[Mickoid (Michael)]

I took out the modded Canon 550d with a Pentax 135mm f 3.5 attached last night and shot some data using a 2 inch 7nm Ha filter. I mounted it on an iOptron Sky Tracker pro and I must have nailed the PA pretty close because I managed 3 min subs with it. I actually shot these at 3200 iso in JPG Monochrome format, 15 subs which gave me 45 mins worth. The tracking was so good it unfortunately created walking noise which I was able to slightly reduce by trashing the Blue and Red channels and saving the Green channel as a Grayscale image.

The combined age of the camera and lens I used is over 55 yrs but I reckon this Pentax lens still holds up well and it's one of my favourites for Widefield.