Shadows problem

[Arian Shamil]

Hi to everybody...
When I use a background different from white i've a shadow problem...
The shadow is not "graduated" but is like in low resolution.....the shadows are composed from just 6,7 type of black and grey....it seems like a low color depth...
I hope you can understand my problem....i've attached an image to understand the problem...
Excuse me so much for my bad english...

[Arian Shamil]

Hi...my problem...is like a color depth problem but only shadow are involved....when i use a dark background my shadow appear like an 8bit image...is that normal?
For example....my shadow appear like the 8bit shadow image that i've attached....

[edwardo]

Iv had this problem before.

Have you tried using a 16 bit tiff background instead?

[Arian Shamil]

Thanks a lot to have replied to me.
Yeah, i've tried...i've tried all the option but it's always the same....I've tried JPG, PNG, TIFF and TIFF 32 bit...but i've always this problem....i really can't understand what could be the problem...also because i've the problem only on the background/floor shadow...

[edwardo]

ehhhh, have you tried adding a ground plane (geometry)?

other than that i dunno?