the described method works, but using 2 color-lookups is very slow in PS
i would recommend using Affinity Photo , it has OCIO implemented and it works flawlessly
sorry but where did you get the .csp file for PS from?
Forgot to answer you sorry !
Thanks, yes i know affinity has OCIO support but from what i read it has an issue where it bake the icc profile on the output file.
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Hi Liam,
up to now I never exported an image from Affinity Photo with OCIO other than EXR files. And with these I never had any problems. Now I tried to export a JPG and apart form the ODT something else is baked into the image and make it lighter in my case.
Where did you read about this issue? Is this filed as a bug? Do you know this?
Thanks for the information.
Daniel
Thank you Alex. This will help us a lot on our current film (Adipurush)
Behram
hello, reopening the topic with a little bit of a twist 
thank you @alexfry for explaining the workflow in your initial post, very helpful
Although the main problem with limited tool palette in 32bit mode in PS is still on the table and something DMP Artists cannot live with…but that’s another topic…
Please, how would you do this in Photoshop:
import AcesCG EXR and export as AcesCCT 16bit TIFF
?
I know how to do it in other programs, but I’m interested in Photoshop particularly.
I have the OCIO Photoshop Plugin. I’m doing the conversion, but the whole issue is when I want to go from 32bit mode to 16bit - PS always adds sRGB gamma to the step…
I don’t see a way how to force it back to “linear” profile, just so it doesn’t touch the gamma.
I only found, that using Export As PNG, I can say, do not do the sRGB conversion…but that PNG is only 8bit. And even if the image is logarithmic, it is not enough.
Thanks for any tips you might have!
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Hi Martin,
I don’t think you are able to convert an ACEScg EXR file to a ACEScct TIF, because you don’t have access to the colorspace transforms in Photoshop.
Photoshop is just not the tool to do such a conversion in the first place.
I put together a little new article about Photoshop & ACES. Maybe you find something else useful there:
https://www.toodee.de/?p=4996
Best regards
Daniel
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PNG can be 8bpc or 16 bpc but even at 16, you are not having a proper linear scene referred high dynamic range file.
I would not recommend anything else but the openEXR file format (not even .tiff or .hdr).
This.
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Hi Daniel,
yes, this is exactly the workflow we use at the studio
In a flame/nuke/ps environment, we use ACEScct tiffs with a lut in ps and conversions in the 2d packages.
No problem.
What I’m trying to build is a simple way for MP artists to have the ability to do the conversion from ACEScg to ACEScct themselves.
To be more flexible and not rely on 2D guys.
I’ve created a simple Nuke script, with correct unpremult, etc. and it works great, but…
Then you have the problem of licences, where MP guys fight with 2D guys for available licence 
So that’s why I’m trying to find alternative.
Let me describe the steps I do in PS:
- Load the ACEScg EXR - no prob
- Use the OCIO PS plugin and convert the ACEScg to ACEScct - no prob
- Export it that as 16bit tiff or png - and I’m screwed
The problem is, that because I’m still in 32bit mode - even after the conversion to ACEScct - thats just the plugin doing the work, PS has no idea - anytime you want to go from 32bit mode to 16bit mode - PS adds some kind of mapping to it - either srgb gamma, or some version of exposure/hightlights mapping or whatever - it won’t just leave it be!
The only option in a menu I found is under
File - Export - Export As - PNG
here, you have the option to NOT apply the srgb gamma going from 32bit to anything lower
but this png is 8bit
kill me now…
so that’s where I got, if you’d have any suggestions, that would be great
or maybe PS just not the app to do this…but it easily could be
if only they had the option to export a 16bit PNG from that menu - that’s it!
thanks
I am aware of all of that, I described the steps in my reply to TooDee, if you’d like to take a look.
Thanks a lot!
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Hi, thanks for your detailed reply. I still think Photoshop is not the right tool to do the conversion.
Why not asking @MrLixm if he can add a TIFF output option in his tool: PYCO Image Colorspace Converter [Free]
This could be another easy way to convert your EXR ACEScg images to ACEScct TIFFs. Just be always aware of the clipping at 222 in scene linear.
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ou wow, wasn’t aware of that!
@MrLixm I will definitely check that. Take my money!
But I’m not after only a simple conversion, there is also the issue of premultiplied cg renders in ACEScg.
I need to first unpremultiply them and THEN do the conversion from ACEScg to ACEScct…
So they could be comped with a bg in ACEScct in PS.
So it’s not just a single step conversion.
Anyway, I’ll keep digging, thanks a lot!
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Maya 2022 with OCIO 2 does create an other layer of crazyness to all this.
Has someone managed to get a workflow form Maya to Natron or Nuke working?
@oglu can you say more about the trouble you are having with Maya 2022 and Nuke? Maya 2022 can use ocio v2 but also still works with ocio v1 configs. Nuke currently only supports ocio v1. So one possible workflow is to use an ocio v1 config for both. Another workflow is use a v2 config for Maya and a v1 for Nuke.
Heya, could we split this conversation into a separated thread about Maya, Nuke and OCIOv2 (if needed) ? Thanks,
Chris
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Alex,
As a 3D generalist freelancer who is just moving to an ACES workflow I’ve just registered to say a sincere thank you. The previous ACES / Photoshop workflow that was suggested to me - not from this forum of course - was unworkable. This is fantastic. You’ve just saved my professional life with this set up.
Thank you for your generosity and expertise. Where do I send the beer…
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Hi Daniel,
I really love your article but I have a question regarding choosing Rec709 instead of sRGB with the pictures let’s say from the internet (I know there is little difference and not that big), isn’t that more accurate to have the sRGB instead?
Thanks
I’d like to loop back to the question posed by @martin.smekal regarding bringing in a 32-bit ACES linear exr and outputting a 16-bit ACES log tiff. Is there any particular reason this is beyond the capabilities of Photoshop’s HDR tone mapping? Assuming consistent AP1 primaries this could be accomplished with a 1D lookup no?
Hi,
I always write out ACEScc or ACEScct 16-Bit TIFF images from Nuke, load them into Photoshop, do the retouch and go back to Nuke.
As far as I know there are still some functions in PS that are only available in 16-bit INT but not in 32-bit FLOAT mode. I use mostly content aware fill and the patch tool.
So I never thought about loading EXRs in PS and exporting ACESlog TIFFs.
Affinity Photo supports OCIO on MAC and the import/export works flawlessly with ACEScg EXR files.
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