On Aug 2, 2020, at 7:30 PM, Stuart <stuart.j.heggie@...> wrote:



Robert, not seeing any "informed" replies so I'll chime in with what little I know. The issue about UV filters for refractors vs. compound scopes would not apply to an AP refractor. My FSQn had terrible blue halos around bright (blue'ish) stars. The New-Q's apparently fixed that. This would NOT be an issue for an AP scope tho.

My vote is you do not need a UV filter.

Stuart Heggie

http://www.stuartheggie.com/

On Sun, 2 Aug 2020 at 19:39, Robert Chozick via groups.io <rchozick=aol.com@groups.io> wrote:

They say the sensor on the ZWO ASI2600 has an IR Cut filter.  I took it to mean it is just IR and not UV also so I use the IR-UV filter.  I would like to know if anyone knows if an IR Cut filter is all you need with a refractor or if you also need the UV part.  My understanding is that you only need these filters with a refractor but if you use a catadioptric scope with a field flattener or tele-compressor that the glass elements of those additions also require it.  I would love to not use the extra filter.  My FSQ definitely needs a filter for bright stars.

Does anyone know the story here?

Robert

On Aug 2, 2020, at 6:24 PM, Andrew Arai <andrewarai@...> wrote:

Robert,

I have been thinking about getting a ZWO ASI2600.
Do you actually need a UV.IR filter to add potential reflections? I thought the glass cover for the camera provides UV/IR protection.

Andrew

Robert Chozick

rchozick@...

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Stuart
http://www.astrofoto.ca/stuartheggie/