GSO 8x50 Finder scope - focal length??

[Moon]

What focal length are these (http://www.gs-telescope.com/content.asp?id=129) - does 200mm sound about right?


James

[Moon]

PS - has anyone tried this (http://www.teleskop-express.de/shop/product_info.php/language/en/info/p4708_Parfokal-Adapter-auf-T2-fuer-8x50-Sucher-von-TS--GSO--Meade.html) to connect a guide camera?

[bmitchell82]

GSO has a longer tube hence less back focus than my SW finder but 200mm is about right

[gbeal]

Yes, I used one , or one similar to that, until only recently.
Mine plate-solved out to "about" 176mm focal length.
I cobbled together a push fit to T thread, and then a T to C adaptor, fitting the Lodestar to the end. Worked like a charm.
It has been superseded by an OAG and a TS60mm finder-guider.
Neither is significantly better, both cost significantly more.
Gary

[Moon]

Thanks Gary.

I "siliconed" a QHY5 on the back of mine - it works surprisingly well, but I can't use the QHY5 for anything else so a proper adaptor might be in order.
James

[cventer]

from memory I had to cut around 15 mm off back of my GSO 8 x 50 for my starshoot autoguider to work.

I had an old 2" to 1.25 eyepeice adaptor laying about so just used a linisher to sand this down till it press fitted into the back of the finder. Bit of JB weld before press fitting and it aint ever comming out :)

[gbeal]

Yes, like Chris, mine used an old 2" adaptor, which was almost a snug fit in the tube, all I did was add a bit of the "wooly" Velcro section and it was tight.
The new TS finder-guider is a whole new ball game though, very nice.
Gary