Edmund RKE a classic or outdated?

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Edmund RKE a classic or outdated?

#1

Post by helicon »


I still have my circa 1979 Edmund Scientific RKE, a modified Kellner design which Edmund patented back in the 1970's. It came with my red tube 4.25" reflector known as the Super Space Conqueror. Since the scope was f/10 it was pretty forgiving on eyepieces and even Kellners worked fine. Anyone still have an original RKE?



I still use mine in my 6" achromat. I think there was a hiatus as Edmund's business waned but it was reborn as Edmund Optics and they are still selling the design. Just curious what others think of them? Not as well-known as the Astroscan was in the 1970's but still an important piece of eyepiece lore.
-Michael
Dobsonian: 10" Zhumell f/4.9
Refractors: ES AR152 f/6.5 Achromat on Twilight II, Celestron 102mm XLT f/9.8, KOWA 90mm spotting scope
Grab-n-go: AWB 5.1" Onesky Newtonian
Binoculars: Oberwerk 25x100, Celestron SkyMaster 15x70, Bushnell 10x50
Eyepieces: Explore Scientific line, GSO Superview, 9mm Plossl, Edmund 28mm RKE, Celestron 25mm Plossl
Camera: ZWO ASI 120
Naked Eye: Two Eyeballs
Latitude: 48.7229° N
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Re: Edmund RKE a classic or outdated?

#2

Post by notFritzArgelander »


I don't have one. This is only because, having what I have, it's easy to ignore temptation to buy the set. I'd vote for classic. I've had a quick look through them on other's kit. When I'm in a good mood, the floating field effect gets me giggly. When I'm grumpy, it's too gimmicky. :)
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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Re: Edmund RKE a classic or outdated?

#3

Post by Lady Fraktor »


I do like the RKE eyepieces, so classics for me and still use them.
Besides the 28mm with its party trick the line is actually quite good and the prices still reasonable.
Ordering them in EU can get expensive with duty and taxes though. (€ 102+20% DPH here)
The 15mm and 21,5mm are standouts but I do not think they are produced anymore.
For refractors the RKE barlow is much to long but is good for large (300mm+) newtonians
See Far Sticks: Antares 105mm f/15 (modified), AOM 105mm f/9.5, Celestron 150mm f/8 (modified), Stellarvue NHNG DX 80mm f/6.9, TAL 100RS f/10, Vixen SD115s f/7.7
HD Pointy Things: EQ-5, TAL MT-1, Vixen SXP, Vixen AXJ
LD Pointy Things: Celestron SLT, Manfrotto 055B/ RC128, Manfrotto 028B/ Stellarvue M2C/ Argo Navis
Light Benders: 2” Astro-Physics MaxBright, 2” Stellarvue Deluxe, 2” TAL/ NPZ dielectric, 2” Baader Amici prism, 2” Long Perng Amici prism, 2” Baader Herschel wedge, Vixen 1.25" flip mirror
Jewellery: Antares to Zeiss, now only slightly more than 1 person requires!
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Re: Edmund RKE a classic or outdated?

#4

Post by helicon »


I still have the cheap 3x barlow that came with the Edmund scope, but it's relegated to the junk drawer. I don't list it in my signature. Hard for me to throw anything astronomical away.
-Michael
Dobsonian: 10" Zhumell f/4.9
Refractors: ES AR152 f/6.5 Achromat on Twilight II, Celestron 102mm XLT f/9.8, KOWA 90mm spotting scope
Grab-n-go: AWB 5.1" Onesky Newtonian
Binoculars: Oberwerk 25x100, Celestron SkyMaster 15x70, Bushnell 10x50
Eyepieces: Explore Scientific line, GSO Superview, 9mm Plossl, Edmund 28mm RKE, Celestron 25mm Plossl
Camera: ZWO ASI 120
Naked Eye: Two Eyeballs
Latitude: 48.7229° N
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Re: Edmund RKE a classic or outdated?

#5

Post by Lady Fraktor »


I have a hard time getting rid of astro things as well until it becomes a issue :lol:
If I listed everything I would not have room to comment!

Is it a different barlow from the RKE 2.5x?
It is not my best barlow but it does work reasonably well.
These long barlows were designed for use with newtonian telescopes to have the light cone entering closer to the secondary.
It works well in my f/10 - f/15 refractors but I would not use it in anything shorter.
See Far Sticks: Antares 105mm f/15 (modified), AOM 105mm f/9.5, Celestron 150mm f/8 (modified), Stellarvue NHNG DX 80mm f/6.9, TAL 100RS f/10, Vixen SD115s f/7.7
HD Pointy Things: EQ-5, TAL MT-1, Vixen SXP, Vixen AXJ
LD Pointy Things: Celestron SLT, Manfrotto 055B/ RC128, Manfrotto 028B/ Stellarvue M2C/ Argo Navis
Light Benders: 2” Astro-Physics MaxBright, 2” Stellarvue Deluxe, 2” TAL/ NPZ dielectric, 2” Baader Amici prism, 2” Long Perng Amici prism, 2” Baader Herschel wedge, Vixen 1.25" flip mirror
Jewellery: Antares to Zeiss, now only slightly more than 1 person requires!
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Re: Edmund RKE a classic or outdated?

#6

Post by helicon »


I meant the 2.5x in general I am not a barlow fan but it worked pretty well with the 4.25" I remember zeroing in on the Trapezium through it, Hey there are four stars!
-Michael
Dobsonian: 10" Zhumell f/4.9
Refractors: ES AR152 f/6.5 Achromat on Twilight II, Celestron 102mm XLT f/9.8, KOWA 90mm spotting scope
Grab-n-go: AWB 5.1" Onesky Newtonian
Binoculars: Oberwerk 25x100, Celestron SkyMaster 15x70, Bushnell 10x50
Eyepieces: Explore Scientific line, GSO Superview, 9mm Plossl, Edmund 28mm RKE, Celestron 25mm Plossl
Camera: ZWO ASI 120
Naked Eye: Two Eyeballs
Latitude: 48.7229° N
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Re: Edmund RKE a classic or outdated?

#7

Post by Lady Fraktor »


Since you have the 28mm, you should look for a 15mm.
They are usually not very expensive used and was one of the best from the lineup.

Barlows for me are view dependant. When I do use them I actually like using odd incremental barlows.
1.6x, 1.8x, 2.4x etcetera. I have had a 2x TeleVue powermate for better than a decade now and I think I have used it maybe 3-4 times...
It does make a good but expensive paperweight though :)
See Far Sticks: Antares 105mm f/15 (modified), AOM 105mm f/9.5, Celestron 150mm f/8 (modified), Stellarvue NHNG DX 80mm f/6.9, TAL 100RS f/10, Vixen SD115s f/7.7
HD Pointy Things: EQ-5, TAL MT-1, Vixen SXP, Vixen AXJ
LD Pointy Things: Celestron SLT, Manfrotto 055B/ RC128, Manfrotto 028B/ Stellarvue M2C/ Argo Navis
Light Benders: 2” Astro-Physics MaxBright, 2” Stellarvue Deluxe, 2” TAL/ NPZ dielectric, 2” Baader Amici prism, 2” Long Perng Amici prism, 2” Baader Herschel wedge, Vixen 1.25" flip mirror
Jewellery: Antares to Zeiss, now only slightly more than 1 person requires!
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Re: Edmund RKE a classic or outdated?

#8

Post by helicon »


I should get a 15mm as well!
-Michael
Dobsonian: 10" Zhumell f/4.9
Refractors: ES AR152 f/6.5 Achromat on Twilight II, Celestron 102mm XLT f/9.8, KOWA 90mm spotting scope
Grab-n-go: AWB 5.1" Onesky Newtonian
Binoculars: Oberwerk 25x100, Celestron SkyMaster 15x70, Bushnell 10x50
Eyepieces: Explore Scientific line, GSO Superview, 9mm Plossl, Edmund 28mm RKE, Celestron 25mm Plossl
Camera: ZWO ASI 120
Naked Eye: Two Eyeballs
Latitude: 48.7229° N
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Re: Edmund RKE a classic or outdated?

#9

Post by Lady Fraktor »


Hopefully sometime this month I may be able to recommend a 20mm as well :)

I really need to pay attention when tired, the incoming 20mm is a Brandon not a RKE.
See Far Sticks: Antares 105mm f/15 (modified), AOM 105mm f/9.5, Celestron 150mm f/8 (modified), Stellarvue NHNG DX 80mm f/6.9, TAL 100RS f/10, Vixen SD115s f/7.7
HD Pointy Things: EQ-5, TAL MT-1, Vixen SXP, Vixen AXJ
LD Pointy Things: Celestron SLT, Manfrotto 055B/ RC128, Manfrotto 028B/ Stellarvue M2C/ Argo Navis
Light Benders: 2” Astro-Physics MaxBright, 2” Stellarvue Deluxe, 2” TAL/ NPZ dielectric, 2” Baader Amici prism, 2” Long Perng Amici prism, 2” Baader Herschel wedge, Vixen 1.25" flip mirror
Jewellery: Antares to Zeiss, now only slightly more than 1 person requires!
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Re: Edmund RKE a classic or outdated?

#10

Post by WilliamPaolini »


I cannibalized from other EPs so could have a nice weighty chromed brass barrel on my set. They perform great in my scopes and show star colors exceptionally well - always want to keep a single coat set around. No one has a same barrel type as used for the 28.7mm so I just buffed the anodized layer off. RKE = Rank, Kaspereit, Erfle per the Edmund patent submission FYI. The pre-RKE 28.7mm, usually marked as a 1-1/8", is an asymmetrical Plossl war surplus optic.
RKEs Only (web).jpg
-Bill

U.S.A.F. Veteran - Visual Amateur Astronomer since 1966 - Fully Retired since 2019
8" f/5 Newt - Lunt 152 f/7.9 - TSA 102 f/8 - Vixen 81S f/7.7 - P.S.T. - Pentax 65ED II - Nikon 12x50 AE
Pentax XWs - Baader Morpheus - Takahashi LEs - Edmund RKEs - BST Starguiders - 6ZAO-II/5XO/4Abbe
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Re: Edmund RKE a classic or outdated?

#11

Post by Lady Fraktor »


I love my RKE and have used then for quite a few years.
See Far Sticks: Antares 105mm f/15 (modified), AOM 105mm f/9.5, Celestron 150mm f/8 (modified), Stellarvue NHNG DX 80mm f/6.9, TAL 100RS f/10, Vixen SD115s f/7.7
HD Pointy Things: EQ-5, TAL MT-1, Vixen SXP, Vixen AXJ
LD Pointy Things: Celestron SLT, Manfrotto 055B/ RC128, Manfrotto 028B/ Stellarvue M2C/ Argo Navis
Light Benders: 2” Astro-Physics MaxBright, 2” Stellarvue Deluxe, 2” TAL/ NPZ dielectric, 2” Baader Amici prism, 2” Long Perng Amici prism, 2” Baader Herschel wedge, Vixen 1.25" flip mirror
Jewellery: Antares to Zeiss, now only slightly more than 1 person requires!
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Re: Edmund RKE a classic or outdated?

#12

Post by WilliamPaolini »


Lady Fraktor wrote: Tue Jan 10, 2023 5:27 am I love my RKE and have used then for quite a few years.
I have bought and sold more than 300 different eyepieces over the years so have been through a lot. I had a full set of the RKEs that I added the chromed brass barrels to and after a few years sold them. Of all the eyepieces I have been through and let go of, that set was the only one I truly regretted selling. So some years later I reacquired the RKEs once more, and was lucky to be able to source a 15mm used as that focal length was already discontinued by Edmund. I have to say that will NEVER let go of my current set! I feel the same way about the Takahashi LEs. Both lines just have what I consider a unique gestalt about them that makes them special and enjoyable.
-Bill

U.S.A.F. Veteran - Visual Amateur Astronomer since 1966 - Fully Retired since 2019
8" f/5 Newt - Lunt 152 f/7.9 - TSA 102 f/8 - Vixen 81S f/7.7 - P.S.T. - Pentax 65ED II - Nikon 12x50 AE
Pentax XWs - Baader Morpheus - Takahashi LEs - Edmund RKEs - BST Starguiders - 6ZAO-II/5XO/4Abbe
PM and Email communications always welcomed
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Re: Edmund RKE a classic or outdated?

#13

Post by Lady Fraktor »


I have done a mass purge of eyepieces over the last year but the RKE remain. I only have a few Tak LE but enjoy the ones I do have.
See Far Sticks: Antares 105mm f/15 (modified), AOM 105mm f/9.5, Celestron 150mm f/8 (modified), Stellarvue NHNG DX 80mm f/6.9, TAL 100RS f/10, Vixen SD115s f/7.7
HD Pointy Things: EQ-5, TAL MT-1, Vixen SXP, Vixen AXJ
LD Pointy Things: Celestron SLT, Manfrotto 055B/ RC128, Manfrotto 028B/ Stellarvue M2C/ Argo Navis
Light Benders: 2” Astro-Physics MaxBright, 2” Stellarvue Deluxe, 2” TAL/ NPZ dielectric, 2” Baader Amici prism, 2” Long Perng Amici prism, 2” Baader Herschel wedge, Vixen 1.25" flip mirror
Jewellery: Antares to Zeiss, now only slightly more than 1 person requires!
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Re: Edmund RKE a classic or outdated?

#14

Post by helicon »


WilliamPaolini wrote: Tue Jan 10, 2023 6:20 pm
Lady Fraktor wrote: Tue Jan 10, 2023 5:27 am I love my RKE and have used then for quite a few years.
I have bought and sold more than 300 different eyepieces over the years so have been through a lot. I had a full set of the RKEs that I added the chromed brass barrels to and after a few years sold them. Of all the eyepieces I have been through and let go of, that set was the only one I truly regretted selling. So some years later I reacquired the RKEs once more, and was lucky to be able to source a 15mm used as that focal length was already discontinued by Edmund. I have to say that will NEVER let go of my current set! I feel the same way about the Takahashi LEs. Both lines just have what I consider a unique gestalt about them that makes them special and enjoyable.
Good to hear. The 28mm always has been a nice performer.
-Michael
Dobsonian: 10" Zhumell f/4.9
Refractors: ES AR152 f/6.5 Achromat on Twilight II, Celestron 102mm XLT f/9.8, KOWA 90mm spotting scope
Grab-n-go: AWB 5.1" Onesky Newtonian
Binoculars: Oberwerk 25x100, Celestron SkyMaster 15x70, Bushnell 10x50
Eyepieces: Explore Scientific line, GSO Superview, 9mm Plossl, Edmund 28mm RKE, Celestron 25mm Plossl
Camera: ZWO ASI 120
Naked Eye: Two Eyeballs
Latitude: 48.7229° N
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Re: Edmund RKE a classic or outdated?

#15

Post by John Baars »


helicon wrote: Mon Jan 16, 2023 11:28 pm The 28mm always has been a nice performer.
So it is. I have mine some twelve years. Especially for the nice floating field effect. I use it mainly in my f/13 Mak. I used to have a 15mm too, but eventually sold it again as my 14mm Baader Morpheus outclassed it by far.
Telescopes in frequency of use : *SW Evostar 120ED F/7.5, * Vixen 102ED F/9 on Vixen GPDX. GrabnGo on Alt / AZ : *OMC140 Mak F/14.3, *SW 102 Mak F/13, *SW Startravel 102 F/5
Most used Eyepieces: *Panoptic 24, *Morpheus 14, *Leica ASPH zoom, *Zeiss barlow, *Pentax XO5.
Commonly used bino's: *Jena 10X50 , * Canon 10X30 IS, *Swarovski Habicht 7X42, * Celestron 15X70, *Kasai 2.3X40
Rijswijk Public Observatory: * Astro-Physics Starfire 130 f/8, * 6 inch Newton, * C8, * Meade 14 inch SCT on EQ8, *Lunt.
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Re: Edmund RKE a classic or outdated?

#16

Post by helicon »


John Baars wrote: Thu Jan 26, 2023 9:13 am
helicon wrote: Mon Jan 16, 2023 11:28 pm The 28mm always has been a nice performer.
So it is. I have mine some twelve years. Especially for the nice floating field effect. I use it mainly in my f/13 Mak. I used to have a 15mm too, but eventually sold it again as my 14mm Baader Morpheus outclassed it by far.
They seem to have quite a lifespan!
-Michael
Dobsonian: 10" Zhumell f/4.9
Refractors: ES AR152 f/6.5 Achromat on Twilight II, Celestron 102mm XLT f/9.8, KOWA 90mm spotting scope
Grab-n-go: AWB 5.1" Onesky Newtonian
Binoculars: Oberwerk 25x100, Celestron SkyMaster 15x70, Bushnell 10x50
Eyepieces: Explore Scientific line, GSO Superview, 9mm Plossl, Edmund 28mm RKE, Celestron 25mm Plossl
Camera: ZWO ASI 120
Naked Eye: Two Eyeballs
Latitude: 48.7229° N
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Re: Edmund RKE a classic or outdated?

#17

Post by Lady Fraktor »


helicon wrote: Thu Jan 26, 2023 3:14 pm They seem to have quite a lifespan!
I think I have had my set for about 12-15 years as well.
See Far Sticks: Antares 105mm f/15 (modified), AOM 105mm f/9.5, Celestron 150mm f/8 (modified), Stellarvue NHNG DX 80mm f/6.9, TAL 100RS f/10, Vixen SD115s f/7.7
HD Pointy Things: EQ-5, TAL MT-1, Vixen SXP, Vixen AXJ
LD Pointy Things: Celestron SLT, Manfrotto 055B/ RC128, Manfrotto 028B/ Stellarvue M2C/ Argo Navis
Light Benders: 2” Astro-Physics MaxBright, 2” Stellarvue Deluxe, 2” TAL/ NPZ dielectric, 2” Baader Amici prism, 2” Long Perng Amici prism, 2” Baader Herschel wedge, Vixen 1.25" flip mirror
Jewellery: Antares to Zeiss, now only slightly more than 1 person requires!
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