8x42 Binoculars

8x42 Binoculars

If this is the beauty pageant, numbers would mean the vital statistics. If this is real estate, numbers would mean area. But vital statistics and area are of no concern to binoculars. So what do their numbers mean?

An 8x42 binoculars does not speak about the owner's vision, nor does it describe the instrument's dimension. All binoculars are stamped with numbers at the back. The typical ones are labeled with two sets of numbers separated by an "x" in between. Those binoculars with three sets of numbers are called zoom binoculars.

The first number, the one that comes before the "x", is the magnification of the binocular. Simply put, this number describes how many times the image is enlarged. The "x" in the middle is the typical arithmetic symbol for "times". Thus, 8x42 binoculars have 8x magnification or are capable of making the image eight time nearer than it actually is.

The second number, which is actually two digits, means the diameter in millimeters of the front lens or the objective lenses. These lenses are the ones closest to the subject viewed. This number is the one that greatly influences performance. This means that when the quality and magnification is the same, the second number will be the basis for a better performance. For example, 8x42 binoculars will provide sharper images than the 8x25 binoculars.

Together, both these numbers define to us the capability of the binocular to gather light. We will know the Exit Pupil, or that small light that appears like a circle in the eyepiece through these two numbers. When you direct the binocular towards a source of light like a light-painted wall or the sky, you can see the exit pupil. If it is getting bigger, that means that your eyes are getting more light as well. This is something positive, especially if the binoculars are used in dim light.

If we divide the diameter of the front lens (second number) to the magnification (first number) we can get the corresponding exit pupil value. Hence, 8x42 binoculars mean that their exit pupils are 5.25mm.

Now that we know that the numbers do serve a purpose, it becomes obvious that magnification is not the only important aspect in selecting from among the different types of binoculars. Another thing to remember is that motion is made more noticeable as magnification is increased. Thus, 8x42 binoculars can be held but those 10x and higher would need the support of tripods. So which numbers mean the best binoculars? You do the math.