Sunday, April 19, 2009

Planet imaging - focusing methods

Couple of weeks ago I got my Bahtinov mask. It was laser-cut from approx 3mm thick black plastic sheet (thanks goes to Lauri K).

Purpose of this is to aid focusing, that can be pretty tricky sometimes. Mask is placed in front of C8 corrector cell. Then scope is pointed to bright star. Mask creates a visible diffraction pattern. Image on the webcam is followed, and focusing adjusted at the same time. When "line in the middle" crosses the intersection of "X-figure", focusing is correct. I was really suprised how simple and effective this tool is...