Why can't I resolve deep sky objects?

I have a 12" Meade LX90 just outside Las Vegas. Light pollution is a
problem, but I don't think a major one. I've been trying with no
success to get a clear view of M13, using eyepieces ranging from 40mm
down to 10.4mm. At the lower magnifications, it looks like a
moderately bright star; at higher magnifications, it looks like an out-
of-focus blob that seems very roughly to have the shape of M13 (based
on photos). I cannot resolve even two stars, much less the dozens
that I think should be distinguishable. I'd appreciate any thoughts
or suggestions.

Bob Feduniak
.

Quantcast