OIII filters - which is the best

[Argonavis]

I purchased an Orion Deep Sky filter in preference to a Lunicon UHC following reading some reviews, and I am very happy with it. I am looking for some similar view on OIII filters.

I can across this site, which provides an interesting comparison between the OIII filters available from various suppliers:

http://www.astroamateur.de/filter/oiii.html

Other than concluding that the Custom Scientific is the "purest"filter (ie you probably wouldn't see any stars at all), they all appear comparable, despite the differences in price.

Anyone have any view on the relative merits of various OIII filters? I suspect that the differences are probably very subtle, and specific to the individual.

any comments?

[elusiver]

be interested in any feedback on this also. Trying to decide between a Broadband LPR or OIII.

el :)

[Starkler]

They are very different filters for very different jobs. The UHC filter sits in the middle between those two extremes.

[iceman]

I've recently purchased the DGM Optics NPR filter (narrowband). I haven't done any conclusive tests yet, but we gave it a brief comparison (on only 2 objects, it was brief!) last time up at Kulnura against an Astronomik OIII and a Celestron one (Louie's).

They all performed slightly differently, some showed more stars, some showed more nebula, some showed better contrast.

I'll be doing a more comprehensive review next time up at Kulnura to give you a more definite answer, but it certainly performs well for AU$80, compared to AU$190 for the astronomik.

[dhumpie]

See if you can find that review by Phil Harrington in the Astronomy magazine about 2-3 months ago. He did quite a comprehensive review of the latest filters out there.

Darren

[ausastronomer]

Mike,

That wasn't the Astronomik OIII it was the Astronomik UHC.

CS-John B

[ausastronomer]

Argo,

The Astronomic OIII is a very good filter and will work particularly well in your scope due to its high light grasp. It is also 1 of the most expensive. The Lumicon OIII is also very good and I haven't used any of the others.

CS-John B

[square_peg114GT]

Spectral analysis on this website (http://home.freeuk.com/m.gavin/grism2.htm) shows that the Lumicon is focused more narrowly on the 2 desired O-III lines than the Astronomik or Televue O-III filters. The new Orion O-III filter is purported (http://www.cloudynights.com/ubbthreads/showthreaded.php/Cat/0/Number/594617/page/0/view/collapsed/sb/5/o/all/vc/1) to be weak at the 501nm line.

[mickoking]

I own a Lumicon OIII and the views are fantastic in particular the Eta Carinae neb and Helix planetary. But I have never tried any of the other OIII filters. I also have a lumicon deep sky filter which compliments the OIII nicely.

[xrekcor]

Yeah! but look at the bleeding at either end of the spectrum. I'm no optical
technican but the Astronomiks OIII looks to be the clear winner there

regards,CS

[square_peg114GT]

That's a good point, Rob. I was too busy focusing on the center of those test results to notice that. I wonder how sensitive our eyes are at those wavelengths.

[xrekcor]

Not sure I aren't an expert, but considering his test sources "pointed at a white card or sky illuminated by sunlight" and "four emission lamps with daylight spectrum [reflected sunlight] for comparison" also noting all the primaries are there. I would think this is in the visual spectrum. Anyhow why filter out what you cant see anyways, probably why folks dont use an IR filter for visual observations, because we can see in IR

Perhaps someone else has a better answer.

regards,CS

[Zubenel]

If Astronmics O3 is as good as their UHC filter then thats what I would buy . I did an exhaustive visual test of the Grus PN last year at QLD Astrofest against the Astronomics & Lumicon UHC and the image was noticeably brighterin the Astronomics. I also would like to purchase the "best "O3 filter on the market. Cheers Zubenel.