I guess you don't hunt under low light conditiions.
I guess you also don't figure anyone else does either.
That would rule out facing into a setting/rising sun too.
As far as Parallax (parilax for some folks). That generally isn't going to affect you seeing a thumb sized branch at 30 yards.
"A high dollar scope on a crossbow is like a precision guidance system on a wiffle bat." For some people I just became convinced that this is a true statement.
