Where do I put the filter?

[beamer3.6m]

Ok, this is my set-up:

DSLR with canon t-ring.

Into this I screw a barlow with the lens removed which acts as a focus extenion tube. This is 1.25" but this is fine.

Question is if I want to use a light pollution filter where would I put it if at all possible - does it screw into the bottom of the barlow where the lens was?

[russ]

If you have a 2" filter you can screw it into the 2"-1.25" adapter. If you have a 1.25" filter it will have to go into the barlow tube.

On my old setup I would have had a nosepiece on the T-adapter and the filter would have been in there.

Russ

[ribuck]

depending on your barlow, if the end of it is threaded you can screw it onto the bottom, or you could just attach the filter to the bottom of your eyepiece before you insert it into the barlow.