|
imagine your first filter is Ha.
That means EVERYTHING, except the specific band pass of Ha +/- the sensitivity of the filter gets reflected back out of the scope, and only Ha gets in.
Imagine your second filter is OIII. Not only will that not get any OIII signal because the Ha filter stopped any OIII coming through, but now it blocks Ha and tries to send it back through the scope.
Your SII filter at the back? It's asking what the heck is going on, and why is it so dark.
Net result? Black picture.
As for 2", well that's great, but only if you ever see yourself getting a full frame camera and a scope with a big image circle. If you get neither, then the 2" will provide little benefit.
|