Colorspace clipping using add blend modes in OCIO v25.2.2

[NRowe]

Hi,

Just upgraded to 25.2.2 and I am having a strange issue with adding layers its like it randomly clips or switches color space from one frame to the next. Only started happening after upgrading AE and NVIDIA.

The screenshots are from the same project just different frames, as you will see it also affects the scopes. Only effect used is 'Fast Box Blur'

Switching to 'Software Only' fixes the issue

[NRowe]

Here is a better representation on the scopes with the signal clamped. Its clearly clipping on 1, this happens randomly as I scrub the timeline.

[nishu_kush]

Thanks for reaching out.

Do you mind sharing your system specifications and details of the media? If possible, please share a sample media and After Effects project file for testing. Feel free to share via DM if you do not want to share publicly.

Looking forward to your response.

Thanks,
Nishu

[NRowe]

Thanks Nishu,

My system Spec

Processor 12th Gen Intel(R) Core(TM) i9-12900K 3.20 GHz
Installed RAM 64.0 GB (63.7 GB usable)
Edition Windows 11 Home
Version 24H2

GeForce RTX 3080
NVIDIA Studio 576.02

I will DM you the AE file and asset

Thanks again,

Neil

[nishu_kush]

Thanks for sharing the files and details. I am able to reproduce the issue on my end. However, it's different on my end. The values are clipped the whole time as shown in your screenshot at the bottom. The Scope looks not clipped on specific frame if I change the value of the Fast blur on any layer. If I disable the Fast Blur, it seems to be working fine. I've filed a bug for further investigation. Thanks for reporting.

Thanks,
Nishu

[NRowe]

Thanks Nishu

Good to know its not just me!

[J5DDE]

I am working with After Effects 25.2.2, Color Engine OCIO ACES 1.3 Studio v1.0, 32bpc

I have worked with the same color management configuration since ACES was available a few versions ago (two years ago I think). 

However, for the past two weeks I have had trouble with the white levels. As soon as I start blending some layers the RGB values start clipping at 1.0.

When I check each layer isolating them, the levels are correct (going over 1 when needed), but when I add the layers, they get trimmed at 1.

See below before (L) and after (R) I activate the layer in "Add" mode.

I'm pretty sure it's a bug, since it has never happened before.

I'll probably go back to some previous After Effects version, but I wanted to notify it so it can get fixed soon.

[J5DDE]

Just to be clear, I am not adding any effect that is meant for 16bcp to the footage. I have worked with 32bcp for many years now and with the ACES engine in After Effects for the past two, so I am aware that adding a 16bpc effect would cause the same result. But I am getting the clipping just by Adding a simple solid layer mask.

[nishu_kush]

Thanks for writing in.

This issue has been marked as a bug. Merging this thread with the parent thread.

Thanks,
Nishu

[J5DDE]

Thank you Nishu!

[David Emmenlauer]

I'm working on a project for TV with OCIO color management, ACES 1.3 Studio 1.0 in ACES2065-1. When I render out Clips, and this is also visible in preview renderings in the viewer, the image is flickering between the full dynamic range and a cutoff at 80% brightness. When I deactivate Mercury GPU Acceleration and render Mercury Software only, the image is fine.

This occured on my M1 Macbook Pro 64GB, so I switched to my Windows 10 PC with two NVIDIA 4090 cards and the issue is the same! I tried deactivating hardware accelerated decoding and encoding which did not help. I also tried deactivating different layers and effects in the comps without any luck. I also tried to switch the project from ACES2065-1 to ACEScg, but the problem persisted. The only thing that resolves the problem is rendering Software only, but since I have effects that need the GPU Acceleration to work, I need to resolve this issue. Sometimes, when I canged a value like the opacity of a layer, the frame suddenly rendered fine, but this just meant, that the flickering occured on some other frame.

I use After Effects 25.2.2 (Build 2). I'm working mostly with OpenEXR Sequences in ACES2065-1 and additional material like JPGs or Illustrator Logos which are converted from sRGB to ACES2065-1. Perhaps also important, I have the plugin "mask prompter" installed and also used it in the project, but "mask prompter" is not connected to the issue, compositions that don't use "mask prompter" are also affected. 

Here are Screenshots that illustrate the issue, see the color shift in the logo on the top left corner of the monitorscreen, where it is most apparent:

You can watch the whole clips here, click links or paste links into the browser:

data.fabelwerk.de/BHK_0140_v01_GPU_Acceleration.mp4

data.fabelwerk.de/BHK_0140_v01_Software_only.mp4

Please help me find a solution to this issue! Thanks!!

Best, David

[nishu_kush]

Hi David,

Thanks for writing in. This issue has been filed as a bug and is under investigation. I am merging your thread with the main thread.

Thanks,
Nishu

[NRowe]

Any updates on this, is a fix coming anytime soon?

[David Emmenlauer]

Hello Adobe, I also would like to know if we can expect an update / fix soon as I am really depending on a reliable color workflow. By the way, I found out by accident, if I export a video in sRGB and import it again, when I comp this reimported sRGB Video, the whites are way too high and totally blown out, way more than normal sRGB footage. Perhaps this helps resolve the issue. Also, color correction tools to manage overbrights would be very much appreciated in ACES, with the tools we have, it is very difficult to tame some hi-key colors and whites. Thanks!