Learn me on optics

huge, very broad subject.
in a nutshell, the more you pay, the better scope you'll get.

longer version:

repeatability - when you spin the turrets up for a distant shot, and then come back down, does the group print in the same spot?

tracking - just cuz the scope says it moves .25 moa per click doesn't mean it does. more expensive scopes will be closer to .25 per click. cheap scopes may be .25 this click, but next will be 1 moa, and the next 2 may not move it at all.

clarity - can you see thru the scope?

resolution - how fine of a detail can you see w/ the scope?

brightness - can you only see the target at high noon on a snow-covered open range w/ a cloudless sky?

main tube - can vary a ton. most common is 1" and 30mm. theory is that 30mm can transmit more light to the eyepiece so they are brighter. however, less expensive scopes just have the 30mm tube w/ 1" internals - so you gain the elevation and windage advantage of the bigger tubes, but you do not gain light transmission.

durability - can the scope tolerate a whack, and hold zero, not curl up the reticle, and retain all its other features? you'd be shocked how many scopes can't take even a mild thump w/o either radically adjusting their zero for ya, or breaking alltogether.

objective - usually measured in mm, and is how big the bell is.
eyepiece - what you stick close to your eye, and if it is a variable scope, then it is what you adjust the power setting w/.
-- the human eye in good shape can handle about 7mm of light. so, a scope w/ a massive objective and small variable power is mostly a waste. a scope that is a fixed 10-power and has a 50mm objective can transmit, under optimal conditions, 5mm of light. a scope that is a fixed 6-power scope w/ a 50mm objective transmits about 8.5mm of light - more than your eye can use. so, what's wrong w/ more? nothing - except 50mm and bigger objectives look funny on certain guns, they are more expensive, and heavier...

weight - a heavy scope doesn't tolerate recoil as well as a lighter scope.

there are many more hours we can go on this subject - so, i'll quit for now, and let someone else add their own ideas in, and maybe you'll generate some specific questions so this doesn't turn into a novel!

Try doing a simple query using a search engine.

Optics for the Hunter, by John Barsness, available at http://www.riflesandrecipes.com

Check out this forum or this forum. Another good place to just shop around and see what's what is here.

[thread hijack]

For an M1A, you're going to have more of a hassle getting the mount than the scope. Get the ARMS #18 first. Don't buy the Springfield if you value your eternal soul .

Shoot it a few times.

Then, pull the mount and scope off, and put the mount in a drawer, and put the scope on a nice bolt action or something, because you'll find the sights on an M1A are as close to perfect as anything on the planet this side of Jessica Biel.

[/thread hijack]

S/F

Farnham

Well, dakotasin just gave you (and the rest of us) an outstanding summary - thanks. I'd just mention that you have different wants/needs for different tasks - with target shooting, you want high magnification optics. For hunting, a much lower magnification, as a general rule, particularly hunting large game.

OT because it's concerned with binoculars, but this article on my site is intended to explain the basic optical design issues: http://www.quarry.nildram.co.uk/Binocs.htm

Tony Williams: Military gun and ammunition website and discussion forum

Here's all the info you'll ever need.

http://www.usoptics.com/optics101.php

http://www.quarry.nildram.co.uk/Binocs.htm

Geez, the very first sentence is in error.

Dakota summed it up up as well as anyone can. The only thing I can add is if dollars aer an issue is to go wih a quality fixed-power rather than a mediocre variable............Essex

Geez, the very first sentence is in error.

http://www.quarry.nildram.co.uk/Binocs.htm

Click to expand...

??? Is that meant to be a joke, or something?

Tony Williams: Military gun and ammunition website and discussion forum

don't forget about "paralax"

...theory is that 30mm can transmit more light to the eyepiece so they are brighter.

Click to expand...

Light transmission (perceived brightness) in a function of the objective size, NOT the tube diameter, regardless of the size of the internals.

Don

No, Tony, no joke. Most people probably own a binocular, not a pair of binoculars. The word is “binocular,” not a “pair of binoculars,” which means two binoculars. The prefix “bi,” from the Latin bini, means double or two. Add it to “ocular,” from the Latin oculus, meaning eye, and you’ve described a two-eyed instrument. A binocular.

I just wrote an article on optics for "practical long range rifle shooting", which might or might not match your intended use. Article available here: http://demigod.org/optics

No, Tony, no joke. Most people probably own a binocular, not a pair of binoculars. The word is “binocular,” not a “pair of binoculars,” which means two binoculars. The prefix “bi,” from the Latin bini, means double or two. Add it to “ocular,” from the Latin oculus, meaning eye, and you’ve described a two-eyed instrument. A binocular.

Click to expand...

Maybe it's a UK vs US English usage thing: I've never heard anyone refer to 'a binocular' here in the UK and I've been around them long enough - it's always 'a pair of binoculars' or maybe just 'binoculars' (meaning one instrument).

Do you refer to 'a trouser'?

Tony Williams: Military gun and ammunition website and discussion forum

Light transmission (perceived brightness) in a function of the objective size, NOT the tube diameter, regardless of the size of the internals.

Click to expand...

A larger objective will allow for a larger exit pupil (assuming the rest of the optic is designed correctly!) which, up to a point, will make the view through the scope appear brighter, all else being equal.

But as the term is generally used, "transmission" normally refers to the percentage of the light that enters the optic which ultimately exits the optic. This is a function of the AR coatings on the glass and the internal transmission of the glass . . . towards the edge of the field, vignetting may play a role as well. (The area taken up by the reticle is usually not considered.)

The best 'scopes will transmit well over 90% of the light entering them.

theory is that 30mm can transmit more light to the eyepiece so they are brighter

Click to expand...

Then theory is wrong. Light going through an optical train doesn't behave like water going through a pipe. Under everyday conditions, a smaller lens can transmit just as much light as a larger lens.

It's a colloquial vs. proper English thing, not a UK/US thing. Kinda like ending sentences with prepositions, or using "they/their/them" instead of "him" or "him or her" or "one" to describe a gender-independant person.

Binocular in the singular is usually used as a more general term meaning having or accommodating two eyes, or something similar.

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Agreed: we use it as an adjective, as in 'binocular vision' or a 'binocular eyepiece' for a microscope, but the noun is always 'binoculars'.

Tony Williams: Military gun and ammunition website and discussion forum

The fact that so many people misuse it does not in any way make such misuse correct.

From Webster:
Main Entry: 2bin·oc·u·lar
Pronunciation: b&-'nä-ky&-l&r, bI-
Function: noun
1 : a binocular optical instrument
2 : a handheld optical instrument composed of two telescopes and a focusing device and usually having prisms to increase magnifying ability

Although even Webster recognizes that it's commonly used in the plural, it doesn't legitimize it.

In this case, it's easy to see why it's always singular when referring to one object. But in other cases, why is it a pair of pants, but only one bra?

In this case, it's easy to see why it's always singular when referring to one object. But in other cases, why is it a pair of pants, but only one bra?

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Or a pair of scissors?

The only answer is: don't look to English for logical consistency. I'm pleased I grew up learning it because I'd hate to have to start from scratch :banghead:

Tony Williams: Military gun and ammunition website and discussion forum