Hydrogen Alpha filters

Hi Guys,

I've been looking at some h-alpha filters (for CCD - not solar) and wondered if any of you imagers out there had any suggestions as to what sort of bandpass is usable from a city with mag 3.5 skies?

The reason I ask is that the Lumicon is cheap and has a bandpass which I believe is about 20nm. OK I know this is very wide but I don't know how narrow you need to go for imaging nebulae. I've seen Astrodon and Custom Scientific going to 3nm but these are incredibly costly.

Another option would be the 2" Baader 7nm. A bit more than I'd like to spend but if the Lumicon is not worth it I would probably go for it.

Many thanks,

Trev

Trevor - I have a very limited knowledge here but I've seen recent posts that aren't very complimentary about Astrodon (in terms of value for money) but rave about Baader. Lumicon are good but my impression is that with the lack of posts mentioning them, few die-hard CCD users have them.

Its a small data point but may help you.

Dave

Thanks for that Dave, this was what I kind of suspected. Oh well, I guess you get what you pay for.

I eventually found some data on the Lumicon site saying that it is not great for imaging using a refractor & CCD. It seems to have been designed for film. It must be terrible if they admit it themselves!

I've always found Baader products to be excellent and good value so I'll think I'll go for that 7nm option.

thanks again,

Trevor