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Magnification of monoculars vs. binocular. Question

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#1 Loukanikos

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Posted 11 January 2017 - 03:25 PM

Hello to all!!

 I have a question regarding monocular & binocular magnification.

Assume that we have two monoculars with magnification 0.97 & 1.03 , respectively. If we combine them to have a binocular, what would be the magnification of the instrument & why? Is there a formula for such a calculation?

 

Thanks in advance for all replies

 

 



#2 Astrojensen

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Posted 11 January 2017 - 04:02 PM

???? One side will have a magnification of 0.97x and the other side one of 1.03x. This is a 5% difference, which is borderline on being intolerable. 

 

But if your question is how much larger objects will appear in a binocular, than with a monocular of the same magnification, then this varies from person to person, but I personally seem to see details as easily with binoculars, as I do with a monocular with ~25% higher magnification. The contrast increase is some 41%, because the brain has twice the signal to work with.

 

 

Clear skies!
Thomas, Denmark


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#3 GlennLeDrew

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Posted 11 January 2017 - 06:04 PM

I too am confused by the question. Some clarification?

 

In the meantime, I will say that if the instruments differ by more than a few percent in their image scale image fusion is compromised, and the brain will not derive the full benefit of the image pair. The magnification difference for any tolerably disparate system will/should be so small as to render moot the need to consider this aspect. Suffice it to say, for an observer not having particular dominance of vision for one eye, the perceived magnification will be the mean, or average value. But if one eye is notably dominant, the perceived magnification might (?) be nearer to that of the instrument it is peering through. 



#4 Loukanikos

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Posted 12 January 2017 - 01:47 AM

Hi! Thank you for your replies.

 

So, if I get it right, the magnification of the bino will be the average value (considering no dominance of one eye)? this is kind of subjective measurement (depending on the person testing the instrument).

 

During monocular construction, there are a few dedicated softwares that calculate the magnification. Assuming that we would like to construct an 1X magnification instrument (e.g. night vision bino). First, we assemble two monos, measure the magnification and then join them with a bridge to have a bino ( of course, collimation etc. not mentioned here). Thus, if the measured magnifications are the aforementioned, what would be the measured magnification of the bino (by using a beam combiner and only one camera)? if this helps, consider the process for resolution. First, we measure (with the eye) the resolution of each mono and then with a beam combiner we see and measure the resolution of the bino, as a whole.

 

Hope this clarifies somehow my question!



#5 GlennLeDrew

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Posted 12 January 2017 - 11:56 AM

For a system employing sensors such as NV tubes, the optics need be just objective lenses of the same focal length on the object side, and same f.l. eyepieces attached at the back. It would be inefficient to make up complete, stand-alone monoculars to use in the afocal mode, unless the device to be attached to already has a built-in, non-removeable objective.

 

If the device has non-removeable objectives, the afocal attachment should at least send light into most of the entrance pupil, and over at least most of the field of view, so that image brightness be not too much reduced and that vignetting be not egregiously apparent.




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