Advice on Astrodon 3nm/5nm Narrow-band Filters

Thanks Dave,

I'll have to see what this tescos does when it opens in March. With it been a couple of miles away people are saying it's going to be the biggest one in Ireland. Why do they have to put glass roofs on this things :>(

How would the standard Astronomik filters compare (obviously not as high a spec).?
I'm in a similar situation Carl. I live just behind the St Kilda training grounds and the skyglow from Melbourne is really bad. I can't do any normal imaging from the backyard so it means a one hour trip out to the club observing site everytime to do any kind of imaging. The site is OK but even there it is completely washed out to the south due to Melbourne's skyglow.I was considering getting a H alpha and modding the 450d camera.
Good luck with the purchase. As you said there is only one opportunity to get it right with those sums of money involved.
FYI. there is a full set of Astrodon filters for sale on ice in space at the moment by Martin Pugh who I think is in the UK.

www.iceinspace.com.au/forum/showthread.php?t=69915

Carl,

I have been using narrow band filters for about 5 years. I have used the O III, S II and H Alpha. My site is dark
located which has a rating of 2 on the Bortle scale and has a limiting magnitude of 7.1-7.5. I have had clear night with readings on average of 21.55 +/-0.5 (Sky Brightness mag/arcsec). These measurements are taken at zenith with a Moonless sky with a SQM. This meant that you could apply a 3nm band with long exposures. However, because of the good dark skies it made sense to use wide 12nm filters. (Astronomik filters)

Because of your location, I suspect your Bortle class 4 with 21.3 to 20.8 (Sky Brightness mag/arcsec. In your case I would go for 6 nm wide or below. The limiting factor will be exposure time. The exposures of course will be much longer. However, with short exposures you may get away with 10nm width.

Eamonn A

www.kingslandobservatory.com