sRGB to rec709

[Grant]

Hi All!

I’ve received a grade that Flame tags ‘from file or header’ as sRGB. I was expecting rec709. I don’t have the chance to speak to the colourist. Now I’m chasing my tail trying to stop gamma shifts from occurring at later stages in the pipeline.

Can u convert sRGB to rec709 inside Flame without getting a colour shift? (If I just tag it as 709 or unknown, there’s no shift but it all goes wrong at the encoding stage)

Cheers!

Grant

[randy]

Nah ignore that tag. You need to tell it what it is. Flame doesn’t “sense” color spaces.

[Grant]

Arrrghh! I let the tag lead me off the track

I’m getting a tiny shift of the mac desktop - making me think the flame tag was causing it.

When I re-import to flame the shift is gone

Moral of the story… Don’t trust the mac desktop!

Thanks Randy🎉

[randy]

Because you are eventually going to want to dive in, it’s this kinda stuff that you are experiencing.

Scripts to change QT NCLC tag within Flame

With all the discussion lately over Quicktimes and NCLC tags lately I wanted to be able to change the color tags within Flame as a stopgap measure until ADSK gives us the ability to do so. I hope some of you find it helpful. Media Hub & NCLC v0.3 script update There are two scripts: nclc.py (Acts as the middleman to send things to AMCDX) nclc_mediahub_tag.py (Media Hub Hook) How To Install: Download AMCDX Video Patcher for Mac or Linux Modify nclc.py to point to the correct locatio…

The short answer is, almost every OS and browse and mobile device and video player handle gamma and NCLC tags differently.

As the WOPR A.K.A “Joshua” comes to learn after almost destroying the planet in “War Games” (1985), “The only winning move is not to play.”

[finnjaeger]

yea check the nclc tags in quicktime (cmd+i) feel like flame is correctly importing it as srgb because the colorists tagged that on export. its probably 1-13-1.

Sounds like half-baked knowledge from the colorist, I heard some are setting their timeline colorspace which changes the metadata tag on export to sRGB because they do web-delivery , its not that simple sadly but its one of those “how to fix gamma shift” youtube videos…

anyhow that tag will get removed once uploaded or when send to broadcast.

What you can do if you just want peace is to:

1. treat it like everything else, import as 709 or untagged or whatever colormanagement preset you use like always and then change the metadata after rendering using amcdxPatcher or ffmpeg.

2. use aces and import it as output-sRGB and export with output-srgb “lut” (in the export settings lut-> view transform-> Aces-SDR->sRGB. this should tag the quicktime file as sRGB(1-13-1) . then it will match again in quicktime.

3. hunt down the colorist

[Grant]

Finn. This is great! I’ll be checking this out later today. Thanks!