Last night was the first time I saw the Airy disc and concentric circles as viewed through a 9mm Nagler in a 13.1 inch newton. I had tried before but I guess the seeing was poor. I was kind of thrilling, see those tight concentric circles for the first time. But the scope was way out of collimation as the center was skewed to the left. I have lost the link to a website that shows photos of airy disc, in and out of focus / collimation. Does someone know of a good site. Thanks in advance.
David Roberts
David Roberts
David Roberts
David Roberts
