Navigating the rivers of Size and Weight can be challenging but are important considerations. Compact binoculars offer smaller size and weight advantages, while full sized have greater light gathering capability but are heavier.

To enhance light transmission through a binocular, manufactures apply a microscopic film of magnesium fluoride either to the prism, lens or both. This microscopic film diminishes the reflected or stray light inside a binocular allowing more light to be transmitted to the users eye. The more applications of this coating, the greater the reduction in glare and reflections producing a brighter crisper image.

The least expensive process is known as a "coated" optic where only the prism is coated. "Fully coated" optics are when all air-to-glass surfaces (lens and prisms) are coated once. The best coating available is "fully-multi coated" where all air-to-glass surfaces are coated multiple times for the greatest amount of light transmission to the eye.
TIP: More coatings mean brighter, crisper images.

When viewing through a binocular the visible width at a given distance is known as the "field of view". Field-of-view may be expressed in feet at 1,000 yards, meter at 1,000 meters or degree of angle. One degree of angle equals 52.36 feet field-of-view at 1,000 yards. An optic with 6.5 degrees of angle can be calculated by multiplying 52.36 feet. (6.5 x 52.36 = 340 feet at 1,000 yards).
TIP: Field of view will decrease when magnification is increased.

The distance from the ocular lens to the point where the users eye can see the full image (focal point) is known as "eye relief'. If you wear eyeglasses and experience "tunnel-vision" when using your binocular you need extended or long eye relief. Binoculars made for eyeglass wearers should offer a minimum of 18mm of eye relief. Eye cups that are adjustable or "pop- down" can be used by both eyeglass and non-eyeglass users.
TIP: Eyeglass wearers should seek a binocular with a minimum of 18mm of eye relief. More is better.