baader ND filter

[madkinggeorge]

Just a quick question. I have a skywatcher 150p and it takes both 1.25 and 2 inch eps and I plan to buy a 0.9 Baader ND filter soon. The thing is all of my eps are 1.25 at the moment but I am planning on buying at least one 2 inch in the near future (17mm hyperion). If I buy a 2 inch filter will I be able to use that on the scopes 2-1.25 adapter allowing me to effectively use it on both size eps or is it a case of having to have both size filters.

Any help much appreciated! Loving learning the moon but it is just so bright!!

Clear skies

[david o]

Yes, as long as the bottom end of the 2">1.25" adapter is threaded to accept filters.

Watch out ! The barrels of some 1.25" EPs are long enough to pass completely through the adapter, so as to come into contact with the surface of any mounted filter.

Moonshane's thread has pictures of the problem and provides a solution : Novel use for Baader Fine Tuning Rings.

HTH