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Old Jul 26, 2002, 8:41 AM   #1
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Default Eyepiece/Adaptors

Maybe this is old news for most of you seasoned digiscopers; but, for anyone with interest, there appears to be some new "scope" eyepiece/adaptors to compete with the Williams Optics DCL-28. As a matter of fact these new eyepiece adaptors have seemed to surpass the performance of the WO DCL-28.

The stated FOV of both of these new wide angle eyepiece adaptors are rated at 66 degrees. That is some very comfortable seeing in anybody's book without even considering how these eyepieces actually perform behind a 9xx series Coolpix.

For starters, there are two sizes: 14mm and 18mm. Hopefully, this lineup will broaden in time with "maybe" a few additions that could include: 10mm, 22, 26, 30, 34, and 40mm sizes.

The 14mm and 18mm would probably fulfill Lin's most recent wish of some additional eyepiece/adaptors with a liitle higher magnification then the WO.

The best part of these eyepiece/adaptors are that they seem not to exhibit any vignetting throughout the zoom range of the Coolpix 9xx series of digital cameras. This lack of vignetting will allow the Coolpix cameras to be used at full wide angle. This is not currently possible with the WO.

And of course, these new eyepiece adaptors come with the standard 28mm lens threads.

Yes, these "chunks of glass" appear to be MINT! I could not resist the claimed performance and have just ordered both sizes for use with my scopes. I hope this family of eyepiece/adaptors continue to broaden with more selections in the future.

Just thought I'd mention the unmentioned because there just hasn't been enough action in this digscoping forum! :P
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Old Aug 7, 2002, 12:26 AM   #2
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I'm very interested, but I think you forgot to mention who makes them or where to find them?
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Old Aug 8, 2002, 6:04 PM   #3
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Yes, a wonderful account of these new items....but as Jim said, with one major flaw.
Obviously they are sooooo good, he's not letting on :-)
Andy B
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Old Aug 10, 2002, 8:42 PM   #4
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Default Sorry.....

Sorry...I figured everybody knew about these eyepieces by now. This appeared evident to me by no interest in subsequent posts up until now. Anyway, check out Scopetronics website. The pieces have changed location a couple times already. The last place I found them on the website was under "Scopetronics Eyepieces." They "ARE NOT" or at least were not listed under "adaptors" last time I checked. There is an informative first look review of these eyepiece/adaptors buried in the text under the decription of the pieces' on that website, so keep the eyeballs peeled!

[Edited on 8-11-2002 by Mr. Billobaggins]
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Old Aug 15, 2002, 11:33 PM   #5
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Thanks for clarification. The only problem I see is that they are only offered in 14mm(36X) and 18mm(28X) for the CP990 28mm threads.

The Magnification numbers are for the Pentax 80ED (FL=504mm)

For me the lower the magnification the better. I would like to get 12X, but the XL-28(18X) or DCL-28(25.2X) from Williams Optic are a better choice, based on this one criteria alone.

The DCL-28 is cheaper but the light falloff is not worth it to me, so I'm back to the XL-28 as my next purchase.

More info is on the Birdpix page in my sig.
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Old Sep 2, 2002, 8:56 AM   #6
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Quote:
The Magnification numbers are for the Pentax 80ED (FL=504mm)
Hi Jim,
Are you certain about this focal length? Pentax quoted me 480mm. The Swarovski 80's are 462mm and the Leica 77's are 440mm. From their comparative tube lengths, 480mm seems more likely, but my information came from a conversation with Pentax and not from published data, so I would like to be sure...

Best regards,

Lin

[Edited on 9-2-2002 by Lin Evans]
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Old Sep 2, 2002, 9:11 AM   #7
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Default Pentax FL

Quote:
Pentax quoted me 480mm
I think someone misquoted to you.

Mag=FL.obj / FL.eye

18X=504mm/28mm
72X=504mm/7mm
etc.

I got the number from filling in the missing factor, FL.obj 18X=FL.obj / 28mm. It works on every eyepiece stat they list and far as I know there are no exceptions to this formula.

You can look at my page on an
Eyepiece comparison I did to see more.
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Old Sep 2, 2002, 10:57 AM   #8
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Hi Jim,
Those figures seem perfectly correct if Pentax is actually giving accurate information for all their eyepieces in terms of precise measurements in focal length.

But, I wonder if they are approximating some of their figures. For example, their 20x-60x zoom eyepiece is quoted as 8.8 ~ 24 mm. Using the lower figure to get 20x would require a focal length on the tube of 480mm (480/24). However, if we used 480 to get 20x on the lower end, it would result in only 54.5x on the top end which would be a good bit off the 60x quoted. On the other hand, if we use 504mm as the tube's focal length, we end up with 21X on the lower end (504/24) and 57.2X on the top end. Neither actually makes a 20X-60X.

It would make more sense that 504mm is correct IF the assumed precise focal length of the eyepieces are reflected by their "X" factors as quoted by Pentax and figured in your calculations - but now I'm wondering if they are truly accurate figures, especially in light of the variable eyepiece discrepancies? It's of relatively little importance at the lower magnifications for viewing, but when you put a 4x CP995 or CP4500 into the mix, the focal lengths on the top end of the zoom change considerably.

I suspect your computed figure of 504mm makes more sense, but it would be nice to get some clarification from Pentax. Maybe an email to their technical support team could get some straight answers.

Best regards,

Lin
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