Accoding to my calcs for the SM 40:
Dawes Limit = 2.9"
Raleigh Limit at Ha = 4.1"
At FL = 760mm (ED80), each pixel on the DMK 41 = 1.26"
At FL = 1900 (ED80 + 2.5x Powermate), each pixel = 0.5"
Not much wonder the high res shots with the 2.5x Powermate are soft!
Al.