[birdman]

Binoculars are wonderful pieces of equipment that can enhance many of our daily activities including, birding, action sports, hunting, and even astronomy. Essentially binoculars take a distant image, enlarge it through the use of lenses for viewing, all while remaining small and light enough to be mobile.

The actual makeup of most binoculars is fairly straightforward and simple. You have the lenses at the end of the barrel called the objective lens that gathers the light from the distant image and focuses it on the lens closest to your eyes for viewing. Binoculars are really two small telescopes put side by side so that you can view the desired image with both eyes instead of just one. This imparts some measure of depth of field, much more so than with a single scope.
When selecting a pair of binoculars you will immediately find that two numbers are used to describe their capability. These numbers are often expressed as “6 X 30″ or something similar. Let’s break the code so you will know what these numbers mean.

The first number refers to the magnification power of the binoculars, or in other words how many times the image is magnified. So if the number is 6, that means that the image that you view through the lens is magnified 6 times it’s normal siZe. The second number has to do with the size of the objective lens at the end of the binoculars.It’s good to know this number because the larger the diameter of the objective lens, usually the more light will be let in for viewing the distant image.

Now, let’s put this information in use in the real world. You may think that it’s best to just get the highest magnification that you can get for binoculars, but this is not true. At some point, hand holding the binoculars will affect the clarity of a highly magnified image and the resulting shake will render the magnification benefits useless. Generally speaking, anything above ten times magnification should be mounted on a tripod instead of handheld. So if you are planning to use binoculars for activities that do not allow you to be able to bring along a sturdy tripod, you probably want to stay with a pair of binoculars with 4 -7 times magnification.

As far as light gathering properties are concerned, if you plan on using your binoculars in any kind of low light situation whether indoors, or at times of day when there is low available light outdoors, then you need to have a large objective lens, usually 30 or above, to make as much use of available light as possible.

Finally, consider the weight of the binoculars before buying them. If weight will be a consideration for activities such as hiking, then perhaps plastic lenses will be best that are specially coated to produce a high quality, sharp image. These can be more costly than glass lenses, but they are considerably lighter. Glass lenses usually make for much better optics and clearer images at a lower overall cost, but they can also be more fragile.

Generally speaking, more expensive pairs of binoculars have more atention paid to fit and finish and will stand up to more vigorous use, but if you only plan to occasionally use your binoculars, then a less expensive pair will no doubt work fine. Also, remember that after the purchase you should be sure to protect your investment with a suitable binoculars case.

[stalkingbear]

Very well written birdman. There's a couple areas I would like to touch on in addition within my extremely limited knowledge.
To begin with,when choosing binos,you have porro prism and roof prism. The difference between these 2 styles may affect which the individual should choose. Porro prism means the image is reflected/transmitted inside by changing direction at 90 degree angles thereby the phyical size will be bigger and heavierthan comperable roof prism binos. Porro prism binos do offer better quality per dollar than do roof prisms. That means that with both styles equal optical quality,the porro prisms will be slightly cheaper. Roof prisms are easily identified by the straight "barrels" or tubes,and are usually smaller and lighter in weight as compared with porro prisms but cost more for same quality. Both have their uses and both styles are useful in all hunting situations within their perspective sizes.
The other area I feel need discussing in order to choose the right binos for YOUR uses is exit pupil. Since the average human eye pupil dialates to about 5mm-5,5mm in low light (approx 7mm in complete darkness),it makes sense to choose binos that offer this size exit pupil unless they're going to be used in good light. Exit pupil is simply the diameter of the view or light transmitted thru the optical instrutment at the distance where your eye is from it. To determine exit pupil size,take objective (front) lens size in MMs and divide by the power of magnfication or Xs. That means a pair of 8x binos with 40mm lens will have a 5mm exit pupil because 8 will go into 40 5 times. You'll know instantly if the exit pupil on your binos or scope is too small because at a certain point in low light,it'll appear to suddenly "black out" or go dark. This is often encountered with smaller "pocket handy" binos OR with adjustable power when the power is turned up too high.
In addition to the optical quality of the lens themselves,better binos will offer more precision and better anti-reflective coatings on the lens-both inside and out. The quickest way to tell the quality of any optical instrument is the resolution factor. Resolution is nothing more than your ability to distinguish detail. The higher the resolution factor,the smaller objects you'll be able to see. A good example of this is reading printed words in distance. the smaller words you can read on a sign or something with words on it in the distance or the farther you can read those same words means higher resolution factor. resolution is not about magnifation but about the sharpness in which the images appear. many people choose cheaper optics and have to opt for more power in attempt to make up for lower resolution. This will only lead to headaches from eye strain as well as smaller field of view.
As a given,lower magnfication or larger objective lens will produce wider field of view. This is especially important when hunting and you don't have much time to evaluate the game to determine wether you want to harvest it or not.
Guess that's about all I have for now. Neil

[birdman]

Very nice additions Neil!!!! I don't think people spend enough time choosing the correct specs for themselves. I've found the most important aspect for me is to prevent eye fatigue by choosing a high resolution type.