pls help me: DOF enabled VrayCamera render darker

[pixela]

Hello,
I have this problem that I resumed in the title.
Below I attach 2 images, with DOF-enabled, and DOF-disabled from VrayCamera.
Both images have same light and cemra settings except enabiling DOF.

Is this a bug?
Or is it supposed to be like this? If so, can anyone explain me the reason?

Thanks in advance.

[pg1]

turn off vignette in your camera

[pixela]

Thank you very much for your reply.
I tried this and it works

But why does vignette has this darkeninig effect on overall render frame when DOF is enabled ? Isn't vignette supposed to be darkenining of corners?

Thanks again.

[pg1]

Isn't vignette supposed to be darkening of corners?

yes this is correct vignetting is a darkening of the corners but it is affected (like a real camera) by aperture

So you are reducing your f-stop no. to get stronger DOF and then balancing your ISO and shutter speed to keep the same exposure the same

When you reduce your f-stop you are by default increasing your vignette

[pixela]

Thanks you very much.