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View Full Version here: : 1.25" spacer/washer similar to parfocal rings


DeWynter
06-04-2021, 09:07 AM
I recently put 1.25"-2" adapter to a few my eyepieces to convert them from 1.25" to 2". The biggest problem is that the bottom of the 1.25" eyepiece is exactly as the bottom of the adapter so if I put 2" filter then the bottom of the eyepiece will touch the glass of the filter and scratch it.

Has anyone seen some kind of 1.25" spacer or washer, similar to parfocal rings, but thinner? Like 1 - 1.5mm thick. Just want to put it between eyepiece and the adapter. In the worst case I'll use parfocal rings, but if there is something much thinner I'll rather use it than parfocal rings.

Wilso
06-04-2021, 09:26 AM
Will the 2”filter screw into the bottom of the diagonal instead of the eyepiece?

DeWynter
06-04-2021, 01:35 PM
That's my last resort. :) I prefer to use OIII with 3-4mm exit pupil, UHC Wide-band around 2 - 2.5mm exit pupil and CLS Broad-band around 1 - 1.5mm exit pupil. As the exit pupil gets smaller, the less aggressive filter does better job I'd say. So screwing filters to the diagonal is a bit "complex" even if I have click-lock on the scope.

Wilso
07-04-2021, 01:40 PM
I have used a rubber o ring as a parfocal ring. They work quite well and come in different sizes/thicknesses as well.

DeWynter
07-04-2021, 02:26 PM
Great idea! Thanks, mate!

Don Pensack
09-04-2021, 12:48 AM
Or add a small extension to the adapter, like an empty filter cell or a thin barrel extender like the 14mm Baader Fine Tuning Ring.

DeWynter
09-04-2021, 08:51 AM
Hi Don,
Yes, 14mm Baader Fine Tuning Ring will be even more secure in the diagonal. Thanks!