Binoviewer

[Neil]

G,day everyone, does anyone have an opinion on or has used a binoviewer , any advice or recommendations on particular brands or models would be greatly appreciated.

[gbeal]

This will bring a raft of opinions, and I'll kick it off with mine.
I have the Denkmeier Standards, bought about 4 years ago perhaps. Love them for lunar and solar use, mixed feelings with DSO's.
For solar I usually use them in my Zeiss AS63/840 Telementor. Gorgeous views.
Luunar is normally with the 10" f5 newt. Only eyepieces I have at present for them are a pair of old and not too pretty Celestron 20mm Erfles. Perfect.
It has been said that bino-viewers are kind to older and less flash eyepieces, and maybe there is some truth in this.
Depending on what scope(s) you are thinking to use one in, you may need an optical system to bring the focus point out. In my case with the newt I have the 2" OCS made by Denkmeier. I can also use this with a 2" diagonal and this is how I use it with the refractor. The 2" OCS gives either 1.3x or 3x magnification, and if I want any more I simply use the 2.5x or 5x Powermates (you could use any barlow).
Good luck, try a few first, as I know a couple of observing friends who either can't "merge" the views, or plain can't use one.

[wavelandscott (Scott)]

I have the Denkmeier "Big Easy" binoviewer...

I am not a "technical" observer but enjoy the "art" of viewing...

I like to use them on the moon and planets...DSO (deep sky objects) can be a bit dissappointing depending on the aperture of the scope that you are using.

I have used them in on my Skywatcher ED 80 and enjoy the daylights out of it on the moon...most planets are pretty cool too.

I have used them in an 8 inch Bintel (GSO) Dobsonian mounted Newtonian reflector...again the moon is glorious...Orion Nebula and a few of the other big name nebula are okay.

I have used them in my 12.5 in Discovery Truss style Dobsonian mounted Newtonian relector...DSO are better better than on the other two scopes but still not great...the views remind me of viewing DSO through the smaller scopes...

The DSO views are okay but not breathtaking...to me and in my opinion, the moon and planets are breathtaking...

As has been already noted, you will most likely need an OCS (depending on your scope) and some scopes have difficulty focusing with extensions for focuser tubes or an OCS...

I have 3 sets of eyepieces that I use...21 mm Denkmeier, 15 mm Televue Plossls, 8 mmm TMB Planetary...

(I will also now confess for the first time that I have ordered a pair of Denkmeier 14 mm even my wife does not know this information yet...and based on how nice the 21 mm Denks are these should be great...but the TV plossls do a really nice job too I was just in the mood to "upscale" a bit)...

I have not tried them yet for solar viewing but I imagine that they will work well with a properly filtered scope.

Again as noted previously please try some before you buy if possible...while I have not had any difficulties with merging, some people do.

I've enjoyed them because of the easy and comfortable view that they provide, I just get drawn into longer and longer watching thereby picking out more detail...

Clear Skies!

[astropolak (Joe)]

Hi
I thought I'll share my experience so far with Binoviewer - I have a Denk Big Easy.
Initially I purchased two sets of eyepieces for it - a pair of 20mm GSO Superviews and a pair of KK Erfle 20mm. I found the GSO's not meeting my expectations by a large margin.

The binoviewer does look and perform very well indeed but then again I did not have opportunity to compare it to other units.
I do have a complain or two about the Denk - in its OCS it uses BRIGHT lens retaining rings that are sure to reflect light and cause loss of contrast or worse. The bright retaining rings are used both in the barlow element as well as focal reducer. I have raised this with Denk - Denkmeier thinks that this is not a problem.

Nowhere on the web will you also see a mention that the Panoptic 24mm will vignette in this Binoviewer as it does - it is right on the margin but prevents you from seeing the field stop as a sharp ring.

I found the focal reducer element useless in planetary or Moon viewing - the rings cause so much reflections near the edge it is not even funny.

As for the Eyepieces both the Pan and KK produce spectacular viewing with the Pan clearly best eyepiece in the Bino.

I think the greatest untold story is the eventual cost of a binoviewer once you discover that you will need decent eyepieces all costing you double as you need pairs of them.

I use the Denk for viewing all objects and they do excel in Moon and planetary obsessing. I found them loosing a bit in sharpness and some loss of light on other objects but the ease of viewing and 3D effect more than compensates for it. Many people I am told do not look back and observe with a binoviewer only... I use the binos in a 10" SCT.

The bino weights about 1.5 KG with a pair of 24 Pans so make sure you can deal with that.

Overall I am very pleased with the solution but wonder if perhaps a lower cost Bino would work as good.

Joe

[wavelandscott (Scott)]

Originally Posted by astropolak

Hi

Nowhere on the web will you also see a mention that the Panoptic 24mm will vignette in this Binoviewer as it does - it is right on the margin but prevents you from seeing the field stop as a sharp ring.

Joe,

I think if you look on Cloudy Nights and some of the postings by Edz (I think that is his name) you will see that he has done a fair amount of work on this topic...From memory he has developed a spreadsheet that will predit/show where vignetting may occur with different binoviewers and eyepiece combinations...

Next time we are at the same place remind me to let you try the 21 mm Denkmeier eyepieces in your Bino and scope...They are a pretty special combination...

Cheers!

[Satchmo]

Originally Posted by astropolak

I use the Denk for viewing all objects and they do excel in Moon and planetary obsessing. I found them loosing a bit in sharpness and some loss of light on other objects but the ease of viewing and 3D effect more than compensates for it.

Joe , Thanks for the presenting the straight up reveiw. The loss of brightness on deep sky objects is of course because you are splitting the light of 10" SCT optics and getting the equivelent of two 6" telescopes, but not quite gaining back a 10" with the combination of two eyes. With a true binocular there are many other advantages in image processing.

I once compared the view through a 13" Newtonian fitted with $2000 Televue binoviewer against a farly crude 6" F8 Binocular Newtonian and decided the 6" binos won clearly on contrast and sharpness. Whilst Binoviewers are a really compact choice , I think as time goes on , the merits of even low cost 6" and 8" true binocular scopes built for under a $1000 will surface.

You are right about the eyepiece 'problem' Low quality eyepieces become even more obnoxious when one has both eyes to study the view with .

[Cec]

Hi Neil
I have the Denk "Big Easy" and use it with a pair of Televue Pans 19mm, as yet have not tried other eyepieces.
I have used both a 12inch dob and an 18 inch dob and the difference on DSO,s is quite noticeable, more contrast in larger aperature.
As has been stated the comfort factor is a huge plus, you seam to spend more time looking at one object, than when in mono.
I now use the bino most of the time, mainly due to the poor seeing conditions.
What ever you decide enjoy
Cec

[astropolak (Joe)]

Originally Posted by Satchmo

I once compared the view through a 13" Newtonian fitted with $2000 Televue binoviewer against a farly crude 6" F8 Binocular Newtonian and decided the 6" binos won clearly on contrast and sharpness. Whilst Binoviewers are a really compact choice , I think as time goes on , the merits of even low cost 6" and 8" true binocular scopes built for under a $1000 will surface.

It does indeed look that the only way forward (at least for me) would be a nice Bino telescope, a 12-14" perhaps....some time in the future.
At least I have the eyepieces to start the project with...

Joe

[janoskiss (Steve H)]

I've owned Burgess BV125 and Siebert BN 22 (briefly before returning it). The Burgess was the better unit in every way. There was noticeable degradation in sharpness and contrast at high powers compared with single EP view alone but still a fantastic experience to be able to use both eyes. Mainly useful on Saturn & Jupiter at mid-high powers - did not find it so useful on DSOs mainly due to narrow tfov with the corrector/barlow needed to reach focus in my Dobs. There were some reflections / stray light when viewing bright targets like planets, which were somewhat annoying.

[Neil]

thanks to everyone for your interesting and usefull advice

[OneOfOne (Trevor)]

I bought a WO bino viewer with my new C11 and even with the collimation problems I am having (but that's another thread) I swung it around last night to the Moon and was rather impressed with the effect it gave. I look forward to revisiting it when I have solved my current problems.