FS5: If I shoot CDNG RAW on the FS5, is it shooting with an SLOG-2 gamma?

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Kobe24Life

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Since to get raw out of the FS5 you have to go through PP7 which is SLOG2.

The problem with this for me is I much rather prefer SLOG3 since I'm shooting a darker scene and SLOG3 gives a bit more detail in those lower light areas.


I also read that you can chose which gamma to use AFTER you shoot the footage. But this is weird to me because what am I exposing for? what picture profile?
 
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It seems like SLO3 has a bit more data in the shadows based on this and I'm shooting something that is going to have a lot of shadows that's why I'm wondering if I can get RAW with SLOG3 gamma from the FS5. Correct me if I'm wrong but I think I'd have the option later on debayer to chose my own gamma, or is it SLOG2 defaulted since that's the picture profile reccomended for RAW on the FS5, just a bit confusing.
 
If you are truly shooting RAW, then there is no S-LOG2 vs. S-LOG3 decision to be made at the time of shooting. When I shoot Sony RAW with my FS7/R5 or F55/R7 I can decide in Resolve whether to decode it as S-LOG2 or S-LOG3. I do not remember what options are available to you for the FS5, especially without knowing what external recorder and codec you are using. But if it is truly "RAW" then there should be no S-LOG decisions to be made at the time of shooting. But the point of my first post was just to answer your question about exposure -- it is the same no matter whether you are shooting RAW, S-LOG2 or S-LOG3. That information alone should be helpful.
 
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Doug Jensen said:
If you are truly shooting RAW, then there is no S-LOG2 vs. S-LOG3 decision to be made at the time of shooting. When I shoot Sony RAW with my FS7/R5 or F55/R7 I can decide in Resolve whether to decode it as S-LOG2 or S-LOG3. I do not remember what options are available to you for the FS5, especially without knowing what external recorder and codec you are using. But if it is truly "RAW" then there should be no S-LOG decisions to be made at the time of shooting. But the point of my first post was just to answer your question about exposure -- it is the same no matter whether you are shooting RAW, S-LOG2 or S-LOG3. That information alone should be helpful.
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I thought Sony applies a little curve as there is only 12bits coming out of the "raw" from the FS5?

While you can do pure linear raw with the 16bits raw you get from the F5/F55
 
With Shogun Inferno, taking the 12-bit linear RAW from the FS7's XDCA extension RAW SDI output allows to either preserve RAW (in the form of 12bit CDNG), or apply Shogun's own S-log2 or S-log3 (along with S-Gamut or S-Gamut3.Cine respectively) and encode the 12-bit linear RAW data from the FS7 sensor into 10-bit Prores (up to HQ) or DNxHR (up to HQX). Either of those options provides definitely much higher Picture Quality than internally recorded XAVC-I. Hope this helps

Piotr
 
Kobe24Life said:
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It seems like SLO3 has a bit more data in the shadows based on this and I'm shooting something that is going to have a lot of shadows that's why I'm wondering if I can get RAW with SLOG3 gamma from the FS5. Correct me if I'm wrong but I think I'd have the option later on debayer to chose my own gamma, or is it SLOG2 defaulted since that's the picture profile reccomended for RAW on the FS5, just a bit confusing.
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Look on the chart at the line for 94% IRE recording level. With S-Log3 the FS5 cannot write above this level because it is a 16 stop curve applied to a 14 stop sensor. But at that 94% level S-Log2 still has a full stop of recording range before it peaks at 106%. You could open up the iris 1-stop to give more exposure to the shadows (reducing noise) and with S-Log2 still be at about the same IRE recording level as S-Log3. It has been said that S-Log3 can be noisy in the shadows. This is because the same level of actual scene brightness (along with noise) is recorded at a higher IRE level for the range between +2 and -6 stops (relative to middle gray).

So why don't we do this? Because there is no free lunch. Look at the chart again, this time at scene brightness level of -8 stops. At that point, the IRE level for S-Log2 and S-Log3 are the same. There is no difference in the actual light sensitivity between the two gamma curves because that is a function of the sensor not the curve. Opening up the iris 1-stop for S-Log2 moves up everything in the scene by 1 stop and fills the IRE gap between 94% and 106% but it also pushes out everything that was already there so you don't gain actual dynamic range. It's an option of trading away some scene highlight detail for less noise in the shadows with the understanding that you don't change overall dynamic range with S-Log2 nor is shadow detail gained by S-Log3.
 
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