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Binotron-27 - That was it for me

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#1 Fogboundturtle

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Posted 22 February 2013 - 10:55 AM

Order has been placed. Order with the Lunt adapter and the D21 eyepieces. I was looking for setup that would work with all my scope but most of all for solar viewing. The binotron-27 did it for me.

I guess I'll know in 2 months whether I made a mistake or not.

#2 rockethead26

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Posted 22 February 2013 - 11:53 AM

I doubt you made a mistake. The Denks work well in my Lunt 60 solar scope, my f/4.4 dob and my f/7.5 refractor.

I ordered my Denks a few weeks before the Binotrons were announced, so I missed that opportunity, but I'm very happy with what I have.

#3 Mauikj

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Posted 01 March 2013 - 04:48 AM

Hey there,

I dont have a lot of experience with binoviewers, I only had some Burgess ones I bought a few years back that were OK for solar but not really high quality. I got my Binotrons about a month ago and they are great ( I use them with the Denk 21's). The images merge perfectly and easily. What really impresses me how comfortable it is to view through them. I just see more than I do through a single eyepiece of the same power. I just got in form viewing Jupiter and is was awesome, even with marginal conditions. You are going to love them!

#4 ohioalfa64

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Posted 02 March 2013 - 05:26 PM

I ordered the Binotron-27 for my Dob and 150mm Mak f/12. Which diagonal do I need to use for these Binos? Can I remove the power-bar from the Bino and still focus if I use a Baader Prism diagonal? Sorry if this off topic.

#5 Never2Busy4You

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Posted 03 March 2013 - 09:00 PM

Any 2" diagonal should work with the Binotrons, and 1.25" diagonals should work if you get a 1.25" nosepiece. They should come to focus with your Baader prism diagonal with or without the Power x Switch, but without it you lose the ability to get Barlow & Reducer modes out of the same pair of EP's, so I would leave it on. YMMV.
Enjoy them either way.
I am very pleased with them so far, and the ability to collimate them for a perfect merge myself is just fantastic.

#6 faackanders2

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Posted 04 March 2013 - 08:11 PM

Any 2" diagonal should work with the Binotrons, and 1.25" diagonals should work if you get a 1.25" nosepiece. They should come to focus with your Baader prism diagonal with or without the Power x Switch, but without it you lose the ability to get Barlow & Reducer modes out of the same pair of EP's, so I would leave it on. YMMV.
Enjoy them either way.
I am very pleased with them so far, and the ability to collimate them for a perfect merge myself is just fantastic.


I don't have an SCT, but I have seen others write that for SCTs 1.25" diagonals are preferred due to their shorter length than 2" minimizing the loss of effective aperture.

#7 Never2Busy4You

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Posted 04 March 2013 - 11:30 PM

The shorter length of the 1.25" vs the 2" diagonal helps if the scope has a limited amount of back focus, most standard design SCT's don't have a problem with back focus since the mirror moves back and forth when focusing. The poster mentioned using a 150mm MAK, however some refractor users may find a great benefit for the shorter light path through a 1.25 diagonal. I am not familiar with aperture loss due to using a 2" diagonal, can you explain this for me, or have a referance link? I'm always interested to learn new things.
Thanks,
Jeffrey G.

#8 GlennLeDrew

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Posted 05 March 2013 - 05:22 AM

Jeffrey,
The aperture loss referred to applies only to telescopes having moveable primary mirrors for focusing (or, in general, systems which have variable separation between mirrors, both of which have optical power [not flat]). when the focus must be set so as to place the focal surface beyond some particular distance beyond the rear of the scope (as when one or more sizeable accessories 'eats up' lots of optical path length), the light cone for on-axis imagery will be clipped by the innermost opening if the primary baffle.

#9 Never2Busy4You

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Posted 09 March 2013 - 02:31 AM

Glen,
Thanks, I understand. I would think that in most cases it would be more accessories than just a 2" diagonal, or very dependent upon the design of the system.
Is there a definitive way to verify if there is an amount of aperture loss?
As an example,
I have been using a Denkmeier R2 Diagonal (it's a 2" diagonal that has a power switch on each side of the mirror housing) with the Denk II & Binotron-27 Binoviewers on a CPC800. I just purchased the CPC1100 & am looking forward to trying the combination on it as well. Visually I have not noticed any difference between using the R2 Diagonal, or a WO 2" Diagonal with the Binoviewers so this never crossed my mind.
Is there a way to measure if the aperture is being reduced by the longer light path of the R2, over the standard 2" version, or a difference between either of them over a 1.25" diagonal?
Thanks,
Jeffrey G.

#10 faackanders2

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Posted 09 March 2013 - 01:44 PM

Glen,
Thanks, I understand. I would think that in most cases it would be more accessories than just a 2" diagonal, or very dependent upon the design of the system.
Is there a definitive way to verify if there is an amount of aperture loss?
As an example,
I have been using a Denkmeier R2 Diagonal (it's a 2" diagonal that has a power switch on each side of the mirror housing) with the Denk II & Binotron-27 Binoviewers on a CPC800. I just purchased the CPC1100 & am looking forward to trying the combination on it as well. Visually I have not noticed any difference between using the R2 Diagonal, or a WO 2" Diagonal with the Binoviewers so this never crossed my mind.
Is there a way to measure if the aperture is being reduced by the longer light path of the R2, over the standard 2" version, or a difference between either of them over a 1.25" diagonal?
Thanks,
Jeffrey G.


I supposed you could draw out the light cone path, but with an SCT you would need to know where the focused mirror position would be (so it is not as easy as a Dob which just has the eyepiece move for focus.

#11 ohioalfa64

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Posted 09 March 2013 - 08:08 PM

While waiting for my Bonotron 27, I have been shopping for eyepieces for its use. Is this an amateur's approach? Should I just buy the extremely expensive Denk 21s? I have so far Nagler 11mm T5s, Vixen LNV Langanum 17s and one of two require 24mm Panoptics. I figure I can always sell what I don't use. Similarly I am looking at WO 7.25-22mm zooms. Am I all wet? Would Denk 14s or Denk 21s really be BETTER for the new Binoviewer?

#12 Mauikj

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Posted 09 March 2013 - 08:19 PM

Hey ohioalfa,
I can't say if other eyepieces are better or a better value than the Denks, but I figured Russ would optimize them for the Binoviewers so when I ordered my Binotron I got a set of the 21's too. With the powerswitch I get a great range of magnification and the quality is first rate. Again, I can't compare them but I can say I'm really happy with them (plus they are not too heavy so they don't add a lot to the Binoviewer's weight).

Good Luck - you will love your binotrons!

#13 rockethead26

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Posted 09 March 2013 - 08:58 PM

If someone wouldn't mind measuring, what is the housing diameter on the Denk 21s?

#14 Mauikj

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Posted 09 March 2013 - 09:49 PM

I get 1 3/4 inches. A tiny bit more if you count the rubber grips on the barrels.

#15 johnnyha

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Posted 09 March 2013 - 10:03 PM

alfy - congrats I am also waiting on the B27s.

I would recommend getting a second Pan 24 since you already have one. I would recommend them anyway over the Denk 21s. The Pan 24 will give you the largest FOV possible with the B27s and they are considered to be THE widefield eyepiece of choice for binoviewing.

With the 3X Powerswitch, the 11T6 makes a perfect jump from the highest setting with the Pan 24s, so it's not a bad choice either and in fact I loved mine when I had them and the only reason I now have the 13T6s is they are slightly physically smaller. But if you go by mag jumps with the Powerswitch, the 11T6 is the logical choice to go with the Pan 24s.

#16 rockethead26

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Posted 09 March 2013 - 10:10 PM

I get 1 3/4 inches. A tiny bit more if you count the rubber grips on the barrels.


Thanks! I'm trying to see if they will work for me.

#17 beatlejuice

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Posted 10 March 2013 - 12:31 AM

I got a pair of 25mm Sterlings about a year ago in anticipation of a future bino purchase. I really like them mono and figure to start with them and see about additions after I get my Binotron-27's, hopefully soon(7 weeks now)

Eric

#18 faackanders2

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Posted 10 March 2013 - 04:45 PM

alfy - congrats I am also waiting on the B27s.

I would recommend getting a second Pan 24 since you already have one. I would recommend them anyway over the Denk 21s. The Pan 24 will give you the largest FOV possible with the B27s and they are considered to be THE widefield eyepiece of choice for binoviewing.

With the 3X Powerswitch, the 11T6 makes a perfect jump from the highest setting with the Pan 24s, so it's not a bad choice either and in fact I loved mine when I had them and the only reason I now have the 13T6s is they are slightly physically smaller. But if you go by mag jumps with the Powerswitch, the 11T6 is the logical choice to go with the Pan 24s.


+1 Most like the wider view 24mm Panoptics the best with binoviewers. I have 14mm 82 AFOV ES but use the 24 Pans much more. Power switches help get highr powers with my Dob.

#19 Mike Harvey

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Posted 10 March 2013 - 09:57 PM

While waiting for my Bonotron 27, I have been shopping for eyepieces for its use. Is this an amateur's approach? Should I just buy the extremely expensive Denk 21s? I have so far Nagler 11mm T5s, Vixen LNV Langanum 17s and one of two require 24mm Panoptics. I figure I can always sell what I don't use. Similarly I am looking at WO 7.25-22mm zooms. Am I all wet? Would Denk 14s or Denk 21s really be BETTER for the new Binoviewer?


If you bothered to do your own homework, you'd find that the Power-x-Switch eliminates the need for as many eyepiece pairs as other binoviewers.
I prefer the 21 Denks and, except for very high power use, they stay in the unit perhaps 75% of the time. For those "higher powers", I prefer Naglers simply for the larger field of view.



#20 Never2Busy4You

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Posted 11 March 2013 - 12:03 AM

+1

#21 Geo557

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Posted 15 March 2013 - 12:04 AM

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#22 Fogboundturtle

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Posted 15 March 2013 - 09:06 AM

Geez. This is only a binoviewer. No need to get all emotional and such. I took the denk 21 eyepieces because it calibrated to be used with the binoviewer.

I am not working for or paid for by DenkMeier.

#23 teskridg

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Posted 18 March 2013 - 04:19 PM

I use the Earthwins with power x switch and an 11" SCT. I can't say I notice reduced aperture/resolution with the lowest power position, but 24mm Panoptics and 32mm Plossls do vignette somewhat in the reduced, lowest power x switch position. This is not the case with 30mm Plossls and I would expect there would be no vignetting with the 21mm Denkmeier eyepieces also. This vignetting isn't too disagreeable but it is present. Tim

#24 GlennLeDrew

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Posted 18 March 2013 - 07:33 PM

If one has any doubts about aperture loss, there are two ways to check.

1) The flashlight test. With eyepiece installed and focused at least near to infinity, shine a bright, compact light source straight into the eyepiece from a distance of a foot or two. Measure the diameter of the circle of light emerging out the front end.

An alternative: install a short focal length eyepiece so as to get an exit pupil Of about 1-2mm. Shine a green laser straight into the exit pupil, with the laser housing in contact if you wish. You will likely have a brighter circle of light to measure the diameter of. If the aperture is not fairly come telly illuminated at once, your laser beam is of narrower diameter than the exit pupil; increase the magnification.

2) With eyepiece installed and focused at least near to infinity, look into the front of the scope. Note the small image produced by the eyepiece. Move your eye laterally until the *center* of that image just becomes clipped, either by a baffle or the primary's edge. If a baffle edge clips the image center before it has reached the edge of the primary, aperture loss is occurring.






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