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Yet another which binoviewer question...

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#1 dr.who

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Posted 10 November 2012 - 10:07 PM

Sorry about this folks. Did several search iterations on keywords for ES127 and binoviewer but didn't find the answer so hence my post...

I would like to get a binoviewer that will work with my ES 82* EP's, my ES 127 APO, and my Celestron C11. Ideally I would be mating up a pair of 14 or 11mm as well as 6.7mm's. Icing on the cake would be being able to use all of my EP's with it including the 18mm 2" ones (not the 24's they would be just too darn big).

What would you recommend in terms of viewers that are under $600 US in price?

Thanks!

#2 Grandpa Jim

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Posted 10 November 2012 - 10:44 PM

I can't really address the EP issue, but I am convinced that the BEST binoviewers in the medium price range are the "Siebert Optics" BN-25's. They are comparable to the Baader Maxbrights, and are a bit better made in my estimation. Call Harry Siebert & check it out.......he is very nice to work with.

http://www.siebertop...inoviewers.html

I ordered a pair for myself but had to cancel them due to a life circumstance....... :bawling:

#3 Eddgie

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Posted 10 November 2012 - 11:12 PM

You have many options.

In your price range are the Baader Maxbrights and Seiberts, but also you can get the Denkmeier Standard bino head, and you may not want to dismiss this.

The price most people see when they look at the Denkmeier is for the "Supersystem". They also sell the bino heads "Ala carte." The Ala Carte option is about $500 for just the Binoviewer head.

The clear aperture of the Denks is 26mm which is the largest for any binoviewers in your price range.

The Baader Maxbright is attractive because you can keep the light path short using the Baader Prism diagonal. This is important because it determines how much magnification you will need to get your refractor to focus if it does not reach focus with the binoviewers. Many won't focus using a standard 2" diagonal, but just about any refractor that can reach focus with a 2" diagonal can reach focus with the Maxbright, T2 diagonal, and 1.7x GlassPath corrector.

For the price of the Denkmeier head, you can get a complete Baader Maxbright with your choice of 1.25" or 2" nose and your choice of 1.3x (works at 1.5x) glasspath adapter, 1.7x, or 2.7x GPC and the T2 diagonal!

The Maxbright does not have as much clear aperture as the Denks or the Seiberts, and the Maxbrights do not have collets. It uses three screws in each barrel to hold the eyepeices. The Denk uses compression type collar which makes changing eyepeices easy.

The Black Knights split the difference. You get 25mm clear aperture (more than the Maxbrights, less thand Denks) and you can get a compression type holder (though I don't know if this is standard or an option. The web page is not clear on this).

If the only thing you need is the binoviewr head, then the Seiberts look like a great deal.

If you want something with the most flexibility for different scopes, the Maxbright is appealing.

The Denks will give the widest true field, but options to keep the light path short are limited, and this means that it may not work in the refractor without spending more for an OCS (or just use a barlow), and the build quality of the Denks is very nice.

None of these will work with 2" eyepeices.

The Maxbright will give you the best chance of getting lowest power possible from your refractor.

All of them will work fine with your C11 even using a 2" diagonal.

#4 dr.who

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Posted 11 November 2012 - 12:06 AM

Thank you gentlemen! It sounds like it is a choice between the Maxbright and the Black Knights with the BK's being the better of the two... Is that a fair statement?

Oh and the 2" EP was a nice to have not a must have.

#5 Astrojensen

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Posted 11 November 2012 - 03:28 AM

your choice of 1.3x (works at 1.5x) glasspath adapter, 1.7x, or 2.7x GPC


Just a note of correction:

The 1.25x GPC works as 1.25x when in the top of the prism diagonal, 1.3x when in front. The 1.7x works as 1.5x when in the top, 1.65x when in front. The 2.6x GPC I've yet to measure accurately, but seems close to 3x when in front of the prism.


Clear skies!
Thomas, Denmark

#6 Bob S.

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Posted 11 November 2012 - 06:46 AM

Thank you gentlemen! It sounds like it is a choice between the Maxbright and the Black Knights with the BK's being the better of the two... Is that a fair statement?

Oh and the 2" EP was a nice to have not a must have.


Carson, What you get additional with the Siebert's is direct customer service from the fellow who makes them. He offers free lifetime alignment should they ever need it and he has a tremendous amount of customizable options if you choose to use the binoviewers in other telescopes. Bob

#7 tomcody

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Posted 11 November 2012 - 05:06 PM

+1 for Maxbrights (the most versatile system with all the T-2 options).
One point, you may find eyepieces between 15mm and 24 mm the most usable and comfortable. I prefer 19mm's for best viewing comfort and do not use any pairs below 13.8 at all ( even though I own several pairs down to 7mm Naglers as they are just not easy to look through like the longer focal lengths).
Rex

#8 Eddgie

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Posted 11 November 2012 - 06:04 PM

Yes, you bring up a good point. The OP asked about using a kind of short focal lenght eyepiece, and with binoviewers, I think the better approach is to Barlow for highest powers rather than use short focal length eyepeices.

#9 orion61

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Posted 14 November 2012 - 08:33 PM

Heck I have had good luck with $119.00 Arcturus.
I dropped my Nikons and messed them up, I couldn't afford anything else but hoping against hope I ordered them.
I have ended up tearing into the Nikons and realigning them.
I tested them and decided to give the Nikons to my best friend who had some horrible medical issues and no way could afford any. We are both happy, no image merging issues and work well with my 4 matched ocular, oops scratch that 3 pair (Gave Tom a pair of 18's and a Barlow)
Bino Viewers are great and EVERY serious Lunar/Planetary viewers NEED a pair.
I like the fact they got rid of the set screws on their new model, and include a nose piece barlow now!
which ever you get good luck, try putting the Moon at the edge of view and shut off the motor drive, enjoy the "Space Walk"

#10 dr.who

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Posted 23 November 2012 - 07:33 PM

Right. So I was JUST about to pull the trigger when something tickled my brain...

I had planned to use the 14mm ES 82* EP's in a BV. And after looking at the Siebert's and the Baader's and then talking to the gentleman who makes them I came down on the side of the Maxbrights due (unfortunately) to cost. The Siebert's came out at about $800 with all the extra kit I needed whereas the Maxbrights are only $340 with everything I need.

After more reading I see cases were people don't use a glasspath adapter and others where they do. So my first question is with my scope having a backfocus of 120mm and the bino's being 110 do I need a adapter? My second question is if I do and it's the 1.2 then I would be taking those 14mm ES EP's and effectively barlowing them to 11.66~, correct?

Thanks again for the help!

#11 dr.who

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Posted 08 January 2013 - 02:39 PM

Update-

Woodland Hills Telescope and Darkroom (my local shop) was kind enough to lend me a Denkmeir to test with including the 1.2x OCS. Last night at about 8:30 I saw the clouds clear and went out with the 127mm to test. These are my results.

I looked at (a small portion of) the double cluster, Orion nebula, and Jupiter.

I used two 11mm ES 82* EP's. I am using 11's because I don't have any other 1.25" EP's to test with at the moment.

I used an 8.8 mm ES EP as the starting point to make sure the objects were centered up. The reason for the 8.8 was that the ES 11's divided by 1.2 equals 9.16mm so the closest EP I had was the 8.8.

I tested the BV's with and without the OCS. I did this because the problem I was having with the Baader's were too little infocus whereas with the Denk's I was reaching focus with the focuser out almost half it's length so I was hoping for focus without the OCS.

I was able to reach focus with the OCS in the nosepiece of the stock ES diagonal with the focuser out about 4.5 inches. I was not able to reach focus without the OCS. This was expected but to be thorough I wanted to test it.

My results with the ES 127 are that the views of the DSO's were like I was looking at something in 3D. This part was fantastic. What was not fantastic was that the objects were so dim that it really took away from the experience. To the point where the 3D effect was overshadowed by how dark the views were making a BV a non-starter for this OTA for DSO viewing. Yes I understand why there was a light loss.

On Jupiter it was very nice and had the same 3D effect with acceptable levels of light loss. Were I primarily a planetary viewer a BV in this OTA would be a big win.

I plan to repeat this test this evening (clouds willing) in the C11. My expectation is that the views will be brighter. My hope is that they will be bright enough to justify a BV for me for this OTA.

More (hopefully) to follow.

Thank you all again for your help on this!

#12 mikey cee

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Posted 08 January 2013 - 06:03 PM

Doc....It's seems odd to me however everyone sees things differently I guess. To me I can see little or no light loss even tho' your brain recaptures "some" of the 50% light loss. Maybe you see it more with 5" than I do with 10". I don't know. All I know is it's bino city from here on out ....no reservations period! :grin: Mike

#13 dr.who

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Posted 08 January 2013 - 06:53 PM

Hey Mike-

My guess would be that the 5 extra inches and "slower" scope you have make a big difference. I am expecting something similar in the C11 with the 6" of extra aperture and one+ full F stop up. Hopefully I will have success tonight.

#14 Eddgie

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Posted 09 January 2013 - 09:08 AM

First, I am confused. You said that you used the Denkmeier with a 1.2 OCS?

I don't recall Denkmeier making a 1.2 OCS.

And you may be confused (as I was) about the Denkmeier "Stated" power factors (which I think are misleading on their web page).

If you were using a Denkmeiser Supersystem with a low power arm, the low power only gives 1.3x, but... Wait for it... Wait for it... This is only when used with a Denkmeier diagonal (or diaognal with similar nose threads).

If you just screw the OCS on to the nose of most diagonals, the magnification factor is more like 1.4x. To get the 1.3x that they state on the web page, you have to use a speciclal configuration where the nose of the diagonal is unscrewed and the OCS screws directly into the frong of the diagonal, than an extension is used in front of the OCS to give the lenght of a standard diagonal nose.

This means that if you were using a supersystem on your own diagonal, your powers were much higher than you thought, and the exit pupil would have made the view dimmer than you were expecting becaues the power was likely higher than you though.

But even with this, I found the Supersyestm image to be so dim in my 6" APO that I was totally unsatisfied with it.

Not that the Baader was much better because to reach focus, I had to use the 1.25X GPC in a 1.5x configuration to reach focus, so the power was even higher.

And this is what put me off of binoviewing with the 6" APO. The scope give magnificent wide field views using Naglers, and the loss of brigtness with the binoviewers and the restriction to get low power using 68 degree eyepecies (and the 24mms don't work with the low power arm, so you are forced to use 19mm Pans with the low power arm in) made the whole thing unappealing to me.

What can you do about it? Learn to love narrow field eyepieces.

Consider getting a pair of 40mm (I just did) or 32mm Plossls for the dimmest objects.

Adjust your eyepeices to make sure you are using the exit pupil you think you are using >>> If you were were expeciting that the magnification was 1.3x and it was really 1.44x (like mine was), then step down a notch to restore brightness.

Bottom line though.. In smaller scopes, the dimming can indeed be such that it makes a difference.

Even using 13mm eyepecies in my C14, a power that I used to use a lot with monovision for planets, I find the image to be getting dim enough in binoviewers (no OCS) to be hard to use.

I think you will have better luck with your C11, but again, learn to love narrow field eyepeices and slightly smaller image scales....

#15 dr.who

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Posted 09 January 2013 - 02:55 PM

First, I am confused. You said that you used the Denkmeier with a 1.2 OCS?

I don't recall Denkmeier making a 1.2 OCS.


Pardon me Edgie I misspoke. Per their web page it is called a format correcting system. Per my local shop it was 1.2x power corrector.

And you may be confused (as I was) about the Denkmeier "Stated" power factors (which I think are misleading on their web page).

If you were using a Denkmeiser Supersystem with a low power arm, the low power only gives 1.3x, but... Wait for it... Wait for it... This is only when used with a Denkmeier diagonal (or diaognal with similar nose threads).

If you just screw the OCS on to the nose of most diagonals, the magnification factor is more like 1.4x. To get the 1.3x that they state on the web page, you have to use a speciclal configuration where the nose of the diagonal is unscrewed and the OCS screws directly into the frong of the diagonal, than an extension is used in front of the OCS to give the lenght of a standard diagonal nose.

This means that if you were using a supersystem on your own diagonal, your powers were much higher than you thought, and the exit pupil would have made the view dimmer than you were expecting becaues the power was likely higher than you though.


This was a used "big easy". Would that make a difference? Either way though it did work and worked well for 3D but as you note based on the correction misunderstanding on my point that would have made a difference! Taking it from a 9mm to a 8.4 at 1.3x and a 7.8mm at 1.4x.

But even with this, I found the Supersyestm image to be so dim in my 6" APO that I was totally unsatisfied with it.

Not that the Baader was much better because to reach focus, I had to use the 1.25X GPC in a 1.5x configuration to reach focus, so the power was even higher.

And this is what put me off of binoviewing with the 6" APO. The scope give magnificent wide field views using Naglers, and the loss of brigtness with the binoviewers and the restriction to get low power using 68 degree eyepecies (and the 24mms don't work with the low power arm, so you are forced to use 19mm Pans with the low power arm in) made the whole thing unappealing to me.


As it was to me. And from what you mention here it looks like my findings parallel yours regarding use in a small aperture APO.

#16 dr.who

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Posted 09 January 2013 - 03:04 PM

Update Part II-

Based on the information gleaned from Eddgie's post regarding the actual magnification of the Denkmeir Format Correcting System (words taken from their web page to describe it) being higher than I was expecting it does explain the loss of light in terms of views. Per Eddgie if it's not used in a Denk diagonal then it would be a 1.3x or even 1.4x as opposed to the 1.2x I was expecting. Thus moving the EP's from a 9mm to an 8.4 or even 7.8.

Regardless it was still an unsatisfactory view in the APO.

I did test it last night with my 11" SCT. It was an abbreviated test with me looking at the Orion Nebula, Rigel, and Jupiter due to family obligations and clouds rolling in.

The C11 handled the Denk's much better than the ES 127mm in terms of brightness with much less light loss though it was still noticeable and did take away from the viewing enjoyment. Focus was easy to find and overall I think that were I to go down the BV path the only way I would use a pair was if it was on a 8" SCT or larger due to loss of light.

#17 Mike B

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Posted 11 January 2013 - 12:49 PM

...the only way I would use a pair was if it was on a 8" SCT or larger due to loss of light.


The *only* BVing i have done is with my former scope, a 10" SCT, and my current scope, a 15" Dob; i cannot address the "light-loss" effect at smaller apertures.

Yet BVing the 10" SCT, versus "cyclops" mode, i really didn't see a huge brightness difference. But i'm coming to suspect this sensation may vary among observers... perhaps some experiencing the "additive" effect of TWO eyes moreso than others?

Do be aware, tho, the BVers in an SCT- the backfocus distance being so great- the SCT optics will likely be functioning closer to F11.5... *not* their advertised F10. You may wish to drift-time your SCT+BVer system to see what it is, specifically, for your scope. Can make a big diff in EPs selected!

Enjoy!
:grin: mike b

#18 teskridg

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Posted 14 January 2013 - 08:26 PM

You want to see the brightness difference? Try viewing the moon in single and then bino modes. I think you'll notice that with monovision, the moon is almost painfully bright; it becomes tolerable with the binoviewer. That's why if you become a binoviewing junkie like I am, you may get a severe case of aperture fever because increasing aperture copensates for the loss of light caused by the binoviewer. To put this another way, I think the binoviewer effectively reduces the primary's aperture somewhat. I don't think this is a deal killer for the binoviewer as long as one understands the trade-off and especially if one is able to increase aperture to compensate. Tim






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