Solved: focus issue with GSO Dob and TV eyepieces

MortonH · #1 14-05-2007, 08:26 PM

Having found that there was not enough out-focus for my Televue eyepieces, then buying the 35mm extender from Bintel and not having enough in-focus, I swapped the extender for the new Bintel 2" to 1.25" adapter with built-in T-thread. It raises the eyepiece a couple of millimetres higher than normal and now the TV eyepieces focus without pulling them out a bit. Perfect!

Morton

Miaplacidus (Brian) · #2 14-05-2007, 10:48 PM

I'm surprised the focuser didn't have at least 35 mm of travel.

MortonH · #3 14-05-2007, 11:05 PM

It seemed like it should work in the shop, but in reality...

Anyway, now I have the perfect solution and a T-threaded adapter to boot!

Morton

MarkN · #4 15-05-2007, 10:07 AM

G'day Morton,

I have had a similar experience with two TV eps. With the 27 Panoptic it turned out that my Bintel 10" was not collimated as well as I thought it was.

Once properly collimated, I could focus the 27 Pano at the very outside; just a couple of mm to spare. That's all one needs though.

The 40 mm Plossl is much too far out of focus to bother.

Mark.

StarLane · #5 16-05-2007, 07:05 PM

Morton, What TV EP`s did you have trouble focusing with??

Do you have the Crayford style focuser that comes standard with the scope? or did you upgrade to something else?

Cheers.