Light pollution filter

[pyrasanth]

I have a couple of questions to bounce of  you esteemed  experts but first thing to say is a Happy New Year to all of you.

I am plagued with the hideous specter of light pollution so my subs are limited at least in LRGB to about 8 minutes before the light pollution becomes an issue. I am going to invest in a 2" version of the best light pollution filter available. My concern is how to screw the filter into the Atik EFW2 filter wheel so I can continue attaching the camera remembering that the filter is taking up the thread that would normally allow the CCD camera to attach. I'm trying not to use a nose-piece to carry the filter inside as this could introduce errors with the plane of the CCD not being parallel with the optical plane if not carefully fitted. is there such an adapter which will screw into the Atik which would allow the filter to attach then duplicate the T-thread for the CCD camera. Let me know if you know of a solution as I said I'm trying to avoid a nose-piece fitting as threads are better. If you can think of any other solutions then please post remembering that the IDAS filter needs to be in front of the filter wheel. It cant go directly into the optical plane as I plan to use an ONAG guider which throws the light through its mirror to the filter holder. I suspect that this filter would block the near infra-red making the ONAG inoperable so its placement must come after the light beam is split by the ONAG mirror.

The second question is the IDAS filter itself. Can it stay in place for narrow-band imaging.  My filter wheel is loaded with both narrow-band & LRGB filters hence it would be very inconvenient to have to remove the IDAS filter on every occasion when narrow-band was required. This most probably would affect the flats hence it would be a royal pain.

Thanks for any help or advice you can give.

Clear skies to you all.

[pyrasanth]

I found the solution to both issues. This looks like a really useful piece of kit & does exactly what I want:

https://www.secure-eshop.com/epages/www_astrograph_net.sf/secbe88710616/?ObjectPath=/Shops/www_astrograph_net/Products/AGTSOFILHOL