SL2-S Color Space question in editing

[hansvons]

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I'll be back tomorrow on this, Arthur. Got to prepare some footage to showcase the issue at hand. Looks like I found the error.

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[Photoworks]

18 hours ago, arthur@ashaya.com said:

Exactly what I see. Its more of a style Lut than a translation to a natural color. Are there any Luts from 3rd parties that you guys know of?

You can make your LUTs in DaVinci Resolve .

I tend to overexpose my capture 1-2 stops in log.

here are 2 samples one with my LUT 1.6.1 and natural rec2020 in 1.7.1
you can see a shift in colors in Blues and green and just a little in red. Does not mean one is better over the other, it is just preference.
It would be nice to have a proper input Transform. 
For now I apply the lut in the media pool to all clips and I am ready to edit with good colors, if I want color changes I will go back and change the input LUT with a new one and balance the exposure in color.

The are many techniques to approach it, my colorist friend often start with a Rec709 correction what is more demanding . If they need Rec2020 they just change the setting and the corrections hold for Rec2020.

 

 

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[hansvons]

Hi Arthur,

I've tested L-Log footage in the latest FCP version (10.6x). To achieve proper colours with L-Log footage, set your Library to Wide Gamut HDR, and set your Project to Colour Space / Wide Gamut HDR - Rec 2020PQ. If you don't know how to achieve that let me know.

Import the footage in question and drop it in the TL. The footage looks washed out, which is normal since we have log encoded footage sitting on a video gamma TL. With FCP's colour grading tools dial in contrast and levels to your liking and adjust saturation accordingly. The magic wand tool below the viewer will give you a good starting point when pressing WB. In that workflow, there is NO LUT involved. 

For further investigation, I went through a few common possibilities and issues that may arise when ingesting SL2/S footage. 

The first snippet below is most likely what you have been experiencing and rightfully criticising.

That happens when this is your colour management pipeline: L-Log_Rec2020_Rec709_WB_NormalRec709LUT

And this is what you should be getting (a tad too desaturated perhaps, but an easy fix, colours are accurate):

L-Log_Rec2020_Rec2020_WB_contrast_adjusted

 

 

 

From there on, all should be fine. But for the sake of nerdity I dug a bit deeper:

This is Leica HLG in a 2020 TL. It's a bit heavy from the onset and thus not easy to grade. For high-contrast stuff, however, HLG works nicely and colours are accurate.

HLG_Rec2020_Rec2020_full_WB_gamut_grade

But when imported in ACES, HLG can be selected as a generic 2100 HLG Camera IDT, which is a viable way if ACES and Leica should be working together. The magenta tint is probably due to sloppy white balancing.

HLG_Rec2100HLGCCamera_ACES_WB

And finally the result when you ingest L-Log in ACES with the appropriate Rec2020 Generic Camera IDT. The colour is off and can't be meaningful balanced (I double checked). That's the reason why a proper Log IDT for Leica is needed (like we have it with Arri Log-C).

L-Log_Rec2020_ACES_WBcontrast_adjusted

 

 

 

Edited November 23, 2021 by hansvons

[art-fuse]

Thank you so much Hans ( I hope I got the name right) and Photoworks. I'll be looking into it as soon as I free up my workload. Very helpful indeed!!!

[hansvons]

4 hours ago, hansvons said:

And finally the result when you ingest L-Log in ACES with the appropriate Rec2020 Generic Camera IDT. The colour is off and can't be meaningful balanced (I double checked). That's the reason why a proper Log IDT for Leica is needed (like we have it with Arri Log-C).

I made a mistake. L-Log in ACES works as nice as HLG. The magenta tint was was sloppiness on my side (triple checked it, the nailed it). For an ACES workflow, the flat image is somewhat awkward. But nonetheless it works. Sorry for the confusion.

[sblitz]

I am new to all this, what software are you using to do this work?

[hansvons]

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I use Autodesk Flame, a finishing and compositing application with over 25 years of long roots in the advertising and film/VFX industry. It has the most profound and most robust colour management I know. But you can do similar workflow tests in DaVinci Resolve, which is, as a grading application, even more of a commodity in the film industry with similarly deep roots. Then there's Baselight and Mystica, both grading systems catering to the high-end, which Flame does too. Resolve, on the other hand, is for everyone, Hollywood and the aspiring YouTuber because its basic version costs nothing and runs on Mac, Windows and Linux.

[camouflage808]

Thank you all! ...This thread was the first I found that really helped me out!

Once I found out about Rec.2020 to be the (input)colorspace of SL2 and SL2-S, the DaVinci Resolve Workflow does make absolutely sense for me. Til now I was grading 'by hand' or from scratch and I never had real confidence about my Leica colors...

Now, I purchased another very easy helper/extension for this workflow, for me this was a game changer, maybe you will like it too...

Using ACES Colorspace Settings, you can now get an IDT for L-LOG: (14.50 Euros)

https://xtremestuff.net/store/leica-l-log-transform/

or using it as a LUT (i.e. in a 'mixed' project): (18.99 Euros)

https://xtremestuff.net/store/leica-l-log-ofx-plugin/

... both are definitely worth the money for me!

mny greets from Vienna and thx again for this thread!

Tim

https://www.instagram.com/camouflage808/

Edited February 13, 2022 by camouflage808