Vrayphysical camera Auto Exposure

[vjaramillo]

I have a quick questions regarding the auto exposure feature. I've noticed while rendering interiors that when the camera is pointing at the outside, the interior is dark but the exterior HDRi is exposed correctly. When I point the camera target towards the interior space, all is exposed properly. Wouldn't auto exposure try to balance both out both dark and light areas to give you an overall balanced image?

[vjaramillo]

Same camera just changed target.

[Martin.Minev]

The following behavior is expected in cases like this, when you are having a very high contrast scene. My advice is to render the camera that shows mostly the interior. Then transfer the exposure to the camera ( or all cameras ) in the scene. This will set the ISO values accordingly
and you can manually adjust the exposure after that. You can restore the highlights in the VFB or in post-production, when you are saving in a V-Ray raw image file format. In V-Ray Next Update 1 you can also save the color corrections in the final image as EXR or VRIMG.
To do that you have to enable the Save VFB color corrections to RGB channel option in the save dialog.

Best Regards,
Martin Minev
Chaos Group Support

[vlado]

In addition to what Martin mentioned, one thing that may help is that the auto-exposure only takes into account areas with non-zero alpha. So if you make sure that the background has zero alpha (f.e. from the V-Ray object properties), V-Ray will ignore it when computing the auto-exposure.

Best regards,
Vlado

[vjaramillo]

Coo...Thanks guys.