SL2-S Color Space question in editing

[art-fuse]

Advertisement (gone after registration)

Hey everyone. I'm a new SL2-S owner, trying to understand something about the color space of this camera.

I see that  the SL2-S L-log lives in Rec. 2020 space, so I set the project to Rec 2020 and applied a Lut. So things look good. But I have Canon log2 footage, which I'd like to add to this Rec 2020 timeline for editing.  Will there be any color issues? 

Edited November 11, 2021 by arthur@ashaya.com

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[hansvons]

No. Not for the SL2-S, whose colour is Rec2020 based. But I had to check how Canon Log2 looks in Rec2020. I'd search for a  LUT LUT that transforms Canon Log2 to Rec2020. Quite likely that Canon provides such a LUT; rec2020 is the future video space, after all.

The best would be to look out for a colour managing common denominator like ACES. That way, you tag the Leica footage with Rec2020 in the IDT list and the Canon Log2 footage with Canons proprietary ACES Canon Log2 IDT. Mixing camera brands is a typical use case for why ACES has been developed.

[art-fuse]

Thanks so much. This is a bit new to me. Will research further. Just got the SL2-S. Still not sure if I'll keep it as the battery is not as efficient as I would like. And cages seem to be non-existent. 

[hansvons]

I use the SL2-2 for video professionally for smaller projects. It has three advantages over the competition. 1) sturdiness, 2) handling, 3) colour. The latter is highly subjective. But if Arri's colour science makes sense to you, Leica's colour will be your friend. Otherwise the competition does everything better, especially when it comes to AF. But if you don't need AF (I don't, am used to manual focusing) and like the colour, the SL2-S is a good choice. 

I have 4 batteries. Rarely used more than 2 on one day. 

There are several cages around. There's a thread on this forum on cages for the SL2/s.

[art-fuse]

Will be reading up now. Thanks again.

[art-fuse]

I played around for a while testing the colors vs my Canon C70. I seem to be getting more accurate colors with the Canon. I've been spending a bit of time tweaking the Leica files to get the right color accuracy. When applying Natural_Rec 709 Lut in FCP (Input Rec.2020 / Output Rec.709) I get more contrasty and warmer tones. A bit more video-like. Not natural at all. The greys are always warmer as well. Using custom WB with a grey card.

Using Leeming Lut for Canon Log 2 delivers a much nicer image to my eyes. I really wanted to dump my r5 and the C70 for one camera, but now I'm not sure. I love the still from SL2-s, but the video seems to require more work in post for me. Unless I'm totally missing something here. 

 

[hansvons]

Advertisement (gone after registration)

Hi Arthur, when using L-log and for input Rec2020, and your TL is set to HDR, the fitting LUT must be the Rec2020 LUT. The Rec709 LUT works only in a Rec709 context from A-Z. With the Rec709 LUT, in Rec2020 the colours are off. Skin tones show a magenta cast and the sky has a distinct hue to cyan.

Give HLG footage on a colour managed Rec2020 timeline a try. The HLG flavour somewhat incorporates the L-Log LUT. It truly is the best of both worlds. It should also work on a regular Rec709 TL. On a Rec709 TL, there's a little chance that you will be loosing DR in the highlights, depending on how the NLE is colour managed. But Premiere Pro works with HLG nicely, so does Resolve. Others might too (my Flame loves HLG) but I didn't check yet.

HLG is a great option for anyone who isn't looking for a super high-end solution but for a workflow that takes advantage of the wide DR in 10 bit having compatibility between SDR and HDR, and that doesn't require LUTs. HLG grades much quicker than log, as it is already gamma encoded. But compared to SDR video/Rec709, HLG uses Rec2020's vast colour space with slightly lifted shadows and extended highlights. 

BTW, selecting Generic HLG Camera as an IDT with HLG footage works nicely in ACES, showing accurate colour and usable contrast.

Lastly, much of colour accuracy depends on WB and BB. Not every NLE has sufficient tools to achieve that. But when my Leica footage is properly white and black balanced, I get cinematic skin tones I really, really like. 

You can PM me anytime and I walk you through this.

 

[art-fuse]

I'm using FCP and My project is set to Rec. 709. I mostly shoot everything manual, including the WB, using my grey card. So now if I place a clip on my timeline, apply Custom Lut and select Natural_Rec709 Lut, I start to see more pronounced reds, and the highlights seem to be harsher than I'd like. I do use the Convert option (Input Rec. 2020 since that's the original space, and Output Rec 709) If I don't use Convert, then of of course colors are all over the place. I see how on Vectorscope the skin tones are leaning more towards the reds from the skin line. Not overly, but seems to always lean there. 

Looking at two images (C70 and SL2-s) I see that Leica is leaning greener and Canon slightly magenta. The Canon colors are still more correct on this beach scene. Please see attached. 

https://www.dropbox.com/sh/p46piriez3h90hw/AACvu6BxdMjEjzsVBHj_Nb7ca?dl=0

 

 

[hansvons]

As it seems, you have done everything correctly. I've put the Canon and Leica picture in C1. While the WB of the Canon picture was off (-300K and - 4.2 tint) according to C1, the Leica picture is spot on. The WB brings the Canon picture closer to the Leica picture, still the typical differences remain: Leica renders sky blue always cooler, more in the Prussian blue direction than towards ultramarine. Greens (foliage) are more saturated and cooler. Skin tones tend to be less orange. In general, colours seem to be more separated. 

Personally, I like the Leica colour more, it's closer to what I get when shooting with Alexa. Others prefer the Canon approach, because it's warmer and makes skin looking more healthy (what I don't want, it somewhat equalises the persons complexion by adding some "healthy" orange tint). Of course, in post you can change everything to (almost) what ever you want. 

Have you used the same lens?

 

[Photoworks]

I didn't find the Natural LUT from leica to be that Natural. I see a shadow color shift to cyan.

the Classic and Natural lots provided are more style LUTS to me

[Slender]

15 hours ago, arthur@ashaya.com said:

I'm using FCP and My project is set to Rec. 709.

in FCP, Make sure LIBRARY is set to Wide gammut color space.

Set your PROJECT to which ever output setting you want for you L-Log to come out, just be aware of selecting the good options (Input-Output -the latter should be same as your timeline and export, logically) for your clip.

[hansvons]

2 hours ago, Slender said:

in FCP, Make sure LIBRARY is set to Wide gammut color space.

Good point! Which is, essentially, Rec 2020.

[art-fuse]

8 hours ago, hansvons said:

As it seems, you have done everything correctly. I've put the Canon and Leica picture in C1. While the WB of the Canon picture was off (-300K and - 4.2 tint) according to C1, the Leica picture is spot on. The WB brings the Canon picture closer to the Leica picture, still the typical differences remain: Leica renders sky blue always cooler, more in the Prussian blue direction than towards ultramarine. Greens (foliage) are more saturated and cooler. Skin tones tend to be less orange. In general, colours seem to be more separated. 

Personally, I like the Leica colour more, it's closer to what I get when shooting with Alexa. Others prefer the Canon approach, because it's warmer and makes skin looking more healthy (what I don't want, it somewhat equalises the persons complexion by adding some "healthy" orange tint). Of course, in post you can change everything to (almost) what ever you want. 

Have you used the same lens?

 

The lenses are different. Used Leica 24-70 and Canon 24-70. I think one of my concerns is the sky color, which is more correct on the Canon. I see that the blue on the Leica is not as correct. And yes, one can change everything in post, but the less work - the better, right? 

[art-fuse]

4 hours ago, Photoworks said:

I didn't find the Natural LUT from leica to be that Natural. I see a shadow color shift to cyan.

the Classic and Natural lots provided are more style LUTS to me

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?

[art-fuse]

3 hours ago, Slender said:

in FCP, Make sure LIBRARY is set to Wide gammut color space.

Set your PROJECT to which ever output setting you want for you L-Log to come out, just be aware of selecting the good options (Input-Output -the latter should be same as your timeline and export, logically) for your clip.

So you are saying that the Library should be WIde gammut? But what if I place additional clips from other cameras on the same timeline? I've been working on a documentary for few years and you can imagine I've shot with few cameras making this doc.

[Slender]

😅 for advices about matching cameras for video in an NLE, please wait for the wise science of Hans, maybe... I have less age/wisdom/experience for multicam work as my background is either fiction or high-end docs film shot on (1 type) of movie cameras (film/digital). I am essentially an AC/Aspiring DOP/Stills_Unit_On_Set with much of my background in the shooting phase of the production, not post-production.

 

 

[hansvons]

Hi Arthur, at that point it's unclear for me how to proceed because we're entering personal taste. For perspective, below there are two little projects (the first is a footage rough cut) I shot in a one-band manner on the SL2-S on L-Log internally at ISO800 and WB set to 5500K preset. The lens is the formidable 24-90. All shot's have been graded on a Rec 2020 TL, using the Leica Natural Rec2020 LUT at the end of the grading nodes. Shooting on HLG would led to the same result without the need of the LUT.

 

 

 

[hansvons]

13 minutes ago, Slender said:

😅 for advices about matching cameras for video in an NLE, please wait for the wise science of Hans, maybe...

Nothing wise on my side here. ACES is the Academy's answer on matching different cameras on one TL. Canon supports Aces with its different Log flavours, so does Leica when shooting HLG by using the generic HLG Camera IDT. That being said, FCP does not support ACES to my knowledge. But it supports with the Wide Gamut setting Rec 2020, which the C70 and the Leica both benefit from due to the wider colour space. For the Leica, HLG is my favourite gamma when convenience and a large DR are important. HLG renders the Leica Natural LUT on Rec 2020 obsolete.

[Advertisement]

Hallo,

Look here: Leica L-Mount

[art-fuse]

Thank you so much for your input guys. I will play around more. That SL2-s grows on you. 

[art-fuse]

OK, here is another test - Wide gammut Rec 2020 Timeline, 2020 Natural Lut. WB = daylight. The blue sky is totally off. It's like teal or something. There is a color cast as well that is not natural to the scene. Maybe it's the Leica look. I don't know. The scene looks stylized, not natural.

 https://www.dropbox.com/s/fpvsl5bdn9h0aj0/Screen Shot 2021-11-22 at 5.02.20 PM.jpg?dl=0