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Lumicon O-III or UHC Filter

Started by JetsfrLife27, 06/18/2003 09:06PM
Posted 06/18/2003 09:06PM Opening Post
Hello, I'm looking to buy my first nebula filter. I have an Orion Dobsonian XT 10 reflector. The problem is, I have a 27 panoptic (2 inch barrel) and Type 6 Naglers (1-1/4 inch barrel) and don't know which filter to get. I was thinking of immediately getting a 1-1/4 lumicon UHC filter and then saving up for a 2 inch O-III filter. Do you think this is a good idea? What is the maximum power that you can use O-III filters for? The 27 panoptic gives me 46x while the other 1-1/4" eyepieces give me 96x, 142x, 189x, and 250x. I was planning on using the UHC primarily on planetary nebula (M27, M57, Owl nebula) but I read that the O-III is better for planetaries and the UHC was better on emission nebuala. I also read that some objects (Veil, Orion, Lagoon, etc...) look great under the O-III filter. Please give me some advice/information so I can make a wise purchase.

Thanks, Bryan
Posted 06/18/2003 09:15PM #1
I'd say go with the 2" filter and screw it into the front of the diagonal, that way it'll work for all eyepieces.

There's really no separate maximum power for using a well-made filter, other than running out of light.
The UHC is more versatile, the OIII better for some objects. See this discussion: http://www.cloudynights.com/howto/filters.htm

Finally, also consider this filter: http://www.astrovid.com/Astronomik%20Filters_files/Astronomik%20Filters.htm (I'd rather link you to Anacortes, but Herb apparently doesn't sell these?). Prices are comparable to the Lumicon, but the filter material/coating is reportedly more durable and the glass is polished better as well.
Posted 06/19/2003 05:27AM #2
The OIII is better on both emission and planetary nebulas. It's only problem is that it extinguishes stars too much for some people's liking.

I loved and used my O111 for years, until I also got an Ultrablock. It showed somewhat less than the O111, but the views were often far more pleasing. I now keep the O111 mainly for the tough planetaries.
Renato