understood, maybe I'd use it again.

[@audio2u]

Fair enough. If you are happy with a display-referred workflow, I'd say keep using it! Really, you should be comfortable with the software you use. Otherwise, what's the point?

[@Ronbo765]

Hi Bruce. I wonder if you could post a video on the workflow RAW images that are shot for "exposing to the right" for DT 3.0 ? Or, are we still using the Shadows and Highlights module?

[@audio2u]

Aurélien had suggested that we should not be using the shadows and highlights module these days, as darktable moves toward an RGB workflow. But just to be clear, when you say "expose to the right", you mean shooting so as to not clip any highlights at the time of capture, right?

[@Ronbo765]

Bruce Williams Photography By ETTR, I mean pushing the in camera histogram as far to the right as possible, before clipping, and then in post, bring down the exposure and pushing up the shadows. The idea being we get less noise in shadows. So, If we aren’t using shadows/highlights anymore, what would the equivalent process be in DT? By the way, there is a good article on the subject at www.dpreview.com/articles/6641165460/ettr-exposed. I am no expert on it!

[@audio2u]

Wow. That was a great read! Got me thinking a LOT about how I should shoot moving forward!

[@Ronbo765]

Bruce Williams Photography I thought you would like it. It’s a bit fidly, but seems to work. Let us know what DT modules you use in post.

[@dmitrymyshkov811]

I could not find such an option as middle-gray luminance in the 3.8 version.

[@audio2u]

Filmic RGB gets updated with every darktable release, so it's quite possible that parameters have changed, been added or omitted. I'll aim to do a new video on that module when darktable 4 comes out next month.

[@prebenrasmussen6571]

Hi Bruce, I was watching this video again, but noticed that the middle grey luminance slider has disappeared in DT version 4.0. How do you set the middle grey in version 4 then?

[@audio2u]

The current approach recommended by Aurélien is to use your exposure slider to set your mid-tone. Ignore any clipping which might occur because of the exposure bump, and then use the white relative exposure and black relative exposure sliders to dial in the amount of highlight- and shadow-compression that you need.

[@prebenrasmussen6571]

@@audio2u Not sure I understand exactly how to adjust the middle grey with the exposure? But actually also found out (after spending some time with the filmic rgb module) that in the options you can checkmark "use custom middle grey values", which brings the slider back again in the scene part of the module 🙂

[@alphabeta448]

Hi Bruce, thanks for the video. It's very useful. BTW did you notice after release of v3 that, if you drop a gradient in a drawn mask, then hover it with the mouse and scroll the wheel, it curves? I just discovered it by mistake and it's freaking amazing! Was that already a thing in v2.X ?

[@audio2u]

Not aware of that. I'll have to check that out. Cheers.

[@chhil]

Gradients always curved before if you had lens correction on. Not sure if it was part of the 3.0 release, its part of the ongoing 3.1 dev where you can specifically change the curve with the scroll.

[@danielspenner3683]

Hi Bruce, great video as always! I still have some uncertaincies though. The most urgent one is: do you choose an area that equals 18% grey for your greypoint setting or an area that SHOULD equal 18% grey. In high dynamic images this can be of great importance. In your video the images do not have such a high dynamic range. Therefore your greypoint is set by an area that already corresponds to 18% grey. How would you set your greypoint in a mire high dynamic setting? Courious about your opinion! Your work is worth every cent of support. Daniel from Germany

[@audio2u]

You want to select an area that SHOULD be 18% grey, not necessarily what already IS 18% grey. Hope that helps! :)

[@danielspenner3683]

@@audio2u Thank you so much. It helps me understand my frustration about trying out the filmic module over and over again. Later greypoint adaptation usually led to better results, but then why should I set it to any given value beforehand? Only now have I come to understand the logic of the module and the nature of my error. That's great!

[@audio2u]

Excellent!

Thank you very much Bruce! Whats your propose : It is usually needed to activate and use the base curve or exposure modules with filmic modul?

[@michaelrambousek2774]

According to Aurèlien base cure shall be disabled when working with filmic RGB. Furthermore of that make sure that you set exposure levels and white balance correctly before using filmic RGB

[@audio2u]

Exactly.... No base curve, and set exposure and white balance before enabling filmic rgb.

[@MrKhagbr]

bruce, can you speculate on reason why filmic modue does not work on W10? when turned on, the image disappears and the module is unresponsive.

[@audio2u]

No, sorry, I can't. I only run darktable on Linux. Might be worth sending an email to the darktable-user mailing list. Aurélien (who wrote the coffee for that module) will most likely be able to help.

[@bcelasun]

@@audio2u ... who wrote the code... :)

[@audio2u]

Hahahaha! Took me a while to understand what you were getting at! I won't correct it, as it would ruin the flow of the thread! :)

[@bcelasun]

@@audio2u :))

[@prakashkhanchandani9144]

Bruce, in the original video on Filmic, you had explained that demosaic had to be set up in a specific way. Is it no longer relevant to the new Filmic module?

[@audio2u]

Good question. Aurélien didn't mention that in his video on filmic rgb (unless I missed it!), so perhaps not.

[@rainbowrae267]

What happened to the desaturation curve in 4.2?

[@audio2u]

Not sure what you mean?

[@bgnicolas]

This is a very good introduction to the filmic rgb module. Thanks! One question I do not see the base curve automatically applied. Is there a setting to do that?

[@audio2u]

Neither filmic not filmic rgb should be used with base curve.

[@bgnicolas]

@@audio2u Thanks.

[@JillesvanGurp]

And yes, there is a setting to control whether the base curve gets applied by default or not these days. I have it set to not do that. Look under core options for the auto-apply-* settings. I turn all of them off by default.

[@BillWohler]

Why not? Is it that the base curve is poor in general, or is there something about filmic in particular?

[@audio2u]

Bill, have a look at the episode I did on the Base Curve module. There are times when it will clip RAW data, and you're better off without it.

[@samueljames5167]

Have you had issues with the eye dropper freezing Darktable? I use it in the white balance module for spot, and it consistently freezes. Hasn’t do on this before 3.0 versions

[@audio2u]

No, haven't had any issues like that here.

[@mickehog76]

Soon filmic v4 will be released with Darktable 3.2 in August! 😁

[@raybriggs4529]

Hi Bruce.I have just purchased Dark table, what I would like to know please, is it possible to do "Focus Stacking" not HDR Many thanks.

[@audio2u]

Whoever took money from you for darktable is a fraud and a thief. It is FOSS (free and open source software) and licensed as such. As for the focus stacking question, I'm not entirely sure about that one. I suspect the answer is no, but maybe search the site at darktable.org

[@raybriggs4529]

@@audio2u Hi. So sorry i used the wrong word I did download it for free, why i said purchased i dont know

[@audio2u]

Good to hear! 😃

[@audio2u]

Thinking more on this, if you're on Linux, Hugin would be your best bet for focus stacking. It is also great for panoramic stitching.

[@candidonthestreetanupamgos5283]

Having one more problem with darktable. Every time I switch to the darktable from lighttable, the top panel that contains lighttable, darktable and other panels disappears. Must have clicked somewhere accidentally or something is wrong. Can you suggest how to bring the panel back. But it comes back when I double click on the image and lighttable opens up and other panels also show up.

[@chhil]

There is an arrow/triangle present at the top center that you can click multiple times to get various parts of the header. Or you can go to preferences->shortcuts->global and see what the short cut key is to toggle the header, its CTRL+H.

[@audio2u]

Or try ctrl+shft+t.

[@candidonthestreetanupamgos5283]

@@audio2u ok. Will give it a try.

[@candidonthestreetanupamgos5283]

It worked on punching the tab button.

[@MysteriousNightLife1]

Where do you find Filmic RGB? I can only see Filmic. Darktable 2.6.3

[@audio2u]

In darktable 3.x! 😃

[@MysteriousNightLife1]

@@audio2u Yea I realised that after I posted it and couldnt find it to delete it haha.

[@candidonthestreetanupamgos5283]

Is zone system removed in darktable 3.0???? I'm unable to find it

[@audio2u]

That's a good question. I wasn't aware of it having been removed, but I suppose that is possible. I know the new tone equalizer is designed along the same lines, so maybe have a look at that module.

[@candidonthestreetanupamgos5283]

@@audio2u Wait. Just found it. From the more modules drop down menu at the bottom of the modules panel. It's not directly there in the main categories.

[@lorenzotravaglio]

Thank you very much Bruce! I have just one question: it is still needed to demosaic the raw image before proceed with filmic RGB, as you recommend in ep. 26?

[@audio2u]

To the best of my knowledge, yes. But I'm thinking, doesn't darktable apply a demosaic by default anyway? Need to check on that....

[@michaelrambousek2774]

In my copy of DT demosaic is automatically applied and It's not possible to deactivate it. You can just modify the demosaic method.

[@audio2u]

Yeah, I thought as much! Thanks Michael.

[@lorenzotravaglio]

I apologize, I did not correctly explain my thoughts. I meant, it is stil recommended to use the same settings indicated in ep. 026 at 3:07, i.e. AMaZE demosaicing algorithm, color smoothing one time and local average for match Greenpeace, or in this case there is no particular indications?

[@audio2u]

Aurélien didn't make any reference to it in the new video, but he did say that other than the active color space, no other part of the code has changed. So I'm guessing, stick with that earlier recommendation.

[@SergiiStarodubtsev]

no mid grey in 4.0 ...? never stop changing interface.. now it is called "white relative exposure". ever changing terminology? another thing: my filmic rgb has only 1 graph not 2

[@lavawolf666]

a pro is that is better for the machine resourses

[@audio2u]

Sorry, not sure what you mean?

[@Valleedbrume]

So you shoot shit,and simulate it to be ?No offense great video.You actually do understand the subject matter.

[@audio2u]

You're saying my photography is shit? OK. You're welcome to your opinion. We're all at different stages of development of our art.