OIII filter effective in 8 inch SCT ?

[John]

I'm getting slightly confused in reading reports on OIII filters and the types of scopes they work well in. Some sources say that 10 inches is the minimum aperture that an OIII filter is worth bothering with while others seem to suggest 6 inches as a minimum. I'm thinking of getting one to use with a Celestron C8 SCT - I already have a Baader UHC-S and the scope comes with an Orion Skyglow (which I found not much use in smaller apertures TBH) - would an OIII be worthwhile as well ?.

Cheers,

John

[Albireo380]

Hi John,

I have a Baader OIII that I use on my 8" Meade LX90. I find that it does allow me to pick out considerably more detail than not using a filter at all. But it depends markedly on seeing conditions and the object in the FOV. M42 gives me much greater nebulosity, for example, but the Trapezium becomes very dim. So, YES - it is probably worth experimenting with on your C8.

Tom