Re: New O-III Filter???

Steve,

How big is your scope? I have a 5 inch Mak and I get limited value from an O-III filter because I pull in so little light to begin with that the filter really cuts into my already limited light supply. I does turn things green and it has sort mirror like finish.

It works well for me on bright objects but looking at things that are pushing the limits of my litte scope it reduces light to the point that I just don't get enough light despite the increased contrast.

My guess is that O-III filters probably work more efficiently on 8 inch or large scopes where you have some light gathering capacity to spare, but maybe you are already there.

Daryl

My Astronomik OIII filter gives me green stars...My older Lumicon OIII filter gave me pinkish/red stars, as well as a hint of astigmatism. The Orion Ultrablock I had gave me blue stars, so I guess that all of these narrowband/line filters add some sort of color to stars. But, when used on the intended targets, like planetary nebulae or emission nebulae, I get no added color to speak of (other than on field stars, of course), and the detail is greatly enhanced.

FWIW, I have used at least one of the above filters in an MN66, 8" dob, 14.5" Starmaster and 18" Starmaster.

Doug
Midway, FL

Steve,

You're out my league. I have a Orion 5 inch Mak and an Orion filter. My little light bucket can't afford the loss of any photons. Things like M1 are a little better, M57 is toss-up. M42 is good with the filter. I lose so much light that I have to find the object and then put the filter on or I can't see my reference stars to find anything. A bigger scope is definitely in my near future plans.

Daryl