Pentax XO's

[TheMightyKong]

Anyone here with experience of these?

Steve, If FLO's coming to Kelling any chance you could bring them along to look through? I've already sent you a PM about this:)

Rishi

[mike bacanin]

The 5mm Pentax XO, which i have used, is probably the best 5mm eyepiece for planetary/lunar observation available.

I actually did not find the very short eye relief a big problem ( about 3mm)

Mike

[KaStern_Former_Member]

The 5mm Pentax XO, which i have used, is probably the best 5mm eyepiece for planetary/lunar observation available.

I second this!

[ollypenrice]

Interesting. One other planetary option might be the revamped monocentrics from TMB. Has anybody tried them? There is something rather romantic about this old high transmission design and I'd love to know more. I gather the eyepiece is getting close to being a contact lens!

Olly.

[TheMightyKong]

Actually I have some supermonos and they are indeed pretty special. Curious to see how the XO's do.

[KaStern_Former_Member]

Hello Ollie,

Interesting. One other planetary option might be the revamped monocentrics from TMB. Has anybody tried them? There is something rather romantic about this old high transmission design and I'd love to know more.

My pal Sven and me were able to compare the 5mm XO to the 5mm TMB Monozentric

(sorry, in german, a translation may help):

Barlow-Test

Eye relief of the mono is better than most would expect it to be. I reckon it might be

about 85% of the focal length. The 5mm XO eyerelief is a little bit shorter.

Using a 4"f/8 TMB Apochromat (russian origin) both were very close on-axis.

Off-axis and for the "wider field" I prefered the XO over the Mono.

Cheers, Karsten

[mike bacanin]

There is a current thread on the 5mm XO on Cloudy Nights.

see in the eyepiece forum.

Mike

[FLO]

The Pentax XO orthoscopic eyepieces are normally special-order items but we will try to have one for Kelling.

HTH

[ollypenrice]

Thanks Karsten.

Olly

[FLO]

Hhhmm... There is something afoot here.

We are seeing increased an interest in the Pentax 5mm XO eyepiece and have received a number of pre-orders. Some are saying that it is discontinued but Pentax-UK aren't aware of that. We did secure their last remaining 5mm "until the next shipment" (they aren't sure when that will be) but it has already sold so we haven't one for Kelling - sorry.

[TheMightyKong]

Ah nevermind, I take it you don't have the 2.5mm XO either?

[FLO]

No, I confess we have never stocked the 2.5mm, the 5mm is the popular one.

[mike bacanin]

The baffling on the 5mm XO is really superb, and in addition to the excellent SMC coatings,contributes to this eyepiece's exceptional performance.

see photo,

Mike

[mike bacanin]

Mighty Kong, PM sent!

Mike