An Eye for Optics

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What to look for when hunting for a new pair of binoculars


Every hunter who has spent enough time outdoors knows how important a good pair of binoculars is in their hunting arsenal. Since my husband, Matt, and I both needed to buy a good pair of binoculars, and being a person who loves to research, I refreshed my memory on what you should look for in binoculars and what would be best for each of our specific needs. It’s important to look at binoculars as possibly a lifetime purchase and special investment. You’ll spend so many hours with them in the field and you want them to help you… not frustrate you. I hope the following information will help you on your next purchase!

The right pair of binoculars is going to be different for each person depending on several factors, but starting with what you can afford. We definitely can’t afford expensive binoculars… being a couple that hunts is absolutely wonderful, but not on the pocketbook since we need two of everything! However, now that Matt and I have worked our way up to the trophy-hunting level, good binoculars are absolutely a necessity.

When it comes to buying optics, you certainly get what you pay for, but keep in mind a $400 pair of binoculars isn’t necessarily twice as good as one that costs $200. As binoculars get more expensive, you often pay a premium for minor incremental performance gains. Plus advances in optical glass and lens coating manufacturing in the past decade have broken a lot of barriers for less expensive binoculars. However, if you pay less than $100, you are getting something of low quality and temporary. Instead, if you are able, put that money toward something that will last much longer and that you’ll be much happier with in the end.

Although marketing is very affective in the hunting community and we all find ourselves wanting name brands, instead Matt and I both chose to go with Scheels Outfitters binoculars for several reasons. For one, guarantees are not always as great as you think they are, but with Scheels, we have a lifetime guarantee and can bring our binoculars (no need to have to keep track of the receipt or box either) to our local store, face-to-face with people who already know us. Their employees have the ability to fix certain things right on site, and if not, they will send them in to the factory for us. If the binoculars can’t be fixed, we get a new set or that money back to put IMG_2970toward a new set in the store. Plus, they have the ability to sell higher quality binoculars for more affordable prices since they don’t spend the money on advertising and marketing their binoculars like popular brands. Also, of all the binocular brands there are, all come from the few, same factories… so buying popular, more expensive brands is not necessarily getting you better glass, coatings, etc. With all of these factors, plus the opinion of my dad and brother who have other Scheels binoculars and love them, this brand was the right choice for both of us.

If you have the money to spend on top-end $2,000 binoculars… great, if you have the money to buy popular name brands… great, but if you don’t, still know that you can get quality binoculars.

Researching binoculars tells me that BAK-4 prisms are the best and what you want in your binoculars (in our Scheels binoculars). They are made of superior optical glass that produces clearer images. BK-7 prisms are also used, but they are usually in lower-priced binoculars and are inferior to the BAK-4 prisms.

Lens coating
Most binoculars have antireflection coatings on their air-to-glass surfaces. These coatings assist light transmission, but you have to pay close attention to manufacturer descriptions to get the best. “Coating” means a single layer antireflection coating on some lens elements, usually the first and last elements. “Fully-coated” means that all air-to-glass surfaces are coated. “Multi-coated” means that at least some surfaces have multiple layers. “Fully multi-coated” means that all air-to-glass surfaces have received multiple layers of antireflection coatings; this is what you want in binoculars (also in our Scheels binoculars).

Everything I’ve mentioned so far are qualities that both Matt and I looked for, but now, we are splitting in our different needs, starting with magnification. Binoculars are commonly described by using a pair of numbers, such as “7×50” or “8×25.” The first number refers to the magnification/power offered (“7” or “8” times closer than the unaided human eye).

Binoculars are all about compromises and although you’d think the higher the power, the better, that is not the case. Since higher power magnifies everything, including movement, it also magnifies your own shakes and tremors. Using 6x, 7x and 8x powers are usually the easiest for most people, even with steady hands, to hold reasonably still.

Power also affects brightness. The higher the power means dimmer the view and smaller the field of view. These are important for hunting since game often moves during sunrise or sunset.

Since I bowhunt only, I can only see so far through trees in the timber anyways, making a larger magnification not as important to me. And as a woman hunter, a more compact, lighter pair of binoculars is needed. I also have bad eyesight so I have to wear contacts, but even with them I still have a blurry shooting eye from an astigmatism. This causes my eyes often to fight for “main focus” while looking through binoculars. With all of these specific needs into account, I chose 8×42 binoculars. These will give me easier viewing.

Matt, on the other hand, bowhunts as well but also shotgun and muzzleloader hunts deer. Since he hunts more open fields and will use his binoculars to scout, a larger magnification is a must. He can also handle a bit larger and heavier set of binoculars than I can and still has 20-20 eyesight, so he chose 10×42 binoculars. These will be great multi-use binoculars for Matt.

However, if you specifically hunt out West on open terrain, then you’d want to go even higher magnification than 10x.

Objective lens
The second number (ex. 7×50) refers to the diameter of the objective lens in millimeters. The larger the number for this means the more light that can enter the binoculars. However, the larger this gets, the larger and heavier the binoculars also.

Field of view
The field of view is simply the area you can see through your binoculars. It measures in degrees and the larger the number, the more area you are able to view, which is important when trying to spot animals in their environment or while they are moving. As mentioned, the higher the power, the smaller your field of view.

Exit pupil
By dividing the diameter of the objective lens by the magnification of a binocular, you can figure out the diameter of the exit pupil. The exit pupil determines how much light is transmitted to your eye. This matters because in low-light situations where the pupils of your eyes enlarge, if your exit pupil is smaller than your pupils, it is limiting your vision. So to put the numbers to this, a human’s eye pupil in excellent condition can widen to about 7mm. However, if your binoculars have only a 3.1mm eye pupil, they are limiting you quite a bit in dim light situations.

A 7×50 pair of binoculars wouldn’t limit anyone’s at all, but they also wouldn’t be compact enough for hunting. So with my 8×42 binoculars (42/8=5.25 exit pupil), I am still getting a decent-sized exit pupil as well as getting a compact binocular to fit me. Since Matt chose the 10×42, he gained magnification over me (42/10=4.2 exit pupil), but gives up more of the amount of light that can reach his eyes.

It’s also important to note that the more we age, the smaller a person’s maximum pupil size is typically (middle-aged usually max at 5mm and elderly eyes usually max at 4mm). So the older you are, the less the size of the exit pupil in your binoculars matter.

Relative brightness index (RBI)
The RBI is a bit redundant as it goes off of the exit pupil size but it helps you chart how your binoculars compare to others in dim light. It measures your image brightness and is achieved by squaring the number of your exit pupil. So mine was 5.25 and squaring that (5.25×5.25) equals 27.56. Matt’s (4.2×4.2) equals 17.64. What does this mean? An RBI of 25 or greater is considered good for use in dim light. Mine makes that cut but Matt’s doesn’t since he needed more magnification. However, some people believe the difference between an 8x and 10x is not that much of a difference to really matter, so it is all on you what to decide is more important to you.

You can’t have a hunting binocular that gives you everything… high magnification, great light, wide field of view, etc. while also being compact. When it comes to binoculars, you have to compromise on features and find what balance is right for your specific needs and field use.

While at a store, try several binoculars to get the feel and your comfort zone. Make sure to really test them out. A store employee should be directing you to a window or view across the store. Act like you don’t know much about binoculars and ask questions to see how much the person helping you truly knows, so you can properly take into account what they say. Make sure the binoculars you choose are not just waterproof but also FOG proof! And don’t forget we often have a bow, gun or call in our hands so test them all out one-handed!

Hope this information helps!