Wednesday 3 April 2013

CaK Closeup - 2nd April

CaK closeup colour by Mark Townley
CaK closeup colour, a photo by Mark Townley on Flickr.

There is lots to see in this closeup of the active northeast quadrant of the sun taken with the 100mm frac at 1600mm focal length. My homebrew CaK filter seems to really like working at these longer focal ratios - maybe time to start consider operating it in a collimated beam?