Author Topic: Legality of S-log and Alexa log in MLV app  (Read 684 times)

franekyvp

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Legality of S-log and Alexa log in MLV app
« on: August 25, 2022, 02:51:40 PM »
Hi!
I just started using Magic Lantern and I wanted to convert my MLV files through MLVapp. In the app there are Sony and Arri logs to choose. I know it's a stupid question, but is it "technically" legal? Where are these presets from? Are they really from Sony/Arri or are they just very similar?
Thanks!

ilia3101

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Re: Legality of S-log and Alexa log in MLV app
« Reply #1 on: August 26, 2022, 10:29:15 PM »
They are just encodings defined by a curve and a matrix, freely available in white papers from most manufacturers (except shitty ones).

Some examples:
https://dl.fujifilm-x.com/support/lut/F-Log_DataSheet_E_Ver.1.0.pdf
https://pro.sony/s3/cms-static-content/uploadfile/06/1237494271406.pdf
https://www.arri.com/resource/blob/31918/66f56e6abb6e5b6553929edf9aa7483e/2017-03-alexa-logc-curve-in-vfx-data.pdf

How MLV App implements them:
https://github.com/ilia3101/MLV-App/blob/master/src/processing/image_profiles.c

There's nothing illegal about encoding your footage to interoperate with a LUT or a grading tool ;)

Quote
Are they really from Sony/Arri or are they just very similar?

You'll never get the same output from these cameras as you will from a Sony or an Arri, the sensors are different, and processed differently before it even gets to the log. But it's probably close enough.