Differences in OIII filters

I have a Thousand Oaks OIII filter and have been very happy with it for over a year......until last week at the Chiefland Star Party where an aquaintance and I compaired my T.O. and his older Lumicon in my 16" f/4.5 dob with filter slide on the Veil Nebula. While the difference was not great, his Lumicon obviously bested my T.O.; we both agreed on that; enough that I'm thinking of replacing my T.O. While talking to a knowledgable vendor later that night he stated that he and others had tested several OIII filters and arrived at this performance order: Televue>old Lumicon>T.O>new Lumicon/Parks. Has anyone else run a similar shootout on OIII filters? What were your results? How about UHC/Ultrablock filters?

Thanks for any insights,
Eddie

I compared a Lumicon (from 2001) with a new Astronomik OIII in my 12.5 f/6 reflector on a couple of occasions. In skies with a LVM of ~5.8, I could detect no difference between them. Only in very transparent skies (LVM ~6.4) did the Lumicon show it had much better contrast on the veil nebula.

I was able to test both filters with a spectrometer and the bandwidth on the Astronomik was wider than the Lumicon and this showed less colouring of stars, was a little brighter and seemed to be more appropriate for smaller aperture scopes.

Here is a website that shows some results from spectral transmission tests with some different deep sky filters.
http://home.freeuk.com/m.gavin/grism2.htm

Gary Weber

I'm afraid I'm lost here: does your scale mean that Televue has the best or the worst of the OIII filters???