HDR workflow tips?

My first time with HDR. I found and will watch the Andrew Archer video from 2021 in a moment!

P3PQ1000nit Dolby with SDR trims. Is this a situation where i would work in camera log → ACES in Flame, LUT out 709 for WIPS, then color house, and then apply graphics, etc at the end in their respective outputs?

I do have an Apple XDR to see HDR in Flame

@aaronneitz - reach out to @AdamArcher directly.
Lovely human.
Just adjust for the Australian time shift - he lives in the future…

1 Like

Hi @aaronneitz and thanks for your kind words @philm

Am I right in thinking that you are working on ungraded shots?

2 Likes

We have a call with the color house tomorrow - no workflow has been established yet. I’m just getting my ducks in a row!

Typically because of nature of the work (music video) I’d prefer to work on colored plates for expediency. No idea of the scope of the work but I just assume boring set cleanup and face beauty.

1 Like

Ok, that makes sense. I tend to do VFX on ungraded material because it gives the director/DOP/colourist the latitude to change their minds. It can also help when there are multiple colourspace deliverables to be made, theatrical DCP in XYZ, Home Ent in HDR, Home Ent in SDR, etc; If it is a music video though, I doubt you will need to account for theatrical. Out of interest, do you know how they are deriving their SDR? Are they doing a Dolby Vision workflow, are they grading in ACES and simply doing an output transform, are they planning on doing a SDR grade from the HDR source, or are they doing a new grade from the original source (yuck, not sure why anyone would do that but I know it happens a bit by ‘colourists’ who don’t really know what they are doing).

Unfortunately, the way the colour house is doing the grade will dictate the best workflow. I can breakdown the 3 most likely though.

If ungraded, either work in the native log colourspace or work in ACES using exrs. Do NOT ever get Log provided footage in exrs as this is destructive. I’m all about working in ACES, transporting it in AP0 ACES2065-1, working in ACEScg, then delivering back as ACES AP0. The beauty of ACES is you can view it however you want at your end, just view through the output transform that suits your monitor. There are plenty of good resources on Logik for working in ACES so no need to elaborate. Working in LOG is equally valid, but try to work uncompressed or with minimal compression in a bare minimum of a 12bit codec. Definitely DO NOT work using any 10bit codecs as this will destroy the image when grading HDR then deriving SDR from that.

If working on graded images, hopefully they are grading in ACES. If so, get the graded pictures sent in ACES AP0 in exrs, do your work once again in ACEScg, viewing through whatever output transform suits your monitor, then send back to them in ACES AP0. The beauty of ACES workflows is you can pretty much work in any manner on whatever system and tailor your output transform to whatever display you have got at hand. The HDR P3D65PQ, Theatrical P3CDI or P3D65 at gamma 2.6 and SDR all translate well from an ACES grade. If you are working on HDR graded pictures this would be my recommended workflow.

If they want to send you the HDR grade in P3D65PQ that is also fine. Once again, ensure that you are working in a minimum of a 12bit codec. As long as you tag it correctly in Flame, then you should be able to display it correctly. If you only have SDR monitoring, a quick trick is to add a Dolby HDR node and do an analysis and that will give you a good represenation in SDR. If you have an XDR display, it should do a decent job of displaying the P3D65PQ accurately anyway, just make sure you are viewing it correctly in Flame. Is your GUI the XDR though or are you using it as a broadcast monitor?

If you need to create approval files from the HDR, you will need to know how they will be looked at. If they have a decent HDR display (such as an iPad Pro) then you can just send them the graded HDR. If they only have a SDR then I would suggest using the Dolby HDR tools within Flame to analyse the shot and create the SDR deliverable using that. ACES is also an option for this using Colour Management within Flame.

Feel free to contact me directly once you have chatted to the colour house. The way they want to grade the music video will dictate the way you work on the shots. Personally, I would always prefer to do the compositing on the ungraded but working on graded HDR images is equally valid.

10 Likes

Awesome awesome! Thank you for the knowledge bomb!

1 Like

Looks like we’ll work in camera log with a show LUT, basic TV workflow, and send final timelines for color in HDR and they’ll also render SDR trims. Then slap graphics and deliverables back in Flame.

Your youtube live was super helpful! Cheers!

2 Likes

@AdamArcher - for the win

1 Like

That sounds like a good way to work to me. Thanks for sharing, always good to know it worked out.

If anything comes up feel free to message me.

1 Like

Do I understand correctly: if they have graded the video, they can give us P3PQ Prores, and we can notch their Dolby XML in Flame. So if I do VFX, or repo, or copy/paste a shot in a cutdown, that XML will safely retain their SDR trim data?

(client wants to approve grade now, we’re full steam doing cleanup in camera log otherwise. There are concerns on tight turnaround)

When you import the xml it will be already notched and behaves just like any other clip, copy/paste move, whatever as long as it stays paired to the graded segment below.
One thing to look out for, there is a bug where the colour management doesn’t stick on export, so add a track CM effect above the hdr(xml) track and tag it as 709.
It’ll all make sense when you see it.

1 Like

Thanks, we got conflicting info from color about notched XMLs

Are they giving you graded ProRes now to work on or is that just a reference? What flavour ProRes have they given you?

If you are working on Log, I’m assuming you are just going to send that back to the colour house and they will apply the grade at their end?

Right now we’re working log with HDR and SDR LUTs for WIP output. Working off camera RAW slog3. I’m concerned because if I repo a shot color said “we graded with power windows for the un-repoed shot”. Stuff like that with an insane turnaround including social resizes, etc…

I think it best for us to march on in log.

Totally march on in log. Only apply any repos to your WIP files, and send reference for colour to match when they render the grade (or do it post grade if you’re finishing). Work in camera original resolution/aspect too or that might cause issues. (if you scale down at the same aspect as a working resolution that is usually ok).

You sound like you are all across it anyway but reach out if needed.

1 Like

OK gurus. So I have an AE guy who needs to melt my HDR picture into some animation he’s done.

I provided him with st2084(pq) prores, a rec 709 reference made by color, and a 2084>ACEScg flame conversion. They’re all looking wrong to him in AE. Anyone have any tips on how to guide them?

Apparently OCIO is new in AE and full of options.

Obvs he’s asking AE forums. But.

describe your conversion to ACEScg and delivery mechanism.
i don’t have access to a macos computer for at least another four hours so I can’t see, but my tests with AP1 and AP0 seem consistent with flame.

things to check on the after effects side are bit depth and color management.

i did these checks with @dave who might have more insight since he works on a mac with flame and ae installed.

this is how we tested the after effects round trip form LOGIK-PROJEKT.

2084 prores into flame, tagged, > Clr Mgmt > from source to acescg. Export EXR.

and does your conversion also map to rec709 predictably?
does it match the colored version?

i’m not sure why you are delivering an ACEScg version and a rec709 version.

Is it so that the AE artist can see that your ACEScg should look like the Rec709 version?

Can you reverse out from the Rec709 to ACEScg?

Is everything bidirectionally color compatible in flame?

@aaronneitz - i sent you a zoom link in this forum DM chat thingy

In Flame it all maps back and forth fine. 2084 > 709, 2084 > aces > 2084. 2084 > 709 > 2084 looks fine

AE suggests ACEScg so we have a universal color space, I would translate back to 2084 on ingest.

1 Like