The 7 is the magnification produced - it is a ratio of the focal lengths of the lens at the eyepiece and the front (objective) lens.
The 50 is width of the objective lens - in millimetres.
It depends on the specific needs and preferences of the user. 16x50 binoculars provide higher magnification for more detailed viewing of distant objects, but may have a narrower field of view and be more prone to image shake due to the higher magnification. 10x50 binoculars offer a wider field of view and are usually more stable, which can be better for general use and birdwatching.
Infrared binoculars are available to the general public but are generally more expensive than conventional binoculars. The cheapest go for about $75 and can be as expensive as $600.
Yes they do. The important feature is diameter of the front lenses, these collect more light than you can get in through the unaided pupil of your eye. Therefore binoculars gather more information about what you are looking at than your eye can and you can see things with them that the unaided eye can not see. To test this go out on a clear night and point your binoculars at the sky, they will show you stars that you can not see without them. However, this light gathering power means you MUST NEVER try and look at the Sun though binoculars, if yo do so you will immediately be blinded.
The 10x means it magnifies ten times The 70mm means the final lenses (that point to the image) are 70mm in diameter. The larger the diameter, the more light that can enter the binoculars and so the easier it is to see the image. So binoculars 10x50mm and 10x70mm both magnify ten times, but the 70mm diameter lenses allow more light in and so should give a better image. So the larger the second number, the better the image [should be] for a given magnification; however, the larger the second number the larger (and heavier) binoculars become.
In the case quoted, 10 is the magnification factor of the binoculars. In other words, objects appear to be 10 times closer viewed through the binoculars compared to with the naked eye.
It depends on the specific needs and preferences of the user. 16x50 binoculars provide higher magnification for more detailed viewing of distant objects, but may have a narrower field of view and be more prone to image shake due to the higher magnification. 10x50 binoculars offer a wider field of view and are usually more stable, which can be better for general use and birdwatching.
Infrared binoculars are available to the general public but are generally more expensive than conventional binoculars. The cheapest go for about $75 and can be as expensive as $600.
Binocular telescopes, with interchangeable eyepieces, can have a focal length as long as you like. Generally, any binoculars that advertise based on the magnification will be useless, as the picture quality will be unbearable. Also, binoculars with more than 15x can be hard to hold. It is better to get a good pair of 8 or 10 x binoculars with a larger front element. If you really want though, it does not get much more powerful than this: http://www.overstock.com/Sports-Toys/Full-Size-Zoom-Binoculars/2866058/product.html 120x
Yes they do. The important feature is diameter of the front lenses, these collect more light than you can get in through the unaided pupil of your eye. Therefore binoculars gather more information about what you are looking at than your eye can and you can see things with them that the unaided eye can not see. To test this go out on a clear night and point your binoculars at the sky, they will show you stars that you can not see without them. However, this light gathering power means you MUST NEVER try and look at the Sun though binoculars, if yo do so you will immediately be blinded.
Some are very close to earth, and others are much farther away. This is why only some ranges of binoculars can see farther into the night sky than other, ordinary, binoculars.
more than you have
The 10x means it magnifies ten times The 70mm means the final lenses (that point to the image) are 70mm in diameter. The larger the diameter, the more light that can enter the binoculars and so the easier it is to see the image. So binoculars 10x50mm and 10x70mm both magnify ten times, but the 70mm diameter lenses allow more light in and so should give a better image. So the larger the second number, the better the image [should be] for a given magnification; however, the larger the second number the larger (and heavier) binoculars become.
In the case quoted, 10 is the magnification factor of the binoculars. In other words, objects appear to be 10 times closer viewed through the binoculars compared to with the naked eye.
Yes, binoculars use similar lenses to telescopes but with a system of prisms to fold the light path to permit binoculars to be much shorter than a regular telescope.
Binoculars are shorter than telescopes because of the prism located in them that shorten the length of the light waves. The lens in the tubes of the binoculars allows for the magnification of the objects seen in the distance.
Binoculars are distinguished from telescopes through the use of "folded optics". That is, the light path is folded into the body, allowing a compact design. Rather than mirrors, prisms are used to reflect the light.
If you are hunting a spotting scope is very useful. On the other hand if you are just bird watching or enjoying the sites it can also be nice to have, they tend to be better than binoculars and lighter as well.