reard black spot on glass

hi. when i was rendering a glass i get a ugly black spot at the top
i donth now if it comes by the size of the background but hope you can help me


Increase the depth, by default it should be 2, try 4 instead.

the depth of what pls?

oh sry i found it
the depth of the mirror
and it works
thx for the reply

Last field at the bottom of the screen shot.


yes i found it
it looks great now
thx again