ACEScg to PQ w/o being able to monitor

Hey all,

First, I know this isn’t an ideal situation since I can’t monitor a HDR signal at the moment but I wanted to ask all you smarter people out there if the logic is correct. I’ve never been asked to deliver anything in HDR hence why I’ve never tested nor set up a way to monitor.

Now if a comp is done in ACEScg, I feel like you would just use an input transform to go from ACEScg to Rec 2100PQ and call it a day but is that not correct?

Thanks for any guidance.

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this tip from @Slabrie help at all @kyleobley ?

it is correct. (yse a view transform though not a input transform i recon, bur not sure if it makes a difference… PQ by itself is a odd curve that doesnt look good on PQ displays it needs a system gamma boost to look fine, which is what viewTransform should give you)

Although as any display conversions, its a creative one, aces 1.1 in flame really doesnt have the best hdr view transforms.

If you have a iPhone you can see my test here in the youtube app for example , where I compare the sdr Rec709 aces view transform to the rec2100PQ. I then took the rec709 and encapsulated it into a PQ stream so that its PQ but still SDR, so they can be compared side by side.

Make sure you gamma up/down like crazy in SDR to check your comps, every single small issue with litghting and comp will become way more obvious.

Or if you have a modern iPhone and maybe wven a macbook with xdr display you can get reasonable monitoring, just not “live”

Thank you both. I did see that post @TimC and a test export confirmed that, but sadly I didn’t have anything to view it properly.

@finnjaeger I noticed a difference with when playing with the different transform vs “Use Rules”. We currently don’t have any HDR rules setup so a view transform was doing the same as the Input Transform from ACEScg to 2100 PQ. When looking at the scopes, the colors on the vectorscrope changed immensely.

When I specify the view transform as ACES 1.1 HDR-video (1000 nits) the colors don’t shift as much. As this is for a brand’s end tag, the colors are obviously quite important. But I suppose this is what you’re talking about.

I appreciate that I’m shooting in the dark here but does using the ACES 1.1 HDR-video (1000 nits) transform sound right?

should be fine but i would really advice you to get a hdr monitor because else you sre really stabbing in the dark

Great, thanks. And totally agree about the monitor. We have LGs that support it, we just haven’t set anything up to specifically monitor HDR nor done any testing.

yea its not that much fun, fastest is to just throw it on a usb flashdrive and play it back on the TV, you at least get a idea of what you rendered :smiley:

Otherwise with flame triggering hdr mode on the LGs can be difficult , depending on which model you might need to go into some service menus on the LG to set it into PQ mode.

Hmu if you need help on that, ive done hdr monitoring for a while now

Thanks @finnjaeger. We’ve managed to get it working with our Sony grade monitor and then the next step will be playing around with the LGs (C1s). Do you know if those require going into the service menus?