But it‘s much easier to fix if it ain‘t broke 🤔
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Binoculars convention should be Aperture Divide Magnification, not Magnification x Aperture... ? (1 Viewer)
- Thread starter kimmik
- Start date
kimmik
Well-known member
Summarising:
10x50 binocular
(Ten By Fifty binocular)
IMHO should actually be labelled
Fifty By Ten binocular, written as
50/10
50mm aperture
10x magnification
Because mathematically:
10x50 = nonsense
50/10 = exit pupil
Furthermore, with Keplerian telescopes:
Aperture is king, and deserves to be the first number.
10x50 binocular
(Ten By Fifty binocular)
IMHO should actually be labelled
Fifty By Ten binocular, written as
50/10
50mm aperture
10x magnification
Because mathematically:
10x50 = nonsense
50/10 = exit pupil
Furthermore, with Keplerian telescopes:
Aperture is king, and deserves to be the first number.
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Uh, cuz you wanted to buy 32 square feet of plywood, right?
In reverse order,
Yeabut, these 10x50s are binos....
And
Mathematically 10x50 = 500. indeed as a descriptor of a bino that is nonsense. But why does the presence of a number.. in a phrase/label/sentence, require a math function be applied? Our Quant Prof in B-School, on day 1 knowing many in the class were math avoidant pitched the idea, that algebraic expressions might be thought of as alternative languages, (sure Im not doing him justice). One can learn the vocabulary and rules of a new language, (which probably contain their own words for numbers and math functions). And/or similarly, one can look at an algebraic expression, understand the functional symbols, PEMDAS, the variables read and comprehend it like a sentence with practice. Surely.
But Kimmik, why do you argue the presence of a number in a descriptor means a mathematic function, interpretation is required?
I get the winter migration is over, Ive spent my bino budget for this year and things are slow, but....
Paultricounty
Well-known member
Did you mean 2.97 square maters 🙃
Paultricounty
Well-known member
We’re leaving out that most binoculars labeled 8x, 10x etc. etc. are not exact and can be off more than 10%, which then changes the math on the exit pupal. Except maybe the objective size number 🤔
Pinewood
New York correspondent
Hello Kimmik,
For years there was an article in Royal Astronomic Society of Canada's annual handbook about using binoculars. He advocated using just such a function for comparing binoculars. If one thinks a little, this is just a variation of the twilight factor.
Stay safe,
Arthur
tenex
reality-based
Theodore Maiman? (I admit I had to google it)
Indeed, you could quote another more famous man: "The book of nature is written in the language of mathematics."
The common 5x30, 4x30 coated binoculars are in fact Galilean glasses.
So 30x5 or 30x4 gives the exit pupil.
Actually, no, as there is no external exit pupil.
With early binoculars and field glasses just the magnification was given.
With telescopes, just the aperture, such as 2 1/2 inches.
With earlier telescopes just the length, i.e. the 7ft telescope.
This was the focal length with no aperture and no magnification.
As to the exit pupil, this depends on prism size and internal vignetting.
As mentioned the very nice Optolyth 12x50 is actually 12x42 with an odd shape exit pupil.
The Kite IS binoculars have a chunk eaten out of the objectives.
As mentioned it should say 10x, 50.
I have seen several binoculars so marked.
I have a Handbook that has been going for perhaps one hundred years. I have had them for sixty years.
The new editor decide to be Logical and rearrange the whole Handbook according to strict logic.
In my opinion the present Handbooks are a complete mess, because the necessary information was previously sensible, and now I can find nothing unless I look up the page of contents or try to think how logic is supposed to work.
There are many cases of new editors messing up entirely sensible texts just to put their mark on the publication.
It is another case of new, new, new.
New must be better.
Well it isn't.
B.
So 30x5 or 30x4 gives the exit pupil.
Actually, no, as there is no external exit pupil.
With early binoculars and field glasses just the magnification was given.
With telescopes, just the aperture, such as 2 1/2 inches.
With earlier telescopes just the length, i.e. the 7ft telescope.
This was the focal length with no aperture and no magnification.
As to the exit pupil, this depends on prism size and internal vignetting.
As mentioned the very nice Optolyth 12x50 is actually 12x42 with an odd shape exit pupil.
The Kite IS binoculars have a chunk eaten out of the objectives.
As mentioned it should say 10x, 50.
I have seen several binoculars so marked.
I have a Handbook that has been going for perhaps one hundred years. I have had them for sixty years.
The new editor decide to be Logical and rearrange the whole Handbook according to strict logic.
In my opinion the present Handbooks are a complete mess, because the necessary information was previously sensible, and now I can find nothing unless I look up the page of contents or try to think how logic is supposed to work.
There are many cases of new editors messing up entirely sensible texts just to put their mark on the publication.
It is another case of new, new, new.
New must be better.
Well it isn't.
B.
That's true, Peter.
As to logic and common sense.
I suppose pilots with head up displays have to adapt to either logic or common sense depending on what is being shown.
With the Airbus that landed in the Hudson, the most important information was way down the check list and would not have been dealt with.
The pilot quickly said, switch on or drop the windmill that gave emergency power to essential instruments.
The pilot luckily was a very experienced glider pilot and knew the correct landing angle, maybe 11 degrees.
The logical checklist was compiled presumably by logic. It was deficient because it lacked common sense.
Regards,
B.
As to logic and common sense.
I suppose pilots with head up displays have to adapt to either logic or common sense depending on what is being shown.
With the Airbus that landed in the Hudson, the most important information was way down the check list and would not have been dealt with.
The pilot quickly said, switch on or drop the windmill that gave emergency power to essential instruments.
The pilot luckily was a very experienced glider pilot and knew the correct landing angle, maybe 11 degrees.
The logical checklist was compiled presumably by logic. It was deficient because it lacked common sense.
Regards,
B.
Quite so, but what we are discussing isn’t a mathematical expression.
The quote has been copied so many times, I doubt anyone knows who said it first.
Binocollector
Well-known member
Galilei, I thought.
kimmik
Well-known member
Better than 10x50 I agree.
50mm, 10x would be even better IMO.
I would not pay the same price for 10x25 vs 10x80, so i prefer to think of them as 80/10 and 25/10.
Marketers will happily advertise 1000x50 telescopes (as you've noted many times before), but perhaps they wont succeed with 50/1000, for the good of humanity.
Sure, but at what point do we morph into an Amish/Luddite.
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kimmik
Well-known member
Agree, though that problem isn't solvable by 10x50 either.
So 12x25mm=300, and 7x42mm=294, are comparable?
What about 50x20mm=1000, same as 12x80mm=960?
Marketers will be happy to know you support their claim that their dollar binos can compare with 12x80mm units.
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Tho, err… more like - should it be? Still hoping for a point
kimmik
Well-known member
You won $1million.
Except that isn't a dollar sign, it is S and I overlapped which just looks like a dollar sign by coincidence.
If 10x50 isn’t meant to be mathematical, perhaps they should stop using this ambiguous label.
My point is, it is rather convenient for the marketers, that 10x50mm convention is written like maths, so that some subconscious part of you thinks 100x50 is better than 10x50.
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