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Need advice on mechanical quality of zoom binos

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#76 BillC

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Posted 24 January 2013 - 11:17 AM

This is what we're trying to determine, Rich.


Understood. However, just as it easier to make a 6-inch mirror AND a 12.5-inch mirror than a 12.5-inch mirror alone, it will be easier for CuriousOne to make better decisions and ask more pointed questions by taking some time off to read a little on optical realities. Stuffy or not, without doing so, this thread will grow to be 10 pages in 4 more days and CuriousOne will know little more than he does now. But, I have approached that logic several times to no avail, so I will stop recommending it. :bawling:

Cheers, :jump:

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#77 Rich V.

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Posted 24 January 2013 - 11:54 AM

It just seems to me that an inexpensive 30x80 bino will provide all the reasonable magnification that can be had for terrestrial use. More magnification at long distances more often than not just doesn't cut it due to surface atmospheric disturbance which has already been discussed here. A 30x80 provides a usable ~2.5mm exit pupil with a usable focusing mechanism and IPD adjustment incorporated into a handy package. Hard to beat, IMO.

For me, even my higher quality 22x binos show too much air turbulence at long distances under many circumstances.

This query seems to be headed to a lot of trouble for little realized good.

Just my opinion, of course...

Rich

#78 Mark9473

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Posted 24 January 2013 - 12:17 PM

How does one propose getting a proper interpupillary distance with two 100+mm diameter optics if these Maks are used? Do they have enough back focus for prism assys to be incorporated? Did I miss something here?

The idea was to mount a porro binocular body with the objective barrels removed, behind the two lenses. He tried with one binocular but that wasn't wide enough. He had another one that was wide enough, but that was defective on one side.

#79 CuriousOne

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Posted 26 January 2013 - 05:22 AM

Say the 3 fold calendar, like this:

https://sites.google...INGCALENDAR.jpg

is hang about 180 meters away and binoculars allow to distinguish and read smallest text ("week") on them. Such binoculars are considered good or bad?

#80 EdZ

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Posted 26 January 2013 - 10:01 AM

Say the 3 fold calendar, like this:

https://sites.google...INGCALENDAR.jpg

is hang about 180 meters away and binoculars allow to distinguish and read smallest text ("week") on them. Such binoculars are considered good or bad?


without knowing the actual size of the letters and the power at which the binocular is used, this question, which really measures only one aspect, resolution, cannot be answered. Even if yyoou knew alll the above and were abble to ansswer the question, theres's at leastt anotheer 10 aspets of performaancce to measure to determine if ythe binocular is good or bad.

#81 planetmalc

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Posted 26 January 2013 - 12:21 PM

Instruments like this HAVE been produced commercially: I went to the London Astronomy Show a few years ago and one of the Russian companies - Intes, maybe - had produced a pair of 6" Maksutovs with Porro 1 prism/eyepiece units for in-line viewing. They gave a very sharp image.

#82 CuriousOne

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Posted 26 January 2013 - 12:42 PM

Actual size is about 20mm x 6mm.

Power unknown, since this is homemade binocular.

#83 EdZ

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Posted 26 January 2013 - 02:35 PM

Actual size is about 20mm x 6mm.

Power unknown, since this is homemade binocular.


Which letter the W?

that would be appropriate for testing a 10x to 12x binocular at that distance. Any higher magnification than that and those letters would not be small enough to test the resolution of the poweer being used.

edz

#84 Simon S

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Posted 26 January 2013 - 03:55 PM

You will find none of the High end binocular manufacturers selling zoom binoculars, although Nikon ans a few others do sell a zoom to cater for public demand.

#85 SMark

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Posted 26 January 2013 - 07:41 PM

You will find none of the High end binocular manufacturers selling zoom binoculars, although Nikon ans a few others do sell a zoom to cater for public demand.


Has anyone here actually tried either of the Nikon Action Zooms?

#86 GlennLeDrew

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Posted 26 January 2013 - 08:25 PM

Fellas,
It's been established already that the word 'zoom' in the title actually should have been 'high magnification'. What we know of as a zoom bino is not what is being sought.

#87 stormbird

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Posted 02 February 2013 - 03:21 AM

I have the Nikon 8-16x40 XL binoculars. Sharp as any binos I have ever owned (30+). They are much smaller than your requirement, but very handy. At 8x the fov is fairly tight, but better at 12-16x. My 2 cents.


Probably off topic from original poster of large zooms but.....

I always heard that the one zoom exception is the 8-16x40 XL Nikon zoom. So when I checked one out, I personally found that it was certainly usable and sometimes convenient.

But it's costly and nowhere to be found....

Jae



#88 CuriousOne

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Posted 02 February 2013 - 05:49 AM

Specs are fine, but instead 8-16x40 I'd prefer 16-32x80 :)

#89 Rich V.

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Posted 02 February 2013 - 02:18 PM

The above now discontinued Nikon zoom is the only zoom binocular that I've ever heard positive reports about.

I'm sure BillC has had some of those pass through his hands over the years; he could tell us if there's anything to it or whether it's just the luck of the draw for those owners. I'd trust Nikon to do a better job of it than some of the other suppliers we've been discussing...

Rich

#90 Sean Puett

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Posted 04 February 2013 - 08:41 AM

I had some of the Zhumell zoom 10-30x50 binoculars. They were pretty good for daytime use if you are not overly critical. They were only $50 new so you need to factor that in. Night time use was another matter. They weren't perfectly collimated so that was part of the issue. Then when you zoom, it made collimation errors worse.

#91 CuriousOne

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Posted 09 February 2013 - 03:11 PM

Tomorrow, I'll post a series of photos, which shows what I was questioning about, and what I got as answer :)

#92 SMark

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Posted 01 March 2013 - 10:15 PM

You will find none of the High end binocular manufacturers selling zoom binoculars, although Nikon ans a few others do sell a zoom to cater for public demand.



This one REALLY caught me by surprise...

A Fujinon Zoom... Really?

#93 hallelujah

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Posted 02 March 2013 - 12:31 AM

http://www.ebay.com/...PRISM-SYSTEM...






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