Help Understanding Magnification (1 Viewer)

Post 20.

Unusual ruler with width measurement also marked.

I have always wondered about high street ruler's accuracy. I don't think that they are accurate.

B.

Binastro said:

Post 20.

Unusual ruler with width measurement also marked.

I have always wondered about high street ruler's accuracy. I don't think that they are accurate.

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It's from the stone ages, more or less. :gh: I've had it for as long as I can remember.


Probably not super accurate, but definitely the error on the ruler is negligible compared to other errors in this context. But it will definitely tell you if you have a 2x bino, or a 7x.

Off topic slightly but picking up from posts 20-22, I bought a steel rule from a major DIY store once and it actually had a disclaimer on it that it may not be accurate - hardly a good advert!

Try looking at a brick wall at some distance away. Use just one side of the binocular and superimpose the binocular view over that of the naked eye view. Count the bricks, I have always found the number to be consistent with the magnification, after allowing for the cement in between.

Ditto, brentwood.

Regards,
B.

hap said:

Now I am wondering if I should go 10x rather than 8x for new binoculars. I know I would be adding stabilization risk with more power but it seems I am going to perceive half or less of stated power so would like a little more reach for the sort of all purpose birding, stars, airplanes viewing I regularly do. I was looking at 8x32 sort of stuff but not sure now.

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I use 10x32 regularly myself and you might indeed prefer it just as I do. But it sounds like the bigger issue for you might be field of view, which can affect your perception of magnification and the overall experience of immersion. Real FOV varies among models of the same magnification, and apparent FOV is also influenced by eyepiece design -- flatter-field models popular today typically have less. Try out a Leica UV 10 or 8x32, with more traditional design and a wide AFOV, to see what I mean, then see what's available at your desired price point. (The older Trinovid models would be comparable, but I have no experience with their current ones.)

hap said:

This is probably going to sound stupid, but is magnification linear or logarithmic? I ask because whilst looking through some 7x binoculars I was thinking how objects don't appear 7x larger in my perception. I looked at a barn as a target, raised them up and looked at it with the naked eye, and back and forth to compare. To my perception the barn only appears 2x larger in the binoculars as opposed to unaided. Certainly not 7x larger. Am I missing something fundamental?

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Hi, Hap:

You have had a number of pertinent answers but, as the answers are spilling over to a second page, I think a simplification is in order:

— The numerals on the backplate of a binocular manufactured by an honest manufacturer indicate the apparent increase in image size ... period. That has nothing to do with PERCEPTION and everything to do with physics—6-year old or 60, Einstein or idiot it’s all the same.

— If that is not YOUR perception, you should talk to an optometrist or ophthalmologist about the issue. BF has many bright folks among its members—the best I’ve seen. However, you might specify you would like opinions only from those QUALIFIED respondents. Your issue gets into things most of us are not clinically (physiologically) prepared to discuss. Opinions won’t drive nails; you need facts.

Finally, I would ask that for the edification of all you let us know what you ultimately learn about the issue. :cat:

Bill