Quote:
Originally Posted by Don Pensack
I use two different O-III filters a lot: the Lumicon (12nm bandwidth) and the TeleVue (23nm bandwidth), and for all those reasons.
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Thanks Don! A lot of people dismiss the Tele Vue O-III for being too broad and not a true O-III (according to one independent test that I have seen), yet I think the Tele Vue O-III filter gives a very natural view with lots of stars but also lots of contrast. I use this combination also on 4", 6" & 10" apertures on various objects and particularly like the view of Eta Carina at low power with the Tele Vue O-III. I do also like the Lumicon O-III for its bandwidth and high transmission which gives great results on planetary nebulae as well as the Veil.
I have actually invested in the Tele Vue, Lumicon, Astronomik and Thousand Oaks versions of the O-III over the years and have only just got myself a filter slide but have not yet done any comparisons other that unscrewing on and off eyepieces in the past. Of the filters I have used, the Thousand Oaks gave me the blackest blacks and whitest whites with a 24mm Panoptic at f6.4 with 10.1" aperture, (Suchting mirror).
However I preferred the view the Lumicon gave me as well as the very natural view the Tele Vue gave me and for this reason I invested in 2" versions of these two filters. Eta Carina is even more spectacular with a 41mm Panoptic and either filter on my 10.1" Newtonian. I think the Thousand Oaks is best for larger apertures >12". I will in due course do a better comparison now that I have a filter slide as it will allow for quicker change between filters. I have not tried DGM NPB or O-III and maybe one day curiosity will get the better of me.