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Was going to nab new RKEs to complete my set and..

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#1 refasali

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Posted 25 January 2013 - 06:45 PM

I realized they've gone up in price since the last time I noticed they went up in price- goodness. $85 a piece now. My limited economic sense tells me that the price of used RKEs will likely follow. Wanted to share.

#2 apfever

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Posted 25 January 2013 - 07:41 PM

Hmm. The original orange rubber ring Edmund RKEs? I didn't even know they were still made. Thought they faded out with the Plossl replacement as standard AstroScan issue.
Yes, performers are going up. Nagler T6s used to be in the 200 to slightly under range, but now go regularly for the 222 area, about 25 up.
It could be that new RKEs are not a hot manufacture item thus more expensive to produce in smaller quantities. It could be the intrinsic vintage value has allowed new prices to increase as well, a retrospect.
My full set has come entirely through various scope purchases.

#3 Glen A W

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Posted 25 January 2013 - 07:55 PM

Probably worth it. You'll keep them the rest of your life... if you have any sense! ;) GW

#4 refasali

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Posted 25 January 2013 - 08:49 PM

I bought a couple eight months ago for $62.5 each- gave some away (along with some astroscans) to interested friends... But I think they ran for $45 in the last twelve months. Used prices seem to float around $30-50.

#5 terraclarke

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Posted 25 January 2013 - 09:34 PM

Is the 28 mm worthy of all the scuttlebutt? It's talked up so much on the net but I've never looked through one. It's said to be the "floating in space eyepiece."

#6 bremms

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Posted 25 January 2013 - 10:26 PM

Had Three of them, all at different times. Really early one that I gave away with a 4.25" scope to a friend. Then got another a few years later. Sold that one when I wasn't doing much amateur astronomy. Got another recently from SS and like the eyepiece. Yes my 32mm and 26mm NJ TV's are better corrected and the Meade RG 28mm is better in most ways. But it DOES have that floating in space thing.. Hard to explain. Works great with my 6" F8 reflector. That being said, I usually use the 32mm TV Plossl. Won't sell 28mm RKE this time. It is special. Love the pinpoint images of the 28mm RGO though. It's even more of a keeper. Those are getting REALLY expensive on the used market.
Anyone notice the asking prices for ZAO's went up $200 in the past few months? They are really good.. but $5-600?

#7 terraclarke

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Posted 25 January 2013 - 10:33 PM

I would like to give one a try but I really need to put a stop to buying eps now that I have completed my Unitron collection. I have so many I have lost count. Has to be over a hundred. Each time I get one I say it's the last. But that one will probably be next :tonofbricks:

Terra

#8 bremms

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Posted 25 January 2013 - 10:35 PM

Terra, Yes, I would say get a used one. It's worth trying. You can always sell the eyepiece if it's not your cup of tea.

#9 terraclarke

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Posted 25 January 2013 - 10:37 PM

But will I need to take a Dramamine tablet before looking through it? :p

Terra

#10 bremms

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Posted 25 January 2013 - 10:41 PM

I'm having the same problem with EP's. I like to buy odd ones.
Zeiss 25mm Huygens,30mm Nagleresque military, some microscope EP's are really good. The Celestron Vixen Kellners are REALLY good in long refractors. Think I need a cease and desist order to stop.

#11 rdandrea

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Posted 25 January 2013 - 10:57 PM

Is the 28 mm worthy of all the scuttlebutt? It's talked up so much on the net but I've never looked through one. It's said to be the "floating in space eyepiece."


If you don't mind the blackouts and kidney-beaning that go with all that eye relief, it's nice. You need to take your time and find the right eye placement then they're very sweet.

I have a 15mm RKE that's one of my favorite eyepieces. The 28, well, not so much.

#12 Astrosetz

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Posted 26 January 2013 - 10:16 AM

Got a used Astroscan off eBay last summer, and it came with a 28mm RKE. Perfect match to that scope. Have since acquired used 15mm and 8mm RKE's -- when it gets warm enough, I'm excited to try them!

#13 Preston Smith

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Posted 26 January 2013 - 10:48 AM

You need to take your time and find the right eye placement then they're very sweet.


I could not have stated it any better! It always takes a second or two to get your eye placement just right with that eyepiece. I enjoy the views with mine.

#14 actionhac

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Posted 26 January 2013 - 12:49 PM

This looks like a gear shift knob from a John Deere tractor but its the grand daddy of the famous Edmund 28mm RKE.
Originally the 28mm was a eyepiece designed for a gun sight, with lots of eye relief to prevent the gun's recoil from poking out an eye.
The anodized black part on this ep is Edmund's adapter so it can be used in a 1.25" focuser. Later versions the entire ep body was made by Edmund to house the surplus lenses.
Go here and scroll to Feb. 3rd 2009 for more RKE:
http://www.petealbre...m/blog/blog.htm
You should go there anyway TONS of neat info.

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#15 refasali

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Posted 26 January 2013 - 05:18 PM

Thanks actionhac! I have one of those surplus eps and have been curious about it. I think mine has a wider fov than my 28mm rke- I definitely prefer the view from it. In reference to the Feb 2009 blog post, I also have one of those gun-metal gray 28mms (no. 5223), but the views don't seem as good as through my old black/red RKEs. Were I to rank them- 1.) Surplus pre-RKE 28mm? 2.) Black/Red 28mm RKE and 3.) lastly those 5223s.

#16 proteus5

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Posted 26 January 2013 - 11:04 PM

Go here and scroll to Feb. 3rd 2009 for more RKE:
http://www.petealbre...m/blog/blog.htm
You should go there anyway TONS of neat info.


Hey, I have one of the pre RKE ones also. It came with a 6" f8 mirror set I got from Edmunds back in the early '80s. I haven't used it in years. Never realized it was anything special :confused:

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#17 bremms

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Posted 27 January 2013 - 12:08 AM

That's the first RKE I had. It was a good deal. Optically good. Not sure it was the RKE design. Pretty sure that one was a Plossl type. The catalog ad says two doublets.

#18 actionhac

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Posted 27 January 2013 - 01:57 AM

This is getting confusing.
I looked back through some Edmund catalogs and in Fall 1977 a "New Edmund Design - The 28mm RKE Eyepiece", but it looks just like the old one!
Redesigned 1976, modified type II Kellner, a reverse Kellner designed by Dr. David Rank.
I guess from 1976 and later the elements are a reversed Kellner design of the old 28mm Kellner, looks the same on the outside but different on the inside apparently.

Pre 1976 are standard Kellner with doublet eye lens and later version will be reversed, doublet field lens.
And I imagine the final red rubber grip RKE's must be the reversed but I also noticed these are advertised as having high index glass.

A little more RKE:
http://www.astronomy...sages/424.shtml

Robert

#19 refasali

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Posted 27 January 2013 - 07:37 AM

Here are my gunmetal no. 5223 and the shifter knob
Posted Image
Listed as (date unknown, cropped from Provin's archive)
Posted Image
and
Posted Image

and Robert, the astronomey.net article you linked mentioned the price going up in 2003 from $39 - $57. Perhaps the ~$45 I saw was on SS, when they had some without the red-band. Either way, $57 - $62.50 - $85 over ten years doesn't seem that bad to me anymore when compared to other things...

#20 actionhac

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Posted 27 January 2013 - 10:51 AM

Hey! you found the Shifter Knob in a catalog!
#50,130 and its 32mm, so its longer than I thought and you are right, probably more field of view than the 28mm. And it has 2 doublets according to the ad. In fact both ads state 2 doublets.
That must be an old catalog to have "war surplus" printed like that. And look at those prices.

Robert

#21 droid

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Posted 27 January 2013 - 11:41 AM

Yeah the new RKEs are now 85.00 a pop. holy cow

#22 rustynailz911

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Posted 27 January 2013 - 11:55 AM

Terra i love my pre RKE K28mm from Carton it is a awesome piece of glass.In my 60mm f7 it gives me a massive 3.3 deg fov and is sharp right to the edge of the field.It was really nice during the conjunction of Jupiter and the Moon last week i could fit it everything in the FOV.I think the ultimate would be to have 2 if em in a binoviewer.

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#23 terraclarke

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Posted 27 January 2013 - 12:14 PM

Okay, now I'm confused. The add above says the ep has two achromats, i.e. two doublets, however both the Kellner and RKE consist of a singlet and a doublet. In the case of the Kellner, the doublet is the eye lens, and with the RKE it's the field lens. With the Kellner, the achromat is Plano-convex, positive side facing the field lens, with the RKE the positive side of the achromat faces the eye lens. The optics of the two eps are essentially reversed. So again, two achromats? What gives? Sounds more like a plossl. :question:

#24 rdandrea

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Posted 27 January 2013 - 12:32 PM

So again, two achromats? What gives? Sounds more like a plossl. :question:


Or a symmetrical/dialsight. I don't recall whether anyone has disassembled one and posted pictures to CN.

#25 bremms

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Posted 27 January 2013 - 12:32 PM

The early "RKE" was Plossl or symmetrical, not a Kellner. It wasn't an RKE. Took mine apart at some time in the mid 80's and it has two achromats. Not positive if it was symmetrical, but pretty sure it was. The RKE was a better eyepiece.






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