Raw Therapee Aces AP1 profile changers when saved.


I have been trying to save my images as aces CG (linear AP1)

The images look correct in the viewport, but when I save them as 16 bit tiffs, they look totally different and don’t look like I want them to if I transform them back to DCI-p3 later.

I have trued with using a custom profile pointing to a RTv2_ACES-ap1.icc

also setting output to RTv4_ACES-AP1 and setting gamma to 1 and slope to 12.92 ( i have no id what the slope thing means.

Left vieuwport Right After Save

It is like the gamma is changed again withoput me telling the program to do so.

Looks like the old Windows Photo viewer; IIRC it will use a display profile. If so, that might be TRC-ing the data up to the display, look for that and turn it off if so.

Also, make sure it’s the ACES profile that is both being used to transform the data on output, and being embedded in the output.

I’m pretty sure it’s some color management mechanism, just have to tease it apart…


What I’m trying to do is just save the raw as aces-CG.
I have no clue what I’m doing, and nothing seems to work.

If I select ap 1 in working profile and output profile and set gamma to 1.

The fact that the gamma selected on the working profile effects the output image the way that it does make me think it’s not just the profile used to do the corrections.

To avoid weird Photo viewer obfuscation.
If I try to change the tiff back to sRGB in resolve, I get the following image.


Post your exported image here, just drag it to a reply. I want to see 1) what profile is embedded and 2) how the image is correspondingly encoded.

First of all, why do you want to output to ACES? You say you don’t know what you’re doing, so ehm, why?
Secondly, RawTherapee uses a linear pipeline for the most part. The working profile you select, only determines the color primaries.
Thirdly, the available output profiles always contain an sRGB tone curve (gamma encoding, so you will). Unless you create a linear profile of your own, you will not get linearly encoded data out of RT.

Hope that helps?

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So, I just read the RT Color Management page (disclaimer: I don’t use RT), and I assume you’re using the ICC Profile Creator to make the ACES profile you want. In that tool, you can either 1) select a preset TRC, or 2) craft a custom one with the gamma and slope sliders. Set the preset to linear_g1.0 and slide the sliders all the way to the left, don’t want them in play.

If you’re not doing (creating a new ACES profile) this you need to, as the included RT profiles apparently have TRCs with gamma=2.4 and slope 12.92. Don’t want that in your output profile if you want so-called “linear gamma”…

Edit: do what @Thanatomanic says…

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Thank you all very much.

If I Understand everything correctly, it seems that if I use an ACES-CG.icc profile directly, everything Wil just do what I want.

And just the ap1 profile on its own is not enough.

The ICC colour profiles for aces CG seem to b hidden very well on purpose.
If annyone can point me to an icc profile for aces 1.2 or 1.3 that whould b awsome.

I wil make one for now hope that one works.

(I need aces CG for 3d VFX compositing)

I have created an icc profile,
Can anyone take the time to be so kind to tell me how to add it so Raw Therapee recognizes it ?

EDIT: its prolly adding a link to the file to C:\Windows\System32\spool\drivers\color

If u hit this,
Go look at this post,

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