F55: F55 S-Log and S-Gamut

Dave Kincaid

Dave Kincaid

DVXuser Sponsor
One confusing topic in the world of the F55 is the relationship of gamma and color space. While some other cameras default the user to a wide color gamut when log exposure is selected. The F55 can shoot in S-Log while shooting a Rec. 709 (Normal) color gamut. This means that a user can shoot with a log contrast curve but still have saturated color if they want to. When shooting raw with an R5 recorder the color space is S-Gamut and the gamma curve is S-log as well. This means that shooting a compressed codec internally with S-Log and S-Gamut gives one nearly all the color and exposure benefits of raw but with more manageable file size and workflow. I highly recommend that when shooting compressed with SLOG to also enable S-gamut in order to maximize what can be done with exposure and color in post.

Keep in mind that setting S-Gamut will automaticly default your gamma setting to S-Log, however setting S-Log will NOT default your color space to S-Gamut, S-Gamut must be set in the system menu under base settings.

Please comment if you have had experience grading/shooting footage that has LOG exposure and wide color gamut.

Cheers, Dave Kincaid
 
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On the F55 I always shoot in slog with s-gamut turned on and grade it that way, but only because it seems like "more is better". I have not done any specific tests with it on and off to really look for a difference.

What's puzzling about the extended gamut on the F55 and its superior CFA is that it far exceeds what can even be displayed, so to what real benefit is it really?
 
starcentral said:
What's puzzling about the extended gamut on the F55 and its superior CFA is that it far exceeds what can even be displayed, so to what real benefit is it really?
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It means out of gamut, super saturated colors and light sources can get mapped/LUTted back into 709 gracefully without clipping and looking ugly.

Go shoot SGamut and point it at some stage/rock&roll lights that are LED color mixers outputting a really saturated shade. The F5 will clip one of the color channels, and a 55 likely will not. I shot a Peter Murphy show in July with two 55s and an Alexa, I've never seen a camera handle rock&roll stage lighting so gracefully.

Also, color spaces meant for cinema distribution are wider and put the gamut to better use. P3, DCI, XYZ, etc.
 
Benefit for acquisition, makes sense. I always thought about the output and how to show it, but your explanation as usual always makes perfect sense.
 
Don't forget that pro 4K cameras need the additional color space to comply (properly) with Rec2020.
 
Dave Kincaid said:
This means that shooting a compressed codec internally with S-Log and S-Gamut gives one all the color and exposure benefits of raw but with more manageable file size and workflow. I highly recommend that when shooting compressed with SLOG to also enable S-gamut in order to maximize what can be done with exposure and color in post.
Please comment if you have had experience grading/shooting footage that has LOG exposure and wide color gamut.

Cheers, Dave Kincaid
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David;

i am currently gradeing a tv movie shot on F55's to the internal recorder, Slog/SGamut.... I'm working with a Dolby4200 refrence mon, so i can easly see the entire gamut should i chose, but for this show's 709 delivery spec's i don't ;-)

It's very rare that i need the wide gamut when gradeing in P3, a Bollywood feature a i graded a few years ago used the color depth in a few scenes, but not often.. the shows i have on the go currently are 3 tv movies and a feature, none of them call for the use of the wider range of colors on a creative level

One note tho, there is still advantages with a raw workflow, shooting with Slog/Sgamut baked in with exposure & WB spot on is 90% of the way there, but my ablity to recover from sub-optimal settings is far greater if i have raw to adjust

d
 
Dermot said:
David;

i am currently gradeing a tv movie shot on F55's to the internal recorder, Slog/SGamut.... I'm working with a Dolby4200 refrence mon, so i can easly see the entire gamut should i chose, but for this show's 709 delivery spec's i don't ;-)

It's very rare that i need the wide gamut when gradeing in P3, a Bollywood feature a i graded a few years ago used the color depth in a few scenes, but not often.. the shows i have on the go currently are 3 tv movies and a feature, none of them call for the use of the wider range of colors on a creative level

One note tho, there is still advantages with a raw workflow, shooting with Slog/Sgamut baked in with exposure & WB spot on is 90% of the way there, but my ablity to recover from sub-optimal settings is far greater if i have raw to adjust

d
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Dermot,

This is true, raw does give you non-baked in white balance an exposure info. Thanks for sharing some first hand experience.

Dave Kincaid.
 
starcentral said:
Here's a pretty good demo showing how the difference can "appear" in a final grade:

http://vimeo.com/64900919
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Starcentral:

This is a very good representation of the power of ACES for a raw workflow. This illustrates the fact that ACES preserves the tone mapping of the sensor and can yield a final image with a huge amount of highlight detail.

Thanks for sharing.

Dave Kincaid
 
Hi David.

Thanks, I found this whilst searching for ACES workflows as I was looking for a way to really maximize the image quality from the F55. 98% of the time I am shooting slog2/s-gamut so working ACES, or linear space is of great interest to me.
 
As a bonus, Sony raw via ACES and SLog/SGamut via ACES look pretty much identical after processing.

Lyle and I have been corresponding from the beginning on 55/ACES, since we're both not particularly fans of the "Sony look", but realize the camera has the latitude/sensitivity/resolution performance of the Alexa.
 
Small world, I met Lyle on REDUSER when I bought his Anamorphic lens from him and didn't even know he had an F55 until I found this video recently.

I believe there are hidden powers in the F55 and soon hope to unleash them thanks to the many great folks on the interweb who freely share information.
 
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