Identifying GS EP's

lost_in_space · #1 26-02-2006, 12:05 AM

I bought 2x 2" EP's with my GS dob, (as well as the 4 "bundled" series 500 plossls). On the box they are marked as GSO SP26mm and GSO SP32mm. The lettering on the EP's themselves only identify them as 26 & 32mm Fully Multi-Coated, but there are no letters indicating what type of EP they are.

Even my old Tasco's had a K, indicating they were Kelners. I was wondering (an idle mind under cloudy skies

) what these 2" are. Does the SP represent anything? Deep diving through google has taught me a lot more than I previously knew about EP's but has provided no enlightenment about these.

Can anyone tell me the type of construction of this EP? Do they have an inbuild barlow (I don't have a 2" barlow yet)?

janoskiss (Steve H) · #2 26-02-2006, 12:24 AM

SP = super plossl = plossl

Starkler (Geoff) · #3 26-02-2006, 01:59 AM

I used to own a 26mm one. They are a 3 element modified Kelner design I beleive and suffer diabolical off axis aberrations in fast scopes.

lost_in_space · #4 26-02-2006, 02:15 AM

Quote:

Originally Posted by Starkler

I used to own a 26mm one. They are a 3 element modified Kelner design I beleive and suffer diabolical off axis aberrations in fast scopes.

Thank you Geoff, that is exactly my perception. I think they may be ok on >7.5, but not right for a fast newt.

I love my new 15mm TV plossl my kids bought me for xmas, don't get much better!