topic Saved image from Corona VFB looks overexposed when ACES OT is reduced (e.g. 0.2) in 3ds Max Forum

Saved image from Corona VFB looks overexposed when ACES OT is reduced (e.g. 0.2)

olesyabobrus — Fri, 25 Jul 2025 10:39:06 GMT

Hi everyone,

I’ve noticed an issue with saving renders from Corona VFB when using a custom ACES OT value.

In Corona VFB, if I set ACES OT = 0.2, the image looks perfect — highlights are nicely compressed, no overexposure.
But when I save the image (PNG/JPG) directly from the VFB, the saved file looks overexposed, as if ACES OT was not applied at all.

When ACES OT = 1.0, the saved image matches the VFB perfectly.
When ACES OT = 0.2, the saved image no longer matches — it looks blown out, not like in the VFB.

Question:
👉Is this expected behavior?
👉Is there a workaround to make the saved image match the VFB when using a custom ACES OT value?
👉Should I use Corona Image Editor or another workflow?

Thanks in advance for any help or clarification!

Re: Saved image from Corona VFB looks overexposed when ACES OT is reduced (e.g. 0.2)

haifeng_yuSEVKN — Tue, 29 Jul 2025 13:06:27 GMT

hello @olesyabobrus, thanks very much for sharing the information.

Please note that Conora renderer is a third party plug-in that is not developed by Autodesk, it would be beneficial to contact Chaos Group for more consultations. They will have a deeper understanding of Corona renderer, as they are the developers behind the tool, making them the most knowledgeable source for insights and technical support. Please allow me to attach the contact information below if you need:

Contact Chaos Group

Thank you!

Re: Saved image from Corona VFB looks overexposed when ACES OT is reduced (e.g. 0.2)

joaquim.moral — Tue, 05 Aug 2025 08:50:02 GMT

Thanks for your support @haifeng_yuSEVKN here!