Full Frame Focus on Alpheratz (Alpha Andromeda)
First test with ED80.
The diffraction pattern caused by the Bahtinov Mask - in focus with central spike centered between the other spikes. This was so effective and precise that I didn't trust it at first, but later in the evening it was evident that the focus achieved by this device was better and easier than using the metrics or freehand in DSLRFocus.
November 22, 2008