Originally posted by PJ1 Very nice. But I would like to know a bit more. For a start, how does the full spectrum conversion affect the result - in terms of what would I not see with a normal body? I assume the K-01 was attached to a tracking telescope (some kind of refractor, going by the stars). How many images were stacked to get the final result?
The full spectrum conversion makes it more sensitive to hydrogen alpha than a normal one, though Pentax is pretty sensitive to it anyway. Through a normal one there would have been a bit more blue mixed in. I used a Williams Optics Flat 2 reducer and flattener, Optolong CLS filter, and the telescope I used is a TPO 8RC f/8 Ritchey Chretien that has a 1624mm focal length, though the flattener and reducer took it to f/6.4 and 1300mm focal length. The mount is an iOptron ZEQ25, which the current version is the CEM25P that is supposedly way better. Since the moon was so bright and close I did 180 x 30 second exposures at ISO 1600, stacked them in DSS 3.3.6, then did about 5 minutes worth of work in Photoshop CS 5.5.