RAW S-Log Colors are off with NEW S-Log LUT and NEW Resolve settings.

G

Gene Sung

Veteran
So my cool shoot got axed at the last second because the production company could not secure the permit, so I spend the last two days pixel peeping like a mad man.

First of all, the 4K2HD looks GREAT. I LOVE it, but I am having trouble now converting 2K and 4K RAW in Resolve using the new settings and the new, just released S-Log LUT. I wanted to see what your experiences are, and see if I am missing something.

I used the recommended settings listed by CD for transcoding the 2K RAW and 4K RAW to Pro-Res. I am on an 2013 iMac with Mavricks OSX.

-Decode Quality Full Res.
-Decode using CinemaDNG Default
-White Balance As Shot - GREYED OUT
-Color Space Rec709 - GREYED OUT
-Gamma Rec709 - GREYED OUT
-Select Highlight Recovery - Off - NOT NEEDED
——————

I got the new S-Log LUT a day early emailed from Andy @ Convergent Design and I have since tested the one posted on the CD website with the same off results.

I just did it as before in Resolve 1) Import the footage into the Media Bin 2) Right click then apply the NEW 3D S-Log LUT. I noticed pretty quickly that the color RED and possibly some other colors were off. But the Reds were really off approaching the pink spectrum.

The STRANGE thing is, the OLD Resolve BMD settings and the OLD LUT works much better on the footage with the new firmware. At least the colors are pretty much right, although they don’t match the 4K2HD (but I would not expect the colors to match).

My question to you guys are:

1) Are you guys just using the OLD Resolve BMD settings and the old S-Log 2 LUT to transcode the new 4K and 2K footage. I have got decent colors with the old BMD settings.

2) Have any of you tried the new DNG settings and the new S-Log LUT. My reds are just completely off and there is this slight magenta tint to everything.

3) Is your 4K2HD looking exactly like your transcoded RAW 4K / 2K RAW clips? Mine are very different. The 4K2HD does look very, very close to the AVCHD S-Logs as CD mentioned it should. Andy @ CD told me that the new Resolve settings should make the RAW files look identical to the 4K2HD.

Take a look at the images I attached. I’m wondering if I am missing a setting or if there is a bug with the new recommended settings and S-Log LUT. On the Dog image, the top row with the OLD BMD settings are more accurate. The bottom dog row is with the new settings and there is a serious magenta shift.

DVXuser uploads the images smaller, so here's links to a larger size if the ones below are too small

www.builtbyugene.com/misc/dog2.jpg


www.builtbyugene.com/misc/Test.jpg

Test.jpg

dog2.jpg
 
Last edited:
I'm wondering if it could be a graphics card thing, because I talked to someone in the know, and he didn't notice any drastic Red color shifts. Or maybe I'm missing a step or something.

Like I said, the 4K RAW looks fine with the old BMD setting and old LUT, just looks off with new settings and new LUT.

My computer is: 2013 iMac, Mavericks, with NVIDIA GeForce GTX 780M 4096 MB

Can someone shoot something colored Red really quick?
 
Hi Gene, I don't think it's a graphic card thing. I have a preview monitor with a Blackmagic Studio Mini Monitor and it looks the same via external or internal monitor. I asked this already yesterday but got no answer.

here's how it looks 4K RAW, recommended settings, no LUT. Not too bad to start from.

4KRAW_noLUT.jpg



New settings, new LUT applied.
newSlogLUT.jpg




previews setting, previews LUT
old_LUT.jpg



I have no idea how to handle the new LUT or what I would need it for?
 
Thanks Clermond, I think I just miss-understood the new Resolve instructions. I don't know Resolve that well, but it looks like you are doing it differently (The right way :) ) and I've been doing it wrong. I was under the impression that the Rec709 was a completely different process.

I'm going to mess around some more. Thanks again.
 
The LUT naming convention looks like FROM_TO. Raw is Linear. So Raw_Slog should convert Raw to Slog, Linear_709 should get Raw to Rec709 etc. Part of the issue is Color Space and Gamma- is there any way to replace with the correct settings? Should be Raw/linear and no Gamma changes vs Rec709, BMD Film, etc. I'm guessing Resolve converts (linear) Raw to the color space and gamma selected, so it should match the LUT you use next. For 5D3 Raw I use Rec709 color space and no LUT.
 
I think I'm missing the 3rd step where you need to add another node (S-Log to Rec709) after applying the new S-Log 2 LUT.

Paul Curtis listed his steps as:

1. Straight CinemaDNG
2. With the CD SLog2 LUT applied
3. With the above Slog applied, then in the next node a Sony SLog to Rec709

When reading the instructions, I thought the S-Log 2 and the Rec 709 part were for two seperate processes, instead of part of the same process. I gotta figure out the node based Resolve system, which I'm not used to.

Thanks again.
 
Hey Mitch,

The new Resolve directions in the OQ7 ReleaseNotes_1.1.105_19Mar2014.pdf are a little bit confusing.

Is it possible to do a clear and concise step by step, kind of like how you guys did the first Resolve Step by Step with the BMD settings back in November. That was really easy to understand for us Resolve boneheads like myself.

Thanks
 
Ideally CD should be able to supply "Camera Metadata" (in the Raw / Color Space pane) and a direct Rec709 matrix/transform or 3D LUT. Going from raw/linear to log makes sense if the goal is to output to a 10-bit, etc. codec (reducing color space) otherwise direct raw/linear to Rec709 makes the most sense.
 
With three people responding that they are reading this as three different methods, clearly we need to write out these instructions better. I'll ask for this to be done.
 
You must log in or register to reply here.
Back
Top