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Edmond 28mm RKE's in WO binoviewer?

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#1 mg73

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Posted 05 July 2012 - 07:09 AM

How well do you think a pair of Edmond 28mm RKE's would pair up the a WO binoview in a Celestron Nexstar C11? (F/10)?

How do you think they would compare or be different from the WO eyepieces that come with the binoviwer?
Thanks for any comments.

#2 EdZ

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Posted 05 July 2012 - 01:50 PM

just to point out

a binoviewer in an SCT won't be f/10, it varies with the scope. Might be f/11 in your C/11. It's f/12.5 in my C6 and about f/11-f/12 in my C8.

edz

#3 pftarch

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Posted 05 July 2012 - 02:24 PM

I don't have a C11, but I routinely binoview my 28 RKE's on my 10" dob, my 5" mak, and my 80mm apo refractor. I use them in both a WO binoviewer and an Earthwin bino. (Admittedly, they spend most of their time in the Earthwin).

I haven't done the "coke vs pepsi" challenge vs my 20mm WO eyepieces so I can't speak directly to that. I can share some thoughts on binoviewing the Edmunds so you can go into this with "both eyes open". (Please note that I LOVE binoviewing with the RKE's, BUT, they present some unique challenges. I am willing to put up with it, others are not (and I can see why they wouldn't). I believe that the famous EdZ, who posts here often, and who's advice I have followed often, is not a fan of binoviewing the 28 RKE's.

The RKE's blackout unless you get your head JUST right even in mono mode. This gets even worse when you are trying to line up two at once. I find it critical to get your IP adjustment perfect AND VIEW SEATED. You move your head even a microscopic amount and you lose the view.

The RKE's measure eye relief in yards, not mm. This is great for glasses wearers AND for minimizing eyepiece fogging, BUT, it's not so great when you have a streetlight nearby, a neighbors porch light, etc. You can address this with the rubber boots that come with them, but that eliminates the "floaty" effect and that's half the reason I use them. I tend to cup my hands around the eyepieces when viewing, others use hoods.

Scanning the sky with the RKE's is a different process for me. Instead of slowly moving across the sky and watching the stars go by, I move one field over, stop, reaquire the view, move one field over, stop, reaquire the view. (This isn't so bad on my tracking GEM, but in manual alt az on the dob and refractor it's how I have to do it.)

I prefer the RKE's to my WO 20 mm for three main reasons, in the following order of importance:


1. Maybe it's just me, but I find the general view through the RKE's to be crisper than any of my other eyepieces. I see more detail on deep sky stuff and more detail on planets. (Please note that I don't own any premium eyepieces, but in my opinion, the RKE's show significantly more detail, even in the center of field than the WO 20's, or ANY of my other eyepieces.).
2. On my sub f5 dob (which is my preferred scope), the edge of field "mushiness" isn't visible to me on the RKE's, whereas it is on my WO 20mm. This is advantage lessens as you increase focal ratio.
3. The "floaty effect", even with the binoviewers, is awesome.


YMMV, and you may want to try before you buy. I would caution you that it took me a few days to get comfortable bino'ing the RKE's, so your first crack at them may be less than ideal.

Much like classic european sports cars and high maintenance feisty woman, binoviewing the RKE's takes more than minimal work to enjoy, but when it's right, there is nothing better in the world, and you forget all the struggles you went through to get that joy when you do get it. I really enjoy my RKE's, and I love my feisty bride of 13 years, and I drive a minivan, so I can't comment on the european sports car thing.

Good luck and keep us posted on how it goes for you.

Peter T.

#4 pftarch

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Posted 05 July 2012 - 02:49 PM

I believe that the famous EdZ, who posts here often, and who's advice I have followed often, is not a fan of binoviewing the 28 RKE's.


Hey Ed! While I was busy rambling in my post, you posted before I hit submit.

(And I meant what I said about valuing your advice.)

Peter T.

#5 orion61

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Posted 05 July 2012 - 11:26 PM

I have a complete set of Edmund eyepieces that I use,
Binoviewers are not good for DSO's They ar faves for sharpness in the center of view, I grew up with 40 degree FOV eyepieces,
I love 15mm and 12mm RKE eyepieces.. the best view I ever had of Jupiter was with my C8 and 15mm RKE's with Lunar may be ok with 28's Just remember many like Rke's for COV
Center of view brightness and sharpness.

#6 k5apl

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Posted 06 July 2012 - 01:30 PM

I have a pair of 28mm RKEs and a Baader binoviewer. I do not
like them for binoviewing with my manual alt-az mount. others have said it, about having to be in the exact spot due to very long eye relief. View ok, but really like my
Sterling 25mm's for binoviewing, and RKE 28mm for mono.

Wes

#7 GlennLeDrew

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Posted 07 July 2012 - 01:48 AM

Peter,
Why would the famous 'floaty' effect of the RKE 28 be diminished by using eyecups? Is it because the 'floaty' effect requires to also see the background apparently surrounding the narrow rim of metal surrounding the eye lens? If so, then the demand to perceive the 'floaty' effect is actually detrimental, for the non image-forming light can only interfere. When observing dim, low contrast scenes, ALL extraneous light should be assiduously and totally blocked from view. I have for my home-made binocular a couple of eyepieces which also offer the same kind of 'floaty' effect, but even when out at a very dark site I find that I must employ a dark hood that wraps around the eyepieces sufficiently so as to fully block the view of the entirety of the surrounds and background. Any light other than that making up the image in the eyepiece is intrusive, distracting and injurious to the detection of the faint targets I strive to see. In short, I strive to eliminate the perception of the 'floaty' effect, by permitting only the image itself to be seen in splendid, isolating darkness.

#8 Jeff B

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Posted 08 July 2012 - 08:57 AM

How well do you think a pair of Edmond 28mm RKE's would pair up the a WO binoview in a Celestron Nexstar C11? (F/10)?

How do you think they would compare or be different from the WO eyepieces that come with the binoviwer?
Thanks for any comments.


Without any corrector/barlow in the light path, they will work just great and yes you really need to position your head just right, but the "floating" affect is enjoyable for me.

Trouble is, if there is a corrector/barlow in the WO's light path, it will give too much eye relief to an eyepiece that already borders on too much.

Actually, I find the 28MM Edmund Plossl the better choice for me as it can readily take the barlow and focal reduction of my Denks in stride but still provide a big chunk of that floating effect.

Jeff

#9 davidpitre

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Posted 08 July 2012 - 03:51 PM

Much like classic european sports cars and high maintenance feisty woman, binoviewing the RKE's takes more than minimal work to enjoy, but when it's right, there is nothing better in the world, and you forget all the struggles you went through to get that joy when you do get it. I really enjoy my RKE's, and I love my feisty bride of 13 years, and I drive a minivan, so I can't comment on the european sports car thing.

Excellent analogy, and my priorities mirror yours. I put out the effort for my crazy beautiful fiesty woman and binoviweing 28mm RKEs, but I was not willing to put out the effort required of a high maintenance sports car. I'm cool with my old truck.
As to the diminished "floating " effect of the RKEs, I have not tried eye-guards, but cupping my hands does not lessen the experience.

#10 ckwastro

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Posted 09 July 2012 - 12:00 PM

I use the 28s in my Denk with the Mewlon and they are very nice. As mentioned before, eye-placement with the 28s is fairly critical, but the rewards are well worth it. The RKE line has become my favorite eyepieces for lunar observing, as well as Saturn, and emission nebulae for deep-sky. I also have sets of the 21s and 15s, both of which are very nice.

As an aside, if you decide to pick up any others from the RKE line be wary of the stated eye-relief, which is far different from the usable ER for those of us with glasses. The 21s have 18.8mm ER, and the 15s have 13.4mm, however the eye-lens is sunk deep within the housing. Using the depth gauge on my caliper to measure the 21 and 15, the eye-lenses are sunk 6mm and 8mm respectively from the upper rim of the housing. The usable eye-relief is down to 12.8mm and 5.4mm. Fortunately, with the Mewlon being F/11.5, and using the 1.2x corrector with the binoviewer (and the power-switch for 2.4x), the exit pupil is small enough with these two to eliminate the need for my glasses. Without glasses I find the 21 to be very comfortable, and the 15 is workable. However I doubt I'll be able to use them effectively in the Stowaway, except on the 2.4x setting. You would probably be OK with these two in your SCT.

#11 awaitsclearskies

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Posted 14 July 2012 - 12:18 AM

I use the 28mm RKE's in a Denk Deepsky binoviewer with my C9.25. The image they give are like no other eyepieces, they are without a doubt my favourite set. As for how they might measure up to the WO ep's I can't say, but they are noticeable sharper on axis to the set of Antares 70 degree ep's that came with my Denk.

#12 pftarch

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Posted 21 July 2012 - 02:19 AM

Peter,
Why would the famous 'floaty' effect of the RKE 28 be diminished by using eyecups? Is it because the 'floaty' effect requires to also see the background apparently surrounding the narrow rim of metal surrounding the eye lens? If so, then the demand to perceive the 'floaty' effect is actually detrimental, for the non image-forming light can only interfere. When observing dim, low contrast scenes, ALL extraneous light should be assiduously and totally blocked from view. I have for my home-made binocular a couple of eyepieces which also offer the same kind of 'floaty' effect, but even when out at a very dark site I find that I must employ a dark hood that wraps around the eyepieces sufficiently so as to fully block the view of the entirety of the surrounds and background. Any light other than that making up the image in the eyepiece is intrusive, distracting and injurious to the detection of the faint targets I strive to see. In short, I strive to eliminate the perception of the 'floaty' effect, by permitting only the image itself to be seen in splendid, isolating darkness.


Glenn,

I was ready to write a post back to you about how the floaty effect was worth the slight interference from stray light and how much I hated using the rubber boots blah blah blah.

But, because of your post, I gave the boots another shot. Come to find out, using the rubber boots on the 28's doesn't bother me as much now as when I first got the eyepieces. In fact, it makes it a whole lot easier to keep the proper head position. Mind you, the floaty effect is gone, but, and this has changed since I first got the RKE's, the floaty effect isn't the main reason I like the eyepieces. (On my list above it is in third place of the three reasons I like the RKE's, whereas when I first got them it would have been in first place.) I must note that with my not so dark viewing location I can't get the "totally black" scenario you mention, but it was nice not having to constantly cup my eyes over the lenses to block out streetlights and I didn't have to concentrate as much on holding my head in the right spot.

Thanks Glenn for reintroducing me to the rubber boots. Even without the floaty effect, these are some great eyepieces. The views I had tonight of both Andromeda and the Dumbell were spectacular and without blackouts.

Peter T.

p.s. for those just getting the RKE's, enjoy the floaty effect in the beginning, it is still pretty cool. But after that, try the boots again, because that's pretty cool too.

#13 Starman81

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Posted 29 September 2012 - 05:20 PM

First light for BV'ing RKE's last night on the moon... Nexstar 8SE was not able to track (loose power pin), so I had to manually track the moon. Trying to keep the view was an exercise in futility! I was just not able to first of all get in the sweet spots of both RKE's and then hold it long enough for the images to merge, it just was not happening. I finally did get it, but it took a lot of effort. The effect and view once you do get it, is great, but that is one high-maintenance view! I love the RKE for monoviewing but I don't know if I can handle the drama of *two* high-maintenance feisty EP's at the same time!

I popped in the 25mm E-Lux's and they were 5x easier to use though not as exotic of a view as the RKE's. Still the automatic, effortless merging of the images and ease of holding the view with the non-tracking 8SE meant that the humble E-Lux's got all the BV'er time on this night.

I will give the RKE's another try as soon as I get my power pin issue fixed on the N8SE. I won't give up on them that easy.

#14 pftarch

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Posted 29 September 2012 - 06:22 PM

Starman,

I LOVE my RKE's, I LOVE binoviewing, but even I am not completely convinced of hand tracking bino'd 28 RKE's on an altaz mount other than a dob. (The dob is a piece of cake with a little practice.)

When your tracking is in place it should go smoother. But with or without tracking, if you're not sitting, it will be a struggle. If you were standing on your first try, please try it sitting down.

Did you get the rubber eyeguard boots with yours? As I said above, they make holding your head position MUCH easier (while seated). Downside, using the booties completely negates the floaty effect for me. But, as I said above, it turns out I love the RKE's even without the floaty effect. I leave the boots on mine now.

Good luck and keep at it. Once you get it it is pretty cool.

Peter T.

#15 Starman81

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Posted 29 September 2012 - 07:28 PM

Starman,

I LOVE my RKE's, I LOVE binoviewing, but even I am not completely convinced of hand tracking bino'd 28 RKE's on an altaz mount other than a dob. (The dob is a piece of cake with a little practice.)

When your tracking is in place it should go smoother. But with or without tracking, if you're not sitting, it will be a struggle. If you were standing on your first try, please try it sitting down.

Did you get the rubber eyeguard boots with yours? As I said above, they make holding your head position MUCH easier (while seated). Downside, using the booties completely negates the floaty effect for me. But, as I said above, it turns out I love the RKE's even without the floaty effect. I leave the boots on mine now.

Good luck and keep at it. Once you get it it is pretty cool.

Peter T.


Thanks Pete for the additional info. Forgot to mention that I was viewing seated--I never view standing after acquiring an adjustable observing chair earlier this year.

I only have one rubber boot for the RKE's (the one I bought new). So I cannot try the rubber boot idea. I am viewing with glasses (primarily) so the rubber boot might not work for me? Nonetheless, I am going to give it another shot soon, tracking or no tracking. Since it was only my 2nd time BV'ing I thought maybe it was due to inexperience that I was unable to hold the view. However, I disproved that notion instantly after putting in the E-Lux's.

As far as binoviewing with dobs, I don't want to derail this thread, but I never knew it was possible without moving your primary up until I read a few threads. I have questions around that--I will pm you Pete.

#16 Ira

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Posted 13 October 2012 - 06:32 PM

I just bought a pair of the 28mm RKEs from Surplus Shed while they were on sale for $35 each. I just couldn't pass them up. I also plan to use them with WO binos and my f6 5"APO on a tracking mount. I understand the comments about eye relief and black out. But what about vignetting with the narrow optical path of the WO binos. Is there much of that that I can expect?

/Ira

#17 EdZ

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Posted 13 October 2012 - 08:11 PM

I just bought a pair of the 28mm RKEs from Surplus Shed while they were on sale for $35 each. I just couldn't pass them up. I also plan to use them with WO binos and my f6 5"APO on a tracking mount. I understand the comments about eye relief and black out. But what about vignetting with the narrow optical path of the WO binos. Is there much of that that I can expect?

/Ira


The 28.7mm RKE has a 23.3mm field stop, so the starting maximum fov is 46.5°

I measured the actual full hard cutoff in the field of view using the 28RKE in both a C5 and an f/6 80mm refractor. There was a 3% loss in the C5 and a 4% loss in the 80mm. So not too much loss of field. I did not measure the extent of edge darkening of field.

#18 Ira

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Posted 13 October 2012 - 08:20 PM

Thanks, Ed. That's encouraging.

/Ira

#19 killdabuddha

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Posted 27 November 2012 - 02:24 PM


The RKE's blackout unless you get your head JUST right even in mono mode. This gets even worse when you are trying to line up two at once. I find it critical to get your IP adjustment perfect AND VIEW SEATED. You move your head even a microscopic amount and you lose the view.

The RKE's measure eye relief in yards, not mm. This is great for glasses wearers AND for minimizing eyepiece fogging, BUT, it's not so great when you have a streetlight nearby, a neighbors porch light, etc. You can address this with the rubber boots that come with them, but that eliminates the "floaty" effect and that's half the reason I use them. I tend to cup my hands around the eyepieces when viewing, others use hoods.

3. The "floaty effect", even with the binoviewers, is awesome.

Peter T.


:waytogo:

I think we purchased the last $62 pair. Used them these last several nights on the moon, with 13% filters and through rapidly movin cloud haze which lent remarkable effect. Contrast is amazing as it moves in and outa light. And yeah, was glad that my wife could acquire and hold the sweet spot. The moon looked like a huge Christmas tree ornament, or maybe one of those Christmas globes. Or the old RKO Radio Pictures logo. Really glad we took the leap here.

#20 Starman81

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Posted 28 November 2012 - 10:45 AM

I tried once binoviewing the RKE's in the WO BV'er but gave up as the image was tough to hold. I probably gave up too easily though. I was observing seated.

#21 killdabuddha

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Posted 28 November 2012 - 11:26 AM

I recoiled a bit from my surprise at how far back she was positioned. We'd hoped that they'd be popular outreach EPs, but this probably isn't realistic. But for us, we really do like the effect and will eventually try them on all the objects. Plus, after usin these, any other EP is a breeze. Training wheels with benefits :lol: Neither do we use the eyecups.

#22 ckwastro

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Posted 28 November 2012 - 02:42 PM

Glad you are enjoying the 28s in the binoviewer! Luna is fantastic with this configuration!

#23 Ira

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Posted 04 December 2012 - 06:59 PM

I bought a pair from Surplus Shed. Didn't believe what everyone said here about the view being hard to hold. Well, it is, even seated. The jury is still out on this for me. I think I would be happer with a mid-20mm wide angle pair, other than the RKEs.

/Ira

#24 DaveJ

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Posted 04 December 2012 - 09:26 PM

I bought a pair from Surplus Shed. Didn't believe what everyone said here about the view being hard to hold. Well, it is, even seated. The jury is still out on this for me. I think I would be happer with a mid-20mm wide angle pair, other than the RKEs.


If possible, get hold of a pair of 24mm Panoptics. They are just simply amazingly easy to use and with their 68 degree AFOV, provide the widest TFOV possible in a 1.25" binoviewer. Tele Vue has them marked down at the moment for their sale. Not exactly inexpensive, but worth every cent.

#25 Ira

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Posted 06 December 2012 - 09:23 PM

I have an old 22mm Panoptic. Would it work as well, assuming I can find a mate? Alot cheaper since I only need one, and it would be used.

/Ira






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