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Ultra Light Binoculars For Astronomy

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#26 Grimnir

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Posted 10 June 2020 - 01:24 AM

Compared Zeiss 10x25Bto Japanese 10x70s. Looked at Moon and Lyra area.

Zeiss was much sharper. Moon edge was crisp and stars were pinpoints. Even bright stars and the faint ones were extremely small.

 

Now the 10x70 was brighter of course but did not overwhelm the smaller instrument. Stars were blobs and more irregularly shaped. So the light was not as well focused to a tiny point but spread over like a crude dob.

Which Japanese 10x70?

 

Graham



#27 publin

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Posted 11 June 2020 - 11:56 AM

 product.  high   end   compact  size   bino's   as  this  above  mention   is mainly   good    for   terrestrial    view    or   birding   or   best for spy....    not   for  astronomy.    [    galaxies / messiers/ our   solar  planets]  due  to  there   small  exit  pupil  and  small  objective  lens   and   .despite  the  top   quality  lenses        that   enable   to   view   also  in   nighty   sky     but    for  real   star gazeing     viewing    only  a   big  astronomic bino can   better     use   for   that.       as  you   will   not   take  to  theater    astrobino....!   or   watching   birds   with   theater   bino.....!     each   view   target  has  the  proper  instrument.  



#28 saemark30

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Posted 13 June 2020 - 01:59 AM

When I say Japanese 10x70 binoculars I have some generic Japanese ones with single coatings and BK7 and 3 element Kellners. I wonder if the Celestron Skymaster 15x70 is any good. Remember those objectives are working at F4 so there are boatloads of aberrations from that alone. I am sure Nikon and Fujinons are much better but they just might be outsourcing from Japan to CN these days.

With the Zeiss all stars look like points. And the milky way is fine dust rather than hail looking stones.



#29 Jon Isaacs

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Posted 13 June 2020 - 06:19 AM

Compared Zeiss 10x25Bto Japanese 10x70s. Looked at Moon and Lyra area.

Zeiss was much sharper. Moon edge was crisp and stars were pinpoints. Even bright stars and the faint ones were extremely small.

 

Now the 10x70 was brighter of course but did not overwhelm the smaller instrument. Stars were blobs and more irregularly shaped. So the light was not as well focused to a tiny point but spread over like a crude dob.

 

Big difference in weight. Which one would you prefer hanging around your neck?

This time, I will take the much smaller and more precise instrument the Zeiss 10x25B.

 

I think what you are seeing is the difference between a 2.5mm exit pupil and a 7mm exit pupil.  Your eye is operating at about F/7 with a 2.5 mm exit pupil, about F/2.4 with a 7mm exit pupil.  With a 2.5 mm exit pupil, you are only using the central part of the lens, the 7mm exit pupil you are using the entire lens, the center is the better part.  

 

You can do this experiment.  Use a high quality optic begin with a large exit pupil 5mm or so.  Look at a moderately wide double, I used 7" in an 80mm apo at 17x.  Using aperture masks, observer the sharpness of the image as the exit pupil is decreased at a constant magnification.  I found that 2.5 mm was about the optimal.  

 

The human eye is only diffraction limited at exit pupils under about 1 mm.  

 

Jon


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#30 saemark30

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Posted 16 June 2020 - 02:47 PM

Jon you make a good point. However I was observing with street lights in my face during the comparison so my pupils were no larger than 4mm I would say.

And using Bushnell 8x21 binoculars is pure torture. The images are mush, dim, not sharp and low contrast.

Using aperture masks with quality optics will make the objective sharper and eyepiece handle the light cone easier.Kellners are not good at F4 which is what all binoculars operate. You would no more use than in your fast dob.



#31 mario777

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Posted 21 June 2020 - 10:01 PM

try Bushnell 4x32, they are ultra lightweight. 



#32 ov1vas

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Posted 14 July 2021 - 07:30 PM

Hello everybody.
I want to consult the community about a new purchase that I want to make of 2 vintage binoculars
I am looking at an auction to buy one of these 2 binoculars:

Bushnell Custom Compact 7x26 (7 *) Bak4
Made in Japan 1976
or
KOMZ БШЦ2 6x24 (11.5 *) Bak4
Made in Russia 1975

 

Assuming the 2 binoculars are in perfect condition and each costs $ 10.

Which of the 2 models would you choose to have it in the car to carry out "with daylight", quick observations from the distance of highway signs and see wide landscapes from the car.

 

I am looking for a binocular that is small and when I put it in front of my eyes, it has a fast focus and a very pleasant view.

I appreciate your recommendations



#33 SMark

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Posted 14 July 2021 - 07:48 PM

I would buy both, as each is worth way more than $10. I don’t really like small binoculars much, but I have had both of these and each was well made and performed well enough.
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#34 ov1vas

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Posted 14 July 2021 - 08:46 PM

Hello, thank you very much for the quick response

Did you get to have both binoculars?

Which of them would you stay with if you had to leave one of them?



#35 ov1vas

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Posted 14 July 2021 - 09:01 PM

This is a link of the KOMZ БШЦ2 6x24 (11.5 *)
This komz has very bright and clear views
https://www.youtube....h?v=DhpOHgWFahg



#36 SMark

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Posted 14 July 2021 - 09:40 PM

Yes. I would go with the Komz.


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#37 Grimnir

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Posted 15 July 2021 - 03:02 AM

Hello everybody.
I want to consult the community about a new purchase that I want to make of 2 vintage binoculars
I am looking at an auction to buy one of these 2 binoculars:

Bushnell Custom Compact 7x26 (7 *) Bak4
Made in Japan 1976
or
KOMZ БШЦ2 6x24 (11.5 *) Bak4
Made in Russia 1975

 

Assuming the 2 binoculars are in perfect condition and each costs $ 10.

Which of the 2 models would you choose to have it in the car to carry out "with daylight", quick observations from the distance of highway signs and see wide landscapes from the car.

 

I am looking for a binocular that is small and when I put it in front of my eyes, it has a fast focus and a very pleasant view.

I appreciate your recommendations

 

Both are good binoculars - you'd be crazy not to buy both at that price.

 

Graham



#38 ihf

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Posted 15 July 2021 - 05:38 AM

I have not tried either. But the komz is pretty unique and hard to find here. Might be different where you are.

#39 ov1vas

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Posted 15 July 2021 - 09:48 PM

Thank you very much for your recommendations.
First I am going to review to buy the KOMZ БШЦ2 6x24 because it is more difficult to get and more exotic
And then, I'm going to review to buy the Bushnell Custom Compact 7x26

 

If both are in good condition, I will buy both.


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#40 ECP M42

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Posted 15 July 2021 - 11:57 PM

Anyone else using small 8x20 and 10x25 high end binoculars?

 

 

Let me know what Messier objects you have seen in them.

It would be interesting if one can see/detect many galaxies.

A few months ago I saw Andromeda with the naked eye. I had with me a vintage 8x30 and a modern 10x32 FMC, BaK-4, PC and all the other things they must have.

Between the two I preferred the observation with 10x, but both were in my eyes "very bright" or low in contrast. And since I had the Trinovid 10x25 BCA, I thought it would be great on that occasion, to darken the sky a little more and give me a better apparent contrast. 

 

In any case, I believe 10x is a low magnification for galaxies, clusters, and planets and I think for many Messiers as well.
The Moon is fantastic with the Trinovid and at that magnification it was my best observation: neutral colors, natural contrast, excellent transparency and high resolution of the details. Flawless sharpness, no ghosting and just a slight side CA formation near the edge of the pitch, which wasn't involved. 


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