Are the Thousand Oaks H-beta and OIII filters considered equivalent in
performance to the Lumicon versions?

I have noticed some slight focusing issues with the Lumicon filters as
it seems stars in the field do not focus to a sharp point when using
the Lumicon UHC.

The Thousand Oaks filters are also about 20% less expensive. I also
like the idea of different colors for the filter rings to aid in
id'ing them in the dark.

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Michael McCulloch