can't collimate lightbridge

[sejanus (Gavin)]

There's a thought, although it was a bit soft even at 32mm which is pretty low mag. But yep thats possible, unfortunately it's my only scope at moment so i can't compare it side by side to another.

[Gargoyle_Steve (Steve)]

You mentioned adjusting the secndary mirror back up there but didn't mention adjusting the primary afterwards, and the issue you talked about regards the return laser dot coming back "off centre" - that's primary adjustment.

If you've already tweaked the primary as well then please disregard what I've said. Hope you get it sorted out pronto.

[Roger Davis]

Do your final collimation on a star (obvious I know, but I thought I'd better state it). Whilst you are at it you can check the quality of your optics with a Ronchi screen held on the top of the focuser (no eyepiece) and rack the focuser in and out slightly. If the mirror is a perfect parabola you should see dead straight lines from one side of the mirror to the other. HOWEVER, should you see slight distortions to the lines it doesn't mean that your mirror is bad, just that there may be a turned down edge or a slight zonal error. Check out Dick Suiter's book: Star Testing Astronomical Telescopes
Check that your spider vanes are square onto the optical axis as well!