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?