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raymo
07-10-2014, 05:41 PM
I have the SW 8" f/5 Newt which works fine at prime focus, and using EP
projection with the necessary adaptor, but I can't find a way of using just a barlow instead of an eyepiece. A barlow won't quite come to focus when fitted into the EP projection adaptor. Also can anyone tell me if
I can use filters at prime focus. What would I attach the filter to?
raymo

Regulus
07-10-2014, 08:53 PM
Can't help. Don't know enough. However I did recently learn I could take the lens cell off my barlow and screw it into the bottom of the ep.
Might work for ur problem. Not a real solution but it might supply a stop gap.
Trev

raymo
07-10-2014, 10:48 PM
Thanks for the suggestion Trevor, but I want to use the barlow without
an EP. The barlow will focus in my 80mm refractor, but not my Newt.
raymo

doppler
07-10-2014, 11:20 PM
I just slide the 1.25" t mount straight into the barlow and the barlow into the focuser without the eyepiece projection part fitted. Works on my 8"f6 newt.
Rick

raymo
08-10-2014, 01:01 AM
Thanks Rick, sounds like a plan. Now I've just got to try and find a way
to use filters at prime focus.
raymo

glend
08-10-2014, 02:31 AM
What sort of barlow is it Raymo? As indicated some will screw apart, like the GSO 2" ED 2xbarlow which work fine with EPs in my big dob. I am about to try it connected to my DSLR - and have a set of adaptors of various thicknesses to work out the distance.

raymo
08-10-2014, 01:54 PM
Hi Glen, it's a Celestron short 1.25" barlow, and the lens does unscrew. I also have a generic long barlow which does come apart. I don't need to
unscrew anything as Rick's method works fine.
raymo