eyepiece query (Univ. Optics, KK Wide Scan)

[janoskiss (Steve H)]

Dear fellow Iceinspacers,

I am looking at getting some decent eyepieces and would appreciate any advice from more experienced members.

I am looking for good high magnification views of the planets and for moderate magnification wide views.

After a lot of reading reviews and searching I am leaning toward University Optics (UO) orthoscopics for planets & Moon, a 16mm Kokusai Kohki "Wide Scan" (WS) with 84 degree AFOV as a general purpose EP, and a UO 2.8x Barlow to give me a bit more flexibility. The WS is sold by sirius-optics.com.au for $300, but the UO stuff I'd have to order from the States.

The EPs must perform well in fast scopes. At the moment I have an 8" GSO Dob (f6) and I'm planning to buy a refractor soon (probably an orion/saxon 80mm ED, f7.5).

Any suggestions would be much appreciated.

[ausastronomer (John Bambury)]

Hi Steve,

I don't recommend the Widescans for your purposes, they are not a cheap eyepiece and are not at their best in scopes faster than about F7 or F8. In slow scopes like Mak/Cass etc they are superb. Also I would advise against the UO Klee 2.8 barlow. This barlow can cause vignetting with certain eyepieces. The best 1.25" barlow is the 2.5X TV powermate, no discussion needed. A very good cheaper alternative is the Orion Shorty Plus/Celestron Ultima (same barlow different sticker). This is marginally inferior to the TV Powermate but better than the Klee and will not vignette because of its larger clear aperture (27mm as oposed to about 19mm).

The UO HD orthoscopics are an excellent planetary eyepiece. The only downside with them is short eye-relief in the shorter focal lengths, which if you don't wear glasses isn't a problem and a slightly narrow FOV. Image quality in the HD orthoscopics is superb, as good as any Pentax or Televue eyepiece.

You can buy the HD orthoscopics locally for about $120 to $130.

www.frontieroptics.com

The guy who owns Frontier Optics is a friend of mine and also an Ice in Space member, Daniel Beringer.

If you are watching your $$$$, for your medium power views I think you should consider the 18mm TV radian. You can buy these new for about $380 which compares to about $300 for the widescan. The Radian has a smaller AFOV @ 60 deg but will clearly outperform the widescan in any scope slower than about F8 and it also has 20mm of eye-relief.

If your not worried about price then the 14mm Pentax XW or the 13mm Nagler T6 have a larger TFOV than the 18mm Radian, cost between $400 and $500 and walk all over the widescan in any scope, but perform exceptionally well in fast scopes, as does the Radian.

CS-John B

[asimov (John)]

University Optics Orthoscopics EPs.

http://www.astronomy-electronics-centre.com.au/

You will have to email them for availability & price.

They are S.A. based & all my U.O. Ortho's have come from here.

[janoskiss (Steve H)]

Thanks for the advice so far. I've decided to give wide AFOV EPs a miss. There seems to be nothing affordable out there for a fast scope. I'm just going to get a boring 15 mm TeleVue Plossl from Bintel. Are they the sole TeleVue EP dealer in the country?

I managed to dig up some old S&T Barlow (1997) and EP (1996) reviews through Monash Uni's electronic subscription. The EP report convinced me to go the TV Ploessl. And the Orion Shorty-Plus barlow sounds like the one for me (thanks John; I just can't justify the cost of the TV Powermate. Are you firm on "no discussion needed"?? or can you tell me what more I get from a Powermate that's worth an extra $175? I read the relevant pages at televue.com but it all sounds like a bit of marketing gimmickry to me...)

The ortho's I'm still interested in. I got a quote from Frontier Optics (thanks again John), $125 for the HDs. That sounds pretty good considering the UO website has them listed at $US80. I'm still trying to find a local (Melbourne) dealer though.

[ausastronomer (John Bambury)]

Originally Posted by janoskiss

The Orion Shorty-Plus barlow sounds like the one for me (thanks John; I just can't justify the cost of the TV Powermate. Are you firm on "no discussion needed"?? or can you tell me what more I get from a Powermate that's worth an extra $175?

I own a 2x Orion Shorty plus and a 2.5x TV powermate. I am not scared to use the shorty plus when the 2.5X of the powermate gives me a little too much power for the conditions. Realistically your paying a lot of extra money for a very small gain but price out of the equation the TV powermate is the best barlow available.

The main overall difference is that the TV powermate seems to "get out of the way" and you don't even realise its there, that sensation doesn't happen with any other barlow IMO, with all other barlows you can sense "something is there" even though it may not be intrusive in any way or degrade the image quality.

The gain with the TV powermate depends somewhat on the eyepieces you own and use in conjunction with the barlow. With simple eyepiece designs like TV Plossls or UO HD orthoscopics the Shorty Plus will perform "almost" as well as the powermate and it would take an experienced observer to detect any difference in visible detail. Aside from image quality, a normal barlow extends the eye-relief of the native eyepiece whereas the powermate preserves it, hence with long eye-relief eyepieces like Pentax XW's or TV Radians a normal barlow can tend to push the eye relief out too far making it more difficult to hold the exit pupil. Consequently I find the powermate makes viewing with my Pentax XW's a lot more comfortable than with the shorty plus.

Unless your looking for the ultimate, the Orion Shorty Plus is an excellent product at a very competitive price.

CS-John B

[Starkler (Geoff)]

Originally Posted by ausastronomer

Consequently I find the powermate makes viewing with my Pentax XW's a lot more comfortable than with the shorty plus.

Unless your looking for the ultimate, the Orion Shorty Plus is an excellent product at a very competitive price.

I havent used a powermate, but my Celestron ultima barlow in no way gives me any eye relief difficulties with my Pentax XL's

[cahullian]

My orion shorty plus is the pride and joy of my small but growing collection. You wont regret buying one.

[ausastronomer (John Bambury)]

Originally Posted by Starkler

I havent used a powermate, but my Celestron ultima barlow in no way gives me any eye relief difficulties with my Pentax XL's

Geoff,

It does give eye relief difficulties. It extends the eye-relief from 20mm to about 24mm making it slightly more difficult to hold the exit pupil than when using the powermate. This doesn't cause me any problems, it may do for a less experienced observer. Regardless, it is not as comfortable to observe with the longer eye-relief created by the Shorty Plus compared to the Powermate. There is a good reason Al Nagler designed the Panoptic interface, and this is it. If I didn't have the powermate I would be happy to use the shorty plus all the time, regardless of the eyepieces I own. On the other hand however, the extra $175 I paid for the powermate isn't going to change the course of my life, so I will take the powermate all day every day. As I also said earlier I still use the shorty plus as well as the power mate when the powermate gives me a little too much power. If I could only have 1 ? The powermate in a heartbeat. If $$$$ were an issue? The shorty plus in a heartbeat.

CS-John B