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Equipment Discussions >> Classic Telescopes

Pages: 1
AaronM
professor emeritus


Reged: 02/02/06

Loc: NRW, Germany
Criterion ASP eyepieces - quality ?? new
      #5688113 - 02/19/13 12:21 AM

Hello friends,

i have the chance to get 3 vintage Criterion eyepieces, that I would like to use with my old ornage C8. They labeled as ASP 30 mm, ASP 18 mm and ASP 12,7 mm in 1,25" barrels. I could get them for 20 !

I don't know anything about Criterion eyepieces, but I guess that they have the Kellner design ?

Whats about the quality ? Should I buy them for my C8, or are they garbage ??

Kind regards, Michael


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Littlegreenman
Post Laureate
*****

Reged: 05/09/05

Loc: Southern California
Re: Criterion ASP eyepieces - quality ?? new [Re: AaronM]
      #5688303 - 02/19/13 04:16 AM

Hi Michael,

Here is a link to a short discussion on this line a few years back:link

A few comments: these are not Kellner's; they are "achromatic symmetrical Plossls." The term Plossl as it has been applied to eyepiece design has not been as standard as you may think. A "symmetrical" Plossl is two groups of doublets that are mirrored in order. Some over the years have marketed or highlighted eyepieces with that design as being a "true (real) Plossl."

So, on the one hand they were trying for the cachet of the "true Plossl" design, while hiding the fact behind the acronym, A.S.P.!

In the link above the general consensus is that they are good or better eyepieces, while also being economical.

I have an 18mm one, branded Bausch & Lomb. It's a nice eyepiece, good contrast, no major problems, and comfortable to look through.

LGM


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Ducky62
professor emeritus


Reged: 10/31/10

Loc: The ATL
Re: Criterion ASP eyepieces - quality ?? new [Re: Littlegreenman]
      #5688705 - 02/19/13 11:28 AM

I have 3 B&L Criterion ASP EPs. If I'm remembering right the 12.7mm was pretty good. If it is 20 for all three (and not each) I can't see how you can go wrong.

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Joe Cepleur
Carpal Tunnel


Reged: 03/18/10

Loc: Dark North Woods
Re: Criterion ASP eyepieces - quality ?? new [Re: AaronM]
      #5688717 - 02/19/13 11:37 AM

With an orange tube C8, the issue is not just how good the view is, given that modern eyepieces will likely be better. There is also the historic value of seeing the view as it would have been seen back when the scope was new. From that point of view, coupled with the consensus that these are good eyepieces anyway--and especially at 20 Euros for the set!--these are must-buys.

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GeneT
Ely Kid
*****

Reged: 11/07/08

Loc: South Texas
Re: Criterion ASP eyepieces - quality ?? new [Re: AaronM]
      #5689217 - 02/19/13 04:26 PM

Mine were just average. They might make a great collector's item. In my opinion, the newer designs are better all around.

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AaronM
professor emeritus


Reged: 02/02/06

Loc: NRW, Germany
Re: Criterion ASP eyepieces - quality ?? new [Re: GeneT]
      #5692052 - 02/21/13 12:30 AM Attachment (21 downloads)

Hello friends,

I did it ! The price was now 22 including shipping ! I suppose, I can't go wrong for this price and my loved old ornge C8 is very eye-piece-friendly !
I will report my first impressions if I have first-light with them ( but here in germany in my town it is raining and cloudy since 4 weeks ).

Regards, your's "Kraut" Michael

Edited by AaronM (02/21/13 12:36 AM)


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BigC
Carpal Tunnel
*****

Reged: 09/29/10

Loc: SE Indiana
Re: Criterion ASP eyepieces - quality ?? [Re: AaronM]
      #5692089 - 02/21/13 01:22 AM

3 A.S.P. for 22 euros is a good deal I think;have he B&L 18 and 30mm here and they seem fine for my scopes.Remember older scopes tended to longer,more forgiving focal lengths.

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Mirzam
Post Laureate
*****

Reged: 04/01/08

Loc: Lovettsville, VA
Re: Criterion ASP eyepieces - quality ?? new [Re: BigC]
      #5692270 - 02/21/13 07:13 AM

The main issue with the ASP's is that the apparent field of view is quite narrow. They are also easy to disasemble and clean, which can mean that elements may get flipped around in the process. I've had several of these eyepieces that had to be restored to place the optical elements back in the proper orientation. If they give nice sharp images on axis then all is well.

By the way, none of mine have had mirror image optical elements so I'm not sure about the name.

JimC


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Karl Fabian
super member
*****

Reged: 11/02/11

Loc: Illinois
Re: Criterion ASP eyepieces - quality ?? new [Re: Mirzam]
      #5693760 - 02/21/13 11:19 PM Attachment (18 downloads)

I have the complete set of ASPs (30, 18, 12,7, 9, 7) Most of my set are Bausch & Lomb labled with one Criterion. They are all identical nice quality manufacture made in Japan Circle Y. They are good eyepieces comparable to typical moderate priced Plossls but as mentioned previously the fields are not large... particularly the 30mm which is about 35 deg. The best of the set is the 18mm with about 48 deg field. The main problem is the filter threads are non-standard. They deliver good performance down to about F6.

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Littlegreenman
Post Laureate
*****

Reged: 05/09/05

Loc: Southern California
Re: Criterion ASP eyepieces - quality ?? new [Re: Mirzam]
      #5693982 - 02/22/13 03:33 AM

Quote:

(snip)

By the way, none of mine have had mirror image optical elements so I'm not sure about the name.

JimC




And I thought I was spreading Truth!

Oh well.
SL


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Jean Mario
member


Reged: 11/21/10

Loc: Québec, Canada, St-Jérôme.
Re: Criterion ASP eyepieces - quality ?? new [Re: Littlegreenman]
      #5779230 - 04/05/13 09:34 AM

I have a lot, branded Bausch & Lomb. It's a nice eyepiece, good contrast, no major problems, and comfortable to look through.

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Steven C
member
****

Reged: 05/25/08

Loc: South East USA
Re: Criterion ASP eyepieces - quality ?? new [Re: Jean Mario]
      #6073279 - 09/10/13 01:52 PM

I have the 12.7mm A.S.P. Spectrum Dispersion eyepiece ... very unique in that you can view the spectra of stars and see the emission and absorption lines. Very cool looking at open clusters ... you can immediately see which "don't belong"

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mattyfatz
Carpal Tunnel
*****

Reged: 12/27/06

Loc: Boise Idaho
Re: Criterion ASP eyepieces - quality ?? new [Re: Steven C]
      #6074157 - 09/10/13 11:34 PM

I'm looking for mine right now. I have 2, 30mm. One is 1/2 inch taller than the other! I never understood why. When I find them I'll post a pic.

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Chuck Hards
Post Laureate
*****

Reged: 05/03/10

Loc: The Great Basin
Re: Criterion ASP eyepieces - quality ?? new [Re: mattyfatz]
      #6074667 - 09/11/13 09:37 AM

I have made many true symmetrical eyepieces over the years, and found them to be exceptional in f-ratios slower than f/8, pretty darn good at f/6 & f/7. Not the widest field in the world, but the definition on-axis is tack-sharp, and not bad a bit further out.
The trick is to not use component achromats that are too fast by themselves. Surplus achromats faster than about f/2 rarely give good definition in a true symmetrical. The field can start curving wickedly.

If a manufacturer actually sold a true symmetrical, chances are that it's decent.

Edited by Chuck Hards (09/11/13 07:59 PM)


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highfnum
Carpal Tunnel
*****

Reged: 09/06/06

Loc: NE USA
Re: Criterion ASP eyepieces - quality ?? new [Re: Chuck Hards]
      #6076436 - 09/12/13 07:23 AM

I have a few
there ok - nothing bad
field of view kinda old fashion


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