DLSR and CCD h-alpha comparison images

[Lee_P]

Hi all,

I'm sure this must exist somewhere on the forum, but I can't find it... Has anyone made a comparison between images obtained with an unmodded DSLR using an h-alpha filter, and mono cooled CCD with h-alpha filter? I'm sure the CCD will come out on top (lower noise, shorter exposure times etc.) but am curious to see like-for-like comparisons, if any exist.

Thanks to anyone who can help with my curiosity!

[jambouk]

There may be comparisons online. It will greatly depends on the cameras in question, as DSLRs have very different quantum efficiencies from each other, and potentially from cooled CCD cameras. Also the IR cut filter used varies greatly in different DSLR cameras so some may let through next to no Ha whilst others may let through 30% of it. And then there is the Bauer matrix which varies between DSLR cameras, does Ha transmit through just the red, or through the green and blue too? And along with that you have to think about sensor size; usually the DSLR sensor is much bigger than the CCD and that not all targets emit / reflect a large amount of Ha.

I think you may have to just hunt online for compatible images and exposure times.

But it would be interesting to see such direct comparisons.

James