How Far Can You See With 12×25 Binoculars?
There are a lot of factors that determine how far a pair of binoculars can see. With binoculars, you can see celestial objects hundreds of thousands of miles away, and you can also see animals a few miles away. Factors such as atmospheric conditions, the weather, and brightness, among others, will affect how far you can see with the 12×25 binoculars.
The 12×25 pair of binoculars falls in the class of compact binoculars, seeing that its objective lens is less than 30mm (it is only 25mm). The first number in 12×25 refers to the magnification of the binoculars, while the second number refers to the diameter of the objective lens.
At 12X magnification, it means that this pair of binoculars enlarges the object under view 12 times, or brings the image 12 times closer than an unassisted eye would. This magnification is higher than most other binoculars that are either 8x or 10x. However, higher magnification means a smaller field of view.
Because the magnification of this pair of binoculars is higher than 10x, it makes steady viewing a challenge. If you are moving, say you are in a boat or a moving van; the binoculars might not be steady enough to allow you to view images far away.
Field of View
At 12x magnification, the field of view narrows significantly. A narrow field of view makes it difficult to locate small and mobile objects when you are scanning from hundreds of kilometers. Again, the smaller field of view means less light gets in through the optics, and the images appear darker.
However, other factors determine the field of view of binoculars. The eyepiece design plays a role in determining the field of view. It shows the area you can view, 1,000 yards from where you are. For instance, the eyepiece can show specs as 90 feet wider at 1,000 yards.
The Diameter of the Field of Objective Lens
The 12×25 binoculars is a compact unit. This means that it is small and light, and fits in small backpacks. However, with the diameter of the objective lens at 25mm, the binoculars limit the amount of light that gets in through the optics. There are binoculars with diameters bigger than 40mm, making them show brighter images than the 25mm unit.
However, some 25mm binoculars might have high-quality optics that make them show bright images even with the small objective lens.
The exit pupil also determines the amount of light that gets through the optics. With the exit pupil, a higher number means brighter images, if you are viewing in low-light conditions. A higher number also means that the object will still be bright even if your hand shakes.
The size of the exit pupil is the result of dividing the diameter of the field of view by magnification. For instance, with the 12×25 binoculars, the size of the exit pupil is approximately 2mm. This is low compared to a pair of binoculars, say 8×42, whose size is 5.25mm. This number indicates the size of the shaft of light that gets to your eye. The pupils of your eyes will vary between 2mm in bright light and 7mm in a dark situation. In dim lighting, the 12×25 will not let you see far, thanks to the small size of the exit pupil.