Telescope side opening of the 36mm filter wheel

robertm

Hi,

Could you tell me the size of the telescope side opening for the 36mm filter wheel please. I can see that the camera side is m42 but this seems too restrictive for the telescope side, even though the diagrams say it is m42.

Thanks

Tech@ZWO

robertm It is M42 as well.

andybutt

robertm

Thank you. Does the 5 way 2” filter wheel front plate fit the 7 way 36mm filter wheel and if so then can it be bought separately?

Are there any other solutions?

I’m trying to mate the 36mm filter wheel with my telescope but the telescope side opening is causing vignetting once an adaptor is used. A number of 36mm filter wheels I’ve seen from other manufacturers have either m48 or m54 telescope side opening but won’t work with my ASIAir.

Many thanks
Robert

w7ay

robertm Does the 5 way 2” filter wheel front plate fit the 7 way 36mm filter wheel and if so then can it be bought separately?

No can do. The left is 5x50 EFW with M54 holes, and the right is 7x36 EFW with M42 holes -- different dimensions.

An M42 thread is 42mm, but an adapter's inside diameter will often reduce the clear aperture to even smaller than the filters' clear aperture. ZWO did not include this important warning, leading to needless aperture vignetting by unaware customers.

Chen

robertm

Thank you w7ay. A few poor design decisions there! If only they had only made the two cases the same, or at least the same size, then that could also have lead to simplified production costs. I think I may have to, unfortunately, go with a 7 x 2” with inserts instead or abandon ZWO for this project - what a pain.