It does not seem like much LUT support exists for SLog

Mike Krumlauf

Mike Krumlauf

Award Winning Filmmaker
...as in the SLog 1 curve in the 23 and 35. There are plenty of things out there for Slog 2 and 3.. but not much for the first SLog.

Why dont we grow a list of LUTs and steps people are doing with their F23 and 35 in terms of grading when using Slog???
 
That's a good idea. I have either been using ACES or the colorspace transform suggested by rbirmbaum. Impulz has luts for the original slog

Ultimately what I have decided to do and am almost complete with is making a lut that goes from slog/sgamut to arri wide/logc. Plenty of options out there once that conversation is done.
 
I would love a mathematically correct SLog to LogC conversion LUT. That would really open the doors up. I could accurately use LogC presets in Film Convert with the F23 which I think would be beautiful if done correctly... currently it crushes the blacks way to much!
 
That's the plan, mine would be mathematically correct since I am using the technical papers to do the conversion and generate the lut. I am also accounting for the gamut change. I am working the bugs out now and will share when and if it all is working correctly.
 
Mike Krumlauf said:
I would love a mathematically correct SLog to LogC conversion LUT. That would really open the doors up. I could accurately use LogC presets in Film Convert with the F23 which I think would be beautiful if done correctly... currently it crushes the blacks way to much!
Click to expand...

If you're using Adobe Premiere Pro, try the new FilmConvert Nitrate and set the Print Film slider to 0 (e.g. full Cineon Log, very similar to LogC)
 
John Parker said:
If you're using Adobe Premiere Pro, try the new FilmConvert Nitrate and set the Print Film slider to 0 (e.g. full Cineon Log, very similar to LogC)
Click to expand...

Im old school son! Using Final Cut Pro 7 on my 2008 Mac Pro :b. I personally hate Adobe. just me... (dont judge) :b

I do own Film Convert for fcp 7 though and love it.
 
For the record I currently shoot in SLOG/SGam and have the SRPC1 dock hooked into the Panavision GDP Box which is fed into my Mac pro Via Kona 3 card. I use a SLog to Panalog conversion lut in the box and create my own grade in the box using the pre and post gamma functions.

Given there is more shadow and highlight information in SLog, converting to Panalog works perfectly. Would have sucked if Panalog was more sensitive than SLog, dont know how i could have properly converted that. (thanks sony :b)
 
Mike Krumlauf said:
I would love a mathematically correct SLog to LogC conversion LUT.
Click to expand...
There is nothing mathematically correct about LUTs they are interpolators.
A mathematically correct colorspace transform can be found in professional color grading software like DaVinci Resolve.
 
Mike Krumlauf said:
I would love a mathematically correct SLog to LogC conversion LUT. That would really open the doors up. I could accurately use LogC presets in Film Convert with the F23 which I think would be beautiful if done correctly... currently it crushes the blacks way to much!
Click to expand...

Davinci Resolve 15's Colour Space Transform tool is pretty remarkable. I used it to match a Sony F3 B-cam to our Alexa A-cam on a series a while ago, and it worked a treat.

Very hard to distinguish which camera was which.
 
Grug said:
Davinci Resolve 15's Colour Space Transform tool is pretty remarkable. I used it to match a Sony F3 B-cam to our Alexa A-cam on a series a while ago, and it worked a treat.

Very hard to distinguish which camera was which.
Click to expand...

This is the resolve feature where you shoot a color chart and have resolve match the shots?
 
No it's an ofx effect that converts one colorspace to another. You can for example convert slog into slog3 or logc. I was making a lut to do this until I realized the colorspace transform could already do it. I have been experimenting with it and have been getting good results so far.
 
Use colorspace transforms and just say no to LUTs, especially to LUTs that claim to do things that are too good to be true!
 
So in davinci then... if i have material that was shot in S Log/ S Gam and I am finalizing in Rec709, how would my project settings look so when i do color space transforms i am viewing things correctly and exporting correctly?
 
Mike Krumlauf said:
So in davinci then... if i have material that was shot in S Log/ S Gam and I am finalizing in Rec709, how would my project settings look so when i do color space transforms i am viewing things correctly and exporting correctly?
Click to expand...
Input colorspace: S Log
Timeline colorspace: To you liking, some people like to grade Rec709 like controls others like Log controls
Output colorspace: Rec709

Optionally gamut/tone map timeline to output gamut/gamma.
 
From my experience so far with the F35 setting the camera to F900 color space produces better colors than SGamut (and then SGamut to Rec709 Transform in Resolve.)
 
Cary Knoop said:
There is nothing mathematically correct about LUTs they are interpolators.
Click to expand...

Probably for another thread. I dont think this is correct?

A look up table

1=banana
2=orange
3=grape

Input value
213
With lut applied
oragne, banana, grape
Out put value
213
Mathematically Lossles.
Input = Output exactly

A second LUT
1=banana
2=orange
3= or >3 = grape

Input
432

Output
332

This second LUT is lossy as the 3 and the 4 are compressed to being 3 and data is lost.

LUTs dont have to be destructive ?
 
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