H ydrogen alpha filter on DSLR

[wavydavy]

Hi,

        Not to long been back into astronomy, and trying to remember some of my set up. I have a 2" screw thread filter (Red) hydrogen alpha, a modified 350 D canon camera, and was hoping to do some prime focus astrophotography, with the filter and camera combined. If I use my filter and extention tube attached into the camera inside the telescope is this the right kinda set up?? Or is it really only worth it on CCD?? If so do I set the camera to black and white as well??? I currently use a CLS clip on astronomic filter, and have some good results, but after 3 mins or so am noticing the pollution still comes through.........thanks.