Sunday, October 21, 2018

Amazing how many "failures" clean up nicely after some processing.  Pretty sure this was with a 25mm eyepiece projection; 1/80th; ISO 400
1/320th; ISO-400; prime focus

As the magnification increases, critical focus gets more important.  This was with a 12.5mm eyepiece; 1/15th sec.; ISO-100.
There are several strategies for improving critical focus: the Hartmann Mask and its variant, the Scheiner Mask.  There is also a new device, invented recently, the Bahtinov Mask.  This picture will tell you why few amateurs make them.

No comments: