Renders darken when focal distance lowers

[michae]

Hi I am curious to know if there is a physical reason behind this or just a bug. I have a camera and a distance tool with 2 locators, the distance between the locators is driving the focal distance of my physical camera. When my focal distance gets lowered to a certain point my renders start to darken.

[pg1]

turn off vignette in the camera, like a real world camera lower focal distance equals more vignette

[LarsSonparsson]

All I can say is, that it's not a bug, but kinda way how real camera works.
I don't know the explanation behind it. There have been thread about it earlier, but I didn't find it.

Sorry for non informative reply. Just wanted to confirm that it's not a bug.

[simmsimaging]

I had this with Max before and still do sometimes. I consider it a bug though, it is not expected behavior from a real lens in my experience.