Just collimated my GSO lazer collimator (thanks for the tips Alex
) and at 4 metres it was tracing a 50mm diameter circle on the target wall. That can't have been good and after 10 minutes playing with the tiny allen screws I got it down to a tenth of that. Collimation is so important in fast Dobs like mine so I'll see if it's made a noticeable difference tonight. I also tightened the beam while I was at it so all's ready for tonight's Tele Vue eyepiece christenings. Not a cloud in the sky as well.
Pic of my 2 minute collimating rig.
http://i669.photobucket.com/albums/v...f/SAM_1878.jpg