2012-04-30 ebay CaK filter

Used with Baader 3.8.

It's slightly better than the Baader CaK which I owned before, and it's cheaper as well.

Someone suggested that since it's bandwidth is very wide, it's virtually white light!  But then the Baader model is even wider, so I did a side by side comparison as below:-

Of course, it's not really very narrow band but it's certainly not white light. Given the strong gusts today, I can only do a testing shot at 2x.