Uses
You shouldn’t get a pair of binoculars that gets foggy or is affected by the rain if you’re going somewhere with high humidity and precipitation. You never know when it’s about to rain in some places and if you’re somebody who’s always outdoors like me, any binocular other than the waterproof binocular varieties is a terrible choice.
If you intend to use your binoculars at theaters or watching sports matches, you probably shouldn’t get one with high magnification as that’s really not needed in those places. If you go around hunting or bird watching often, looking at image-stabilized binoculars with high magnification is worth it.
Binocular Specs and What They Mean
If you’re new to binoculars and have ever looked up reviews or specs on binoculars, you’ve probably noticed symbols and numbers. You may have wondered what they could mean.
If we’ve got a binocular that says 10×50, the number on the front means the magnification that the binocular provides. 10 in this case. The second number after the x means the size of the lens in millimeters. 50 mm in this case.
So, 10×50 just means the binocular has a 10x magnification (more on magnification in the section below) and a 50mm lens.
Magnification
Magnification is how big something looks through the lens in relation to the naked eyes.
Still, confused?
Think of it like this- if you use a lens to look at things, it just makes things appear bigger. If something has a 3x magnification, it just means that anything you look through it appears 3 times bigger.
The magnification of binoculars usually ranges between 7x-10x. Somebody who casually uses a binocular for watching a movie or sports, or a child looking at the birds on a nearby porch would be very happy with 7x magnification. Others- like hunters or researchers who need to look at finer details may need binoculars with 10x magnification or even higher.
However, going higher is not always better as more magnification means that you are only looking at a smaller area and if your binocular isn’t very stable, what you see will be very shaky.
Apart from binoculars with fixed magnification, some let you adjust the magnification within a certain range. These are called Zoom binoculars and come in very handy as they bring out the best of both worlds.
Magnification of Zoom binoculars is shown as 5-24x, and these numbers represent lower and higher magnification respectively. Since the optics of these binoculars is constructed to work best at a particular focus, you may lose some clarity in other settings.
More magnification power isn’t always good per se as they tend to be in the upper price range. If you’re looking for affordable binoculars (I know I am!) that feel and perform great, you’ll have to stick to low magnification binoculars.
If you are unsure about which one you should get, just go for one in the 8x-10x range.
Optics
The size of the lens is a determining factor in how bright an image will be. A wider lens allows more light to pass through and as a result, improved viewing conditions. The size of the lens also has nothing to do with the field of view.
A bigger lens means that it will produce crisp clear images but the binocular will be heavier as a result.
Wondering about the field of view? A field of view of 5-7 degrees is considered pretty standard on normal binoculars and anything larger than 7 degrees is said to have a wide field of view.
As magnification goes on, the field of view goes down as there is less to see. What this means is that, if you are trying to see a large flock of birds, you’re better off with lesser magnification as this would mean that you don’t have to move your binoculars to see from end to end.
Binoculars are made out of optical parts that can reflect light – sort of like a mirror. Any reflection within the binocular means that there will be a loss in brightness.
So, every air-glass surface on the best binoculars is coated with an anti-reflective coating. Coatings can be expensive, so there are a variety of options to choose from.
There’s the full coating which means that all surfaces are coated. And there’s full multi-coating which means that the surface has been coated several times. Fully multi-coated ones are great, but these tend to be pretty expensive too.
Eye relief is also something that binocular-enthusiasts talk about pretty often. It just means the distance between the lens and your eyes. Longer than 13-15 mm is considered long eye relief. Less than that, and you’ll regret buying the binocular if you regularly wear glasses.
Having a long distance in front of your eyes means that you can use binoculars comfortably even when wearing glasses. In fact, the optics community is big on helping guys with specs use binoculars as conveniently as possible.
The size of the lens is also important when it comes to what purpose it will be used for. A smaller lens allows less light to pass as compared to a large one, and so, won’t be as bright as a binocular with a large lens. So, smaller binoculars work well as portable ones for use in the daylight and larger ones are great in low light and poor viewing conditions.