SL2-S L-log Grading

[ahendy]

Advertisement (gone after registration)

Anyone using the SL2-S for video — could you share your color grading workflow with L-Log? I'm struggling a bit with it (getting really strong magenta tones and other weird color shifts) and am finding that Leica's LUTs are not even close to acceptable. 

Hoping there's something simple that I'm missing, as I've never struggled this much with Clog or Slog. The only thing that gets me close is FCPx's built in Panasonic V-Log lut, but even that isn't quite right..

 

[Slender]

I am going to summon for you the following SL2s video users (I hope they dont mind too much )

@hansvons @Aaron Daniel @Steven

 

For me, I am happy with the 709 Leica LUTs in FCPX for a basic grading of the SL2 (not S)... with/wo Atomos Ninja.. I even prefer slightly what I got internaly... I don't have (extented) experience grading in HDR/PQ rec 2020.

Surely you know about placing a color wheel (or your prefered method of altering luma/color) on top of the LUT effect help achieve grater control of exposure over the ones you may place beneath, right?

Edited June 17, 2021 by Slender

[BernardC]

Have you tried Leica's LUTs? They can be downloaded from Leica's site (same place you would download a manual or firmware update).

[ahendy]

@Slender indeed yes I'm placing the color wheel before the LUT effect.

@BernardC per my post, I've tried the Leica LUTs and gotten some really terrible results. Massively oversaturated and heavy leaning into magenta/pink especially on skin tones. Certainly I can correct this manually with color wheels but it doesn't seem right..

[Aaron Daniel]

Appreciate the tag, @Slender ! I'm blushing to see that you've put me listed me among these professional idols of mine as well 

@ahendy good question! I think it starts with setting your expectations for yourself and how much you'd like to put into your grade– because it can take as long as you want or as short as you want. For me, in a nutshell, I'm nowhere near experienced with high-end commercial work. My background is in quite simple wedding films or run-and-gun online content, so I don't have too much experience diving deep into industry standard software like resolve or avid or whatever else is out there that I am naïve to 😅

But it's funny you mention Final Cut Pro. That is my editor of choice for both speed and relative features for editing. My workflow is this:

    1. Shoot in L-log, either internally (highest/decent bitrate for your needs) or externally (to the Atomos Ninja V; ProRes)
    2. Once imported into FCP, I don't actually use the LUT option provided by FCP for each clip. I currently use Color Finale and this plugin has the option to apply your custom LUTs or work in an ACES environment. I use the custom LUT option.
    3. I then apply any correcting curves within the plugin. I trust the plugin to apply these curve adjustments in the right order with use of the LUT

I do also notice how there can be a magenta shift when recording L-Log internally after applying Leica's provided LUTs, but I've always found this a relative easy fix to adjust. I always thought it was just me not setting my white balance properly in camera 😅

It sounds like you have experience with Canon and Sony log files, so I find it safe to assume you know what you're doing while working with flat footage like this haha. Something specific I found was that some LUTs designated for Fuji F-Log works really well with L-log. That might just be me and my subjective look at it, but I'd suggest playing around with some F-log LUTs if you have any (which should be easy to find online somewhere too)

Here is my latest example video of using the above workflow:

I hope this helps!

 

[frame-it]

33 minutes ago, Aaron Daniel said:

Something specific I found was that some LUTs designated for Fuji F-Log works really well with L-log. That might just be me and my subjective look at it, but I'd suggest playing around with some F-log LUTs if you have any (which should be easy to find online somewhere too)

 

https://dl.fujifilm-x.com/support/lut/F-Log_LUT_E_Ver.1.19.zip

[hansvons]

Advertisement (gone after registration)

L-log lives in the Rec2020 colour space. Set up your NLE to HDR Rec2020 and all should be fine, assuming that your NLE is colour managing the output correctly. You can also use ACES, input transform is again Rec2020. 
 

Using L-Log in Rec709 colour space will lead to magenta skin tones and other funky colors. Unfortunately, that’s the base colour space of most NLEs, hence your bad experience. But you can take advantage of Leica’s Natural Rec709 LUT in the Rec709 colour space. But you’ll lose dynamic range due to the fact that Rec709 is a smaller colour space than Rec2020.
 

Leica should provide an in-detail cookbook for L-log.

[Slender]

By the way, SL2s users, how high in ISO/ASA are you willing to use your cameras? Just out of curiosity.

[ahendy]

Holy cow you guys are helpful. Thank you, this is incredibly helpful.

First, @Aaron Daniel thank you for the detail here. This workflow is very helpful and interesting. Now I'm getting excited about trying some F-log LUTs.. 

Second, @hansvons this is exactly what was happening - you were spot on. Once I moved to a Rec2020 color space in FCPx, everything popped back to looking normal. No more over saturation, no more funky magenta shifts.. it all looks great now with the Leica provided LUTs and is an excellent starting place for my grade. Completely agree that Leica needs to provide more documentation on this.. unless I missed it, couldn't find much detail on it anywhere.. 

Thank you all for your help and responses. Much appreciated.

[hansvons]

40 minutes ago, Slender said:

By the way, SL2s users, how high in ISO/ASA are you willing to use your cameras? Just out of curiosity.

I think the "native" ISO with the largest dynamic range is probably roughly ISO 800, as we see with many other modern sensors. But I figure that at ISO 3200 there seems to be another ISO step which delivers still acceptable colour in the shadows and isn't too noisy. Gaining 2 more stops can be quite comforting. Higher ISOs above 3200 will bring out more noise and less saturation in the shadows, which is only acceptable for me when in a pinch, eg something crucial must be filmed for a documentary. 

But it's safe to say that the SL2-S delivers in L-log very likely the most appealing colour in its market. Skin tones are astonishingly good and leave no questions whatsoever, similar to the Alexa. Because colours are so good any degradation through higher ISO is more visible compared to the competition. 

Please note that I exclusively use L-log, which seems to be widely de-noise-free. With gamma-encoded video files chances are high that things are considerably different.

[Photoworks]

3 hours ago, hansvons said:

L-log lives in the Rec2020 colour space. Set up your NLE to HDR Rec2020 and all should be fine, assuming that your NLE is colour managing the output correctly. You can also use ACES, input transform is again Rec2020. 
 

Using L-Log in Rec709 colour space will lead to magenta skin tones and other funky colors. Unfortunately, that’s the base colour space of most NLEs, hence your bad experience. But you can take advantage of Leica’s Natural Rec709 LUT in the Rec709 colour space. But you’ll lose dynamic range due to the fact that Rec709 is a smaller colour space than Rec2020.
 

Leica should provide an in-detail cookbook for L-log.

the Rec2020 is the solution in L-Log, the LUT's from Leica work on the SL2 too, maybe a little punchy but a starting point.

 

Another solutions to make you own LUT's in DaVinci Resolve Studio version, you can just shoot a color chart and get the colors to the correct patches. This way you can make proper Monitoring Luts for you atomos monitor.

[Slender]

Thanks very much for your feedback on ISO, with some dramatic differences in appreciation between @hansvons and @Steven as HLG very high V L-Log moderetly high. Much appreciated! I will experiment more with rec2020 space.

[frame-it]

S1/S1R are getting Blackmagic Raw soon, via a Firmware Update, i hope the SL2-S gets that Update too.

[hansvons]

1 hour ago, Slender said:

with some dramatic differences in appreciation between @hansvons and @Steven as HLG very high V L-Log moderetly high.

Yes, I've read Steven's assessment. But it is somewhat predictable. HLG is a gamma encoded hybrid format that works in Rec709 as well as Rec2020, and that is knowingly friendly to noise in the shadows. Often, camera manufacturers in the prosumer market help high ISOs with some noise reduction added to their gamma encoded video files. I don't know hat Leica is doing under the hood but in L-log they seem to do nothing much visible. On the contrary. In L-log, even at ISO 800, there's some fine noise/texture visible, which I appreciate.

[Slender]

@hansvonsnice, thanks again! Do you set your sharpness to 0 or -2 with L-Log? Sorry for so many questions :))

If you like texture the SL2 has plenty lol but even in HLG I can't dream to take it as high as SL2s...

[hansvons]

On 6/18/2021 at 9:39 PM, Slender said:

Do you set your sharpness to 0 or -2 with L-Log

-2. The differences are very subtle. The manual provides no sensible answer why there's -2 to 2 and not 0-5. 

[Slender]

10 hours ago, hansvons said:

-2. The differences are very subtle. The manual provides no sensible answer why there's -2 to 2 and not 0-5. 

Thanks.

Also I wholeheartedly support your want for a L-Log cookbook. Panasonic is much more open on this, but that's understandable Leica is nowhere near such a maverick in video (yet).

[MITDelay]

On 6/18/2021 at 12:38 AM, hansvons said:

I think the "native" ISO with the largest dynamic range is probably roughly ISO 800, as we see with many other modern sensors. But I figure that at ISO 3200 there seems to be another ISO step which delivers still acceptable colour in the shadows and isn't too noisy. Gaining 2 more stops can be quite comforting. Higher ISOs above 3200 will bring out more noise and less saturation in the shadows, which is only acceptable for me when in a pinch, eg something crucial must be filmed for a documentary. 

Is there a setting to set ISO to increase 1/2 or 1/3 stops on the SL2-S? Currently theres only seems to be full ISO stops. I skimmed through the manual but did not see how to set 1/2 or 1/3 increments. 

Edited July 30, 2021 by MITDelay
clarification

[Slender]

I don't think there is a way to to this, unless you are using floating Auto-Iso with one of the variable aperture zoom.

On my SL2(not s), when shooting Log, I get the better results at tne 400ASA (lowest) settings and 3200ASA. Therefore when shooting video in Log, I treat the camera as a Cine-Camera: Most are -truly- best-usable with a single sensitivity (Arri Alexa:800ISO....) or a dual setting (high-low) when fitted with a dual-base-iso circuitry: Sony Venice: 500 or 2500... FX6: 800 or 12800. For this camera, when set to CINE EI, you can't venture outside of either of those values. For "video" use (CUSTOM in Sony lingo), it lets you set it whatever (200-400-800-1600-3200-6400...etc) but you have to know that, conter-intuitively, it will look worse at 6400iso than at 12800.

I suspect Leica is using some kind of dual gain circuitry because you can see the grain decreasing when switching Iso from 1600 to 3200... just like if there was an (un-advertised) dual-gain back-up amplification circuit... or some internal NR kicking-in at this setting.

@hansvons seems to rate his SL2s at 800Asa. You would be better off finding your prefered settings for normal lighting and another one for low light... and do the 1/3rd of a stop adjustments with either aperture or nd filters.... and leave ISO relatively constant if you can. And of course shutter speed mostly alone 🤓

[Advertisement]

Hallo,

Look here: Leica L-Mount

[MITDelay]

Once again, my thanks!

I understand why they allow partial iso stops to compensate for the variable aperture zooms, but its weird how partial iso is possible (with the floating iso feature on), but this camera doesn't allow you to set them.  The feature is obviously there, why couldn't Leica spend a bit more effort to put it in the menu as a parameter.

Edited July 31, 2021 by MITDelay