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Big Binoculars for Birding - a Pipe Dream? (1 Viewer)

I used a selected Soviet 20x60 binocular hand held for more than ten years without a problem.
I did brace it on whatever was nearby.

It was specially made as one of about a dozen for Jim Hysom.
I think George Alcock used one to discover a comet or nova through his landing window.

The later Russian ones post 1990 are usually pretty useless. Made from parts with no serial numbers in many cases.

There is a Russian 26x70, which maybe O.K. But I never owned one.
Probably the rear end of the 20x60 with longer 70mm objective barrels.
 
Hi John,

Tringa45 said:
Wouldn't it be nice to have something like a 25x75 or 30x75 binocular with central focussing? BUT at the same distance a 25x binocular has about one tenth the depth of field of an 8x binocular. The mechanical precision required to attain synchronous movement of the oculars or IF elements would be so high as to place the binocular beyond the financial reach of most potential customers.
Click to expand...

Thinking about it, I wonder if there's a way to circumvent the problem of a non-synchronous drive train by making the drivetrains independent, electronically actuated, and position-sensing. Then, it would only be required to calibrate the position-sensing mechanism - ideally only once after final assembly, but it might be possible to provide a self-calibrating mechanism as well.

That's certainly a non-traditional solution that deviates from the batteries-not-required, milled-from-a-solid block approach that makes high-quality optics so appealing to everyone, and it probably would drive the price up as well since the development cost would have to be paid for by what I'd expect to be fairly few sold examples.

Regards,

Henning
 
Hi,

I haven't tried it, but Teleskop Express has a pair of 20x80 central focus bins... straight through and fmc with a field of 56/1000m or 3.2 deg and 17mm eye relief but rubber fold-down eyecups - not sure how they manage for 145€ although at that price I'm inclined to try it...

EDIT: I have ordered one... couldn't resist - usually TS doesn't sell junk.

https://www.teleskop-express.de/sho...lars---LE-Series---Light-Gathering-Giant.html

Joachim
 
When I considered large bins some time ago, I found the reason not to bother is their unsuitably long close focus. Measured in tens of metres.
A deal killer for me.
 
Boogieshrew said:
When I considered large bins some time ago, I found the reason not to bother is their unsuitably long close focus. Measured in tens of metres.
A deal killer for me.
Click to expand...

Hi,

that is correct - the TS one has 30m or so. If that bothers me, I'll build a parallelogram mount and use it for stargazing in a deck chair...

Quite frankly for birding I like a 45 deg spotting scope because it is 45 deg and has only one eyepiece and thus can be used by a group when something nice is visible.

If you have a pair of straight through big bins you need to adjust the height and the interpupilary distance and that means the bird will not be in the field of view any more for multiple reasons...

Joachim
 
Many years ago I was at Park cameras Burgess Hill? and they had 3 Japanese centre focus 30x80 binoculars.
They had a long viewing distance outside the shop and I bought the best of the three after careful testing.
But I could never really use it as the eye relief was almost nil. I could just see the whole approx. 2 degrees field if I pushed the eyecups against my face.
In addition hand holding was almost impossible unless very firmly braced.
It was only about £50.

Also very long minimum focus.

However, the Japanese Celestron 20x80 and Soviet 20x60 were used for years.
I also have a good Japanese 20x70.

My Celestron 25x70 has very poor optics although some report that they are O.K.
 
Hauksen said:
Hi John,



Thinking about it, I wonder if there's a way to circumvent the problem of a non-synchronous drive train by making the drivetrains independent, electronically actuated, and position-sensing. Then, it would only be required to calibrate the position-sensing mechanism - ideally only once after final assembly, but it might be possible to provide a self-calibrating mechanism as well.

That's certainly a non-traditional solution that deviates from the batteries-not-required, milled-from-a-solid block approach that makes high-quality optics so appealing to everyone, and it probably would drive the price up as well since the development cost would have to be paid for by what I'd expect to be fairly few sold examples.

Regards,

Henning
Click to expand...

Would it not be simpler to put a binoviewer on a single objective?
At the distances where high power binoculars excel, there is no parallax to speak of anyway and the mechanical issues would be avoided.
 
Hi Etudiant,

etudiant said:
Would it not be simpler to put a binoviewer on a single objective?
At the distances where high power binoculars excel, there is no parallax to speak of anyway and the mechanical issues would be avoided.
Click to expand...

The disadvantage of bincoular eyepieces on a single objective is that each eye only gets half the light, so the image is not as bright.

It might well be that this can be compensated for by using a larger single objective while staying in the same weight/bulk class as the bincoulars, but eliminate the technological complexity just as you suggest.

On the other hand, having played around with stereoscopic photography and image viewing a bit, my non-scientific impression is that the eye can actually get a stereoscopic view at longer ranges that usually claimed ...

Regards,

Henning
 
etudiant said:
Would it not be simpler to put a binoviewer on a single objective?
At the distances where high power binoculars excel, there is no parallax to speak of anyway and the mechanical issues would be avoided.
Click to expand...

Hi,

that is a valid statement, but having two objectives means you have more area and thus more light (which of course could be reached with one larger objective too) and more crucially, you have two different optical paths, which helps to counteract seeing effects.

Plus of course, getting a high quality binoviewer is also not cheap...

Joachim
 
etudiant said:
Would it not be simpler to put a binoviewer on a single objective?
At the distances where high power binoculars excel, there is no parallax to speak of anyway and the mechanical issues would be avoided.
Click to expand...

I spent some time with the Swarovski BTX and just couldnt get the IPD system to work for me unlike standard binoculars which was a real shame unlike a pair of Kowa Highlander which was outstanding.
Both "alpha" optics but what a difference to me, the user.
P
 
Hauksen said:
On the other hand, having played around with stereoscopic photography and image viewing a bit, my non-scientific impression is that the eye can actually get a stereoscopic view at longer ranges that usually claimed ...
Click to expand...

Hi,

I would agree if you call it threedimensional instead of stereoscopic.

Stereopsis really needs two sensors/eyes which are some non-trivial distance as compared to the object distance apart and the larger that distance is, the stronger the 3d effect due to stereopsis is - and thus you can see threedimensionally due to stereopsis at farther distance than normal. See Scherenfernrohr or scissors telescope which does just that.

But there are also ways to see threedimensionally with only one sensor/eye and those are obviously will work up to infinity.

There are astro eyepieces which use some funny distortion tricks to generate a 3d effect at infinity - but that is quite artificial - the perceived depth information depends on where in the field of view a star is situated.

Joachim
 
Hi Joachim,

jring said:
I would agree if you call it threedimensional instead of stereoscopic.
Click to expand...

Hm, I now see that my previous post was arranged rather poorly ...

What I meant to say is that I don't necessarily agree that at normal birding distances, there's no stereoscopically useful difference between the pictures from a two-objective binocular telescope.

I didn't mean to address the various secondary ways the human brain uses to derive both true and illusionary depth information, though that would quite an interesting topic in itself! :)

Regards,

Henning
 
In the spotting scope section, there is a discussion of most useful magnification. Many people responded between 20-30x. Which is consistent with other threads similar to that one.

It got me thinking if that’s the case I might as well use a high power binocular for more comfortable two eyed views without the fatigue you get from spotting scopes. Plus you typically get a wider field of view

With binoculars like the Nikon monarch 5 20x56. They are small and lightweight (realitively speaking). It almost seems like a no brainer. Yeah it requires a tripod, but So does a spotting scope
 
Putting aside the weight of 25x75 or 30x75 binoculars as you describe in your first post, and the tripod they'd require, and at the distances these would be best suited for, individual focus isn't so bad. With use one gets pretty fast at focusing IF bins. After all it's not like you'll be tracking warblers from 30' flittering in the reeds.

Here's a method I use that works great for me though at least one other here on BF found it unacceptable:
Focus one EP to a middle distance somewhere and the other EP closer to infinity. You might be surprised at the depth of field and your ability to spot lots of things. Once found, simply fine tune focus and your subject is likely to stay within the depth of field. This takes but a couple of seconds longer than a center focus bin. Also many IF bins have index numbers on the EPs that, once familiar with allows one to focus one EP then simply turn the other EP to the corresponding index number. This can help novices with IF bins.

To sum up, I don't think that IF is the limiting feature of such big bins. Size and weight are significantly more of a hindrance.
 
Thanks! I wish he'd post about eight times as often, so I'll (try to) follow some of what gets said on that forum with real interest.
 
Big binoculars are not a pipe dream, not sure why that was presented that way. There are many
choices in the realm of quality binoculars in the larger sizes of 15X and higher.

First off I will mention my experience, the cheap astro 15x70 binoculars are just that, cheap,
and often are out of collimation. The Celestron 15x70 Skymaster, should come with instructions
on how to tweak the prism adjusting screws. Those instructions, may be included with purchase.....

Good ones that I have or have had are the Nikon 15x56 and 20x56 Monarch 5 models, they both
deliver a nice view, and tripod mounted of course, for the best use.
The Swarovski 15x56 SLC Neu, Zeiss Conquest HD 15x56, and the Docter Nobilem 15x60 are also great choices.
Your budget will help you in deciding which one is for you. There are many reviews out there, so
no need to explain that here.

Comparing with a spotting scope is natural, and looking with 2 eyes rather than one is a great
advantage for comfort, and ease of view.

Holger Merlitz does post on here, every once in a while. PM him, if you wish and encourage him to post more.
He has his own site, that I look at regularly, he keeps it up, with new reviews, and he has a book that
he wrote a short time ago. When it is printed in English, I will buy one.

Jerry
 
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