First Filters

[E_ri_k]

Hey guys, I'm looking into getting some filters for my CCD camera.

What would be a good one to start off with, H-Alpha, O-III or a UHC filter? Light pollution is not a huge issue for me as I have quite dark rural skies.

I mainly want to increase contrast of nebulae, but at $350 each for a 2" filter, I want to get the right ones I guess!

Thanks,
Erik.

[bmitchell82]

what type of CCD do you have?

[E_ri_k]

Brendan, I have a QHY10 Colour CCD.
Erik

[Helo]

Hi Erik;

I have just been going thru this so will be interested to see any other responses but from my limited understanding, with a colour ccd such as you and I have, the LPF or UHC seems to be the best all-round for improving contrast on emission nebulae. A good link showing the spectrum transmitted by several types is at http://www.astrosurf.com/buil/filters/curves.htm and the Astronomik UHC, Lumicon Deep Sky and Baader UHC-S seem to have the best balance for blocking extraneous streetlights, skyglow, etc. while still transmitting the really important bandwidths. I bought the Baader UHC-S because I could not easily locate the Lumicon and Astronomik do not suggest theirs for a low f-ratio (I have a Hyperstar at f2). Not so much use for galaxies I believe or for reflection nebulae. Hope this helps (and is mostly correct ;) ).

[bmitchell82]

The information Peter gave is right.

The issue with OSC cameras and the addition of NB filters is the loss of resolution, you have RGGB and most of the NB data lays in R and B so effectively your loosing 3/4s of your resolution :(

This doesn't mean it wont work, because it does. Just it doesn't work 3/4s as good as a mono CCD.

Stick with your sky glow and contrast increasing filters for now and save your roubles for a mono if you get frisky enough to get deeper into astrophotography

[E_ri_k]

Awesome guys, thanks for the info. That makes sense Brendan about the resolution, I would never have thought of that....I might re-think it then.
Cheers, Erik.