Question about binoculars (model, watch, walking, sports)

[ansky]

I'm looking to buy my first pair of binoculars. There is one pair I like that has several sizes to choose from. 10x50mm, 12x50mm, 20x50mm. Can someone tell me what those numbers mean? If I'm looking at something far away would the 20x50 size bring it closest?

[ferretkona]

The first number is the amount of magnification, larger number means more magnification. Variable power is available.
The last number is the size of the glass you are looking thru. Not the lens you look thru but the larger of the binoculars.
Their are some fine glasses made small to fit in a pocket, 10 x 20mm.
I carry two in my truck, Nikon Compact Zoom Binoculars, 8-24X25 and Nikon Monarch 3 Binoculars, 10 X 42

Binoculars with high power can get frustrating to use as any movement can loose your focus. Many people use a tripod mount to steady them.
We now have digital binoculars with built in steady cam. They also record for later viewing. These are good for use on boats as the water can create too much movement.

[Mr. In-Between]

The firs number is the magnification, the second is the diameter (in millimeters) of the objective lens, the lens in the front of the binoculars. That second number gives you an indication of how much light is being let in. So a 10x is going to be more powerful than an 8x, and a x42 is going to let in more light than a pair of X35. By dividing the first number into the second, you get a number that tells you the diameter of the "exit pupil" - which is the diameter of the image that comes out of the eyepiece at the rear of the binocular.

So, an 8x32 (with an exit pupil diameter of 4) is going to be more powerful, but a 7x35 (with an exit pupil of 5 millimeters) is going to have a brighter, and often clearer and even sharper image - all other things, such as optical quality, being equal. This is useful to a degree, but only to a certain extent, because binoculars vary widely in terms of the quality of the lenses and the lens coatings. A really good pair of 8x32s can give you a noticeably brighter and clearer image than a $40 pair of 7x35s. It is a good number to keep in mind, though, because generally speaking, the larger the exit pupil, the better the image in low light conditions. An 8x32 will usually give you a more than adequate quality image in open country in the daylight compared to a 7x35, but if you're going to be using them in the deep woods, the brighter 7x35 will usually give you a better look at that bird than the slightly more powerful 8x32s. In your specific example, the 12x50 is going to be somewhat more powerful than the 10x50, but the image will not be as bright - whereas the 20x50 will be much more powerful but the image will be noticeably less bright and clear than the others.

Keep in mind also that generally speaking, the more powerful the binocular, the more narrow the field of view. And, the more powerful the binocular, the harder it is to hold it steady when you're marching around in the woods or otherwise exerting yourself. Most people can comfortably hold a steady image with a 7x binocular when out in the field, but many people start to have trouble holding the binocular steady even at 8x, and most people using a 10x in the field need a tripod or at least a tree to brace against if they don't want the image to jitter a bit. And a 20x on a hiking trip? Forget it. You're going to need to carry a concrete block to set it on.

So that's the basics of the numbers, but it leads us to the question of how are you going to be using them? That matters a lot. There is no such thing as a "best binocular;" there is only the best binocular for your particular use. Are you a birdwatcher? Hunter? Boater? Astronomy buff? Sports fan? Opera buff? Someone who sits in the kitchen and looks at the wildlife in the backyard? All of those people are going to look for different things in a binocular.

A boater, hunter, or even birdwatcher will probably want water resistant or even waterproof binoculars, but the boater is probably going to want the most powerful binocular he can get regardless of the exit pupil diameter, whereas the hunter and probably birdwatcher are going to want the larger objective lens so that they can see better in the woods. The hunter is still going to want as powerful a pair as he can afford, but the birdwatcher may be willing to give up some power to get an even brighter, clearer image. The guy who just keeps a pair of binoculars on the kitchen table is probably going to spend his money on magnification and image quality, with no regard for whether they are water resistant.

One final thing to keep in mind is the design of the binocular. Do you want full size, or compact? Full size almost always give you a brighter, larger, and sharper image than a compact, but they are heavier and harder to carry. But if you're going to be using them at concerts or sporting events, the compact is usually the better choice.

Also, keep in mind the difference between porro prisms and roof prisms. Porro prisms, where the internal lenses, prisms, and mirrors are offset in the space between the front and rear of the binocular, is the standard, classic design. You'll generally get better image quality, a wider field of view, and better depth perception in a porro prism. A roof prism is a design in which the front and rear lenses are almost exactly in line with one another, a "straight through" design. These are generally more rugged and durable, and less likely to get knocked out of line if you drop them, more streamlined, and usually more likely to be waterproof than the average porro prism - but they're more difficult to design and manufacture, and are usually more expensive. Unless you're going all Rolls Royce with a Leica, Zeiss, or Swarovski, you'll usually get a better binocular for your dollar with a porro than a roof prism design. Stay away from cheap roof prism binoculars, no matter how well-produced the commercial is - it's the optical equivalent of going shopping for a cell phone and coming home with two cans tied together with a piece of string.

The last thing I'd tell you is that before you buy any binocular online, go to a store that sells them and look at them yourself. See how they feel in your hand, and compare them side by side with different designs and similar binoculars from other manufacturers, because there really is a lot of difference from one to another. Before you spend your money, make sure you know what it is you're getting, and what you could have had instead for another 10 or 20 bucks. A cheap pair of binoculars form a magazine ad or late night TV commercial may be fine for someone who doesn't use them very often, but a serious birdwatcher is never going to be happy with them.

Oh, one other thing - if you do buy in a store, make sure you research everything the sales person tells you. Binoculars are a high-spiff item, which means most salespeople get a really high commission for some binoculars. For example, they may make as much as 50 bucks for that pair of Nikons they sold you, but if you'd bought the much better pair of Swifts, they'd have only made 10. Which one do you think they're going to push you toward? Anytime you're dealing with a camera or binocular salesperson, trust but verify. Don't be afraid to make a second trip to make sure you're getting the pair that's best for you. And if you are planning to buy in a store, keep in mind they're almost certainly going to be much cheaper a month from now. They're one of the first things that go on sale the day after Christmas. That's not to say you can't get some really good deals on pre-Christmas sales, but you're more likely to get more for your dollar in January, when most people walking into the store are making returns rather than actually spending money.

[ansky]

Thanks for all the information. I decided on this pair from Amazon:

http://www.amazon.com/gp/product/B00...ilpage_o00_s00

I don't know if the 10x magnification will be too strong, but I figured I would rather start higher and return them if I need to.

[Mr. In-Between]

Oh, wow. Now I see. Bushnell's, eh?

I don't know much about that model, but I used to sell binoculars and telescopes for a living, and I do know a few things about Bushnell - if it hasn't changed much in the last 15 years or so.

First of all, I think you're getting great value at that price point. You could have spent more and gotten a better binocular, but you could have also spent a lot more and gotten a much worse one. If that's your price point, you probably did very well.

Bushnell is probably a mid-level binocular, but definitely upper mid-level IMO. Like most mid-level products, they have their strengths and their weaknesses. If nothing's changed much since I sold them, the biggest weakness is the construction - they aren't always put together in a really sturdy fashion. You want to be careful about dropping them, but the upside is that's where you're saving all the money.

They don't shortchange you as much on the optics. It's not a Zeiss or a Leica, but that's not the kind of binocular you need, and you could easily spend double on a "better" binocular from one of the major manufacturers without getting any better optics. As long as you treat them gently, and keep them out of the rain (never did trust even their "weather resistant" binoculars in the rain), you'll probably be very happy with them. Enjoy!

One thing you might want to check into when you get them - are all the lenses glass, or are they using plastic on the rear lenses? If they are, you're going to need to be even more careful than you would otherwise be not to scratch them. Just something to keep in mind.