Narrow-band filters on a colour camera?

[gorann]

I put this post up on the beginners forum two days ago but had only one response (although a useful one), so I am trying it here.

I am into my first year of AP and now, when my Swedish sky is getting too light, I am thinking about projects for the autumn. One would be to try narrow-band for H alpha, OIII and SII. I have seen amateur results on the web that looks like Hubble pics! However, I only have colour cameras (a Canon EOS 60Da and a Celestron Nightscape), so the question is if these are any good for narrow-band photography. I realize that I will not be using all the pixels (e.g. 1/4 when it comes to H alpha) but these cameras have between 11 and 18 M pixels to start with so could it still be worth while?

Telescopes: Celestron Edge HD8, Explore Scientific 80mm apo, Skywatcher 250p

[RikM]

It should be possible to get something using NB filters over a OSC chip. The problem with having so many pixels is that they are tiny, so not a sensitive as the big fat pixels in lower MP cameras. For NB you need sensitivity and long exposures because the emissions are faint.

[sharkmelley]

It is certainly possible but clearly you won't get the same results as a cooled mono CCD.  For H-alpha you are recording only 1 pixel in 4 and even for these pixels you will find that thermal noise is the main constraint on getting a good signal to noise ratio unless you a using a very fast scope.

Mark

[gorann]

Well, I may soon buy a mono CCD, but I found that there are some people taking very good to incredible pictures with DSLRs and NB filters, here are two:

Brian Allan:

https://plus.google.com/photos/116260312230579398213/albums/5526546312185805697

and Fritz Helmut Hemmerich in the mountains of Teneriffe:

http://dslr-astrophotography.com/dslr-astrophotography-with-fritz-helmut-hemmerich/

https://www.facebook.com/fritzhelmut.hemmerich

Both use modded Sony A7s - I just bought Ha and OIII filters and will give it a try with my modest Canon EOS 60Da