Comments on Pretoria eyepiece???

[Merlin66 (Ken)]

As you may have seen in the buy/ sell and on AM, I'm trying to find a Pretoria eyepiece. So far no success, but I was hoping someone might have had one who could comment on the " coma" correction for fast systems.
When these were designed by Klee back in the 80's they caused quite a stir but for some reason UO did not maintain production. BTW the Klee barlow, developed at the same type is still available through Helix in the US.

Anyone got any info!!!

[Starkler (Geoff)]

I have only seen a few mentions of them with no real information or useful evaluations. When I saw your wanted ad I thought, "now thats wishful thinking"
Being such a rare item I imagine they are something of a collectors item, as the Meade s4000 14mm UWA is now becomming. Nobody wants to sell them !

[ausastronomer (John Bambury)]

Hi,

Pretoria Eyepiece:

I recall them being talked about in the late 80's but I have never seen one. I don't know anyone that has ever used 1 even. It does get a very brief mention in Telescope Optics by Rutten and Van Venrooij, but they don't go on to say whether it works or not. Paraccor sounds a lot easier to me

UO 2.8X KLee Barlow:

I have used these a few times. They are light and very sharp on axis with good light transmission. It has a small clear aperture of only about 19mm and can vignette with some widefield eyepieces particularly with focal lengths over about 20mm. Eyepieces like the 19mm Pan, 22mm Pan and 24mm Pan all struggle with it. If you only plan to barlow shorter focal length simple design eyepieces, like plossls and orthos it's a really good barlow.

CS-John B