Arizona Hunting Club & Outdoor Adventure Group

Using Hunting Binoculars to Locate Deer and Elk

The most important tool for every hunter is a pair of good binoculars. A high quality binocular will let you see twitching ears, antler tips and identify trophy bucks and bulls from hundreds of feet away. If you have time to scout before the seaoson use binoculars and a spotting scope to scout hillsides from below and elevated position like the Mogollon Rim, which is great for spotting both deer and elk from above.

The good news for hunters is that high-tech optical coatings and new manufacturing methods have improved the performance and lowered the price of high-quality binoculars and scopes.

Binoculars are an indispensable tool for hunters. Walking and stalking with a pair eyes that can see several hundred yards or more will be the difference between you walking around in the forest and swearing to yourself that there are no animals in this area and to magically seeing deer and elk that are bedded down before they smell and see you and quietly slip down a draw and around the backside of the mountain.

Binoculars come in a wide variety of shapes, sizes and specifications. Most are multi-purpose instruments, suitable for a number of different activities including deer hunting, elk hunting, antelope hunting and more. Because of their large light-gathering capacity and the typical wider spacing of the lenses than the human eye, binocular images are brighter, more detailed and more three-dimensional than normal vision. Since no one particular binocular is perfect for all situations, determining their primary use is one of the most important factors in choosing the right one for your needs.

Remember, that there is no one binocular that will best meet the needs of every situation. Often, compromises have to be made among the various features and specifications. Of all the different types and styles of binoculars available, only certain models represent the best value in terms of optics, construction, manufacturer support and overall performance.

Binoculars are described with two numbers with an "x" between them such as 7x35 or 10x42. The first number refers to the magnification power of the binocular. The second refers to the diameter of the front lens (in millimeters). A larger diameter lens means more light can enter the binocular and the image should be brighter.

Hunting Binocular Magnification

Generally, the range in magnification for hand-held binoculars is from 6 to 10 in power. In a binocular designation (7 X 35, for example) the first number indicates the magnification, or how much larger, or closer, the object will appear than seen with normal vision.

When considering magnification, more is not necessarily better. As magnification increases, brightness and clarity may diminish, depth of field can become shallower and the field of view is usually more restricted. More noticeable and disturbing at higher powers are fine hand tremors and the effects of atmospheric conditions, such as the distortion caused by heat waves.

If your observation is done primarily at close range, such as in woodland areas or in your backyard, then a good 6, 7 or 8 power binocular might be the best choice. This range of magnification generally gives you a larger picture (wider field of view) which is especially important for viewing objects relatively close at hand. Also, binoculars of this magnification usually deliver better performance under conditions of low available light, due either to the time of day, weather conditions, or shadows caused by dense vegetation or other structures. This same type of binocular also works well for fast-moving action like sporting events, since the wide field of view allows the action to remain in the viewing area.

For long distance viewing or where greater detail is required, a higher magnification of 8, 9 or 10 should be considered. For example, the demands of observing in wide open terrain with little cover are best met with a binocular of 9 or 10 power. This generally holds true for situations where there is a need for critical field mark identification, as in observing the number of points on a rack when the animal is bedded down on the other side of a canyon. Magnification, as a binocular parameter, should be considered as it relates to other factors such as aperture size, exit pupil, hand-held stability, atmospheric conditions, available light, optical design and the weight of the binocular.

Hunting Binocular Lens Diameter

The second number of a binocular designation refers to the diameter, in millimeters, of the front, or objective lens. The diameters usually range from 20 to 50 millimeters and this number will almost always be directly related to the size of the binocular. So called "giant binoculars", used mainly for astronomical purposes, may have up to 70 or 80mm objectives, while compact models will usually be 20 to 25mm in diameter. The objective lens size, or aperture, determines the amount of light that will enter the optical system. The common assumption that the size of the objective lens will determine the field of view is seldom true as field of view is controlled largely by the optical design of the binocular.

A larger objective lens will gather more light and theoretically provide greater detail and clarity of the image. This is especially true under low light conditions. Since the amount of light that will enter the objective lens will vary by the square of the change in the radius, a small difference in objective lens size will have a greater impact on the light gathering ability than one might first suspect. Once the objective gathers the light into the binocular, other factors determine how much light is transmitted through the optical system and all of these factors, including the aperture, combine to determine the brightness and clarity of the image you actually see. These other factors include magnification, exit pupil size, eye pupil size (controlled largely by the amount of available light), the presence and type of anti-reflection coatings used, and the size and quality of the optical glass and prisms used in the construction of the binocular.

Hunting Binocular Eye Relief

Eye relief refers to the distance behind the binocular eyepiece at which the whole field of view is clearly visible to the observer. With binoculars, this distance will vary from as little as 5mm to as much as 23mm and it is a very important specification for those who prefer or need to wear eyeglasses or sunglasses. Unless a binocular has a minimum eye relief of about 15mm, there will be some difficulty in comfortable observing and in seeing the complete field of view when wearing eyeglasses. If an individual's eye correction is for near or far-sightedness then the binocular's focusing travel will usually accommodate for this without the need for wearing the eyeglasses. However, for moderate to severe astigmatism it is almost a necessity to wear them for serious observing.

Hunting Binocular Twilight Factor

The factor that has the greatest impact on resolution or image detail, will be dependent upon the amount of light available during the time of observation. During daylight hours, when your eye pupil size will be only about 2 to 3mm, magnification will be the principal factor in image resolution. At night, with the eye pupil dilated to 6 to 8mm, aperture size is the controlling factor. In twilight conditions both of these factors control resolution effectiveness and the twilight factor is the term that compares binocular performance under these conditions.

The twilight factor is calculated by taking the square root of the product of the magnification and the aperture. The higher the twilight factor, the better the resolution of the binocular when observing under dim light conditions. For example, a 10 X 40 (twilight factor 20) would effectively resolve better under these conditions than a 7 X 35 (twilight factor 15.4) even though the 10 X 40 has a smaller exit pupil. Remember, however, that the twilight factor does not take into account the transmittance or quality of the optical system.

The following binocular brands are currently being recommended by a number of people and organizations we know and trust. You should try them out to see which you prefer. When you are birding with a group, ask other participants how they like their binocular. Ask if you can look through them when the birding slows down. See how they feel in your hand. A Swarovski binocular will feel a LOT different than a Zeiss binocular to most folks. Binoculars can be expensive. Use this guide to buy the best binocular you can possibly afford."

Hunting Binocular Recommendations:

Top-of-the-Line Hunting Binoculars:

• Swarovski
• Leica
• Nikon
• Zeiss
• Bausch & Lomb

Hunting Binoculars Under $500:

• Pentax
• Celestron
• Eagle Optics
• Nikon
• Swift Audubon (Not for glasses wearers)

Value Hunting Binoculars:

• Nikon
• Bushnell
• Celestron