Using Your New Binocular
By Mohonk Preserve Director of Conservation Science Elizabeth Long
and Mohonk Preserve Research Associate Zach Smith

You’ve read different bits of advice, scoured the internet for reviews and bargains, tried out several models, and now you’ve made your choice: a new binocular for hawk watching. Here are some tips on how to use your new tool effectively, how to keep it in good condition for as long as possible, and what to do when you eventually notice it getting a bit long in the tooth.
1. Check your width
The first thing to notice is that your binocular consists of two barrels connected by a hinge mechanism. This hinge allows you to adjust the width between the two barrels to comfortably accommodate the distance between your eyes. A binocular that’s sitting in your pack or hanging by a strap from your coat rack can get jostled and can shift, so it’s worth very quickly checking this width each time you start a new session of birding or hawk watching.

2. Invest in a new strap
Speaking of the strap, most binoculars come with a factory-supplied strap that’s designed to hang around your neck. We strongly recommend making a small investment into a new strap- the short straps that come with most binoculars place a tremendous amount of stress on delicate human necks. The best case scenario is that your neck gets sore quickly- the worst case scenario is that you throw something out of whack and actually strain something. Many serious birders prefer to use a system that hooks over both shoulders and goes across the chest, so that the weight of the binocular is not hanging off the neck. These are commonly referred to as “binocular bras.” Another alternative is a very long strap that hangs crosswise over one shoulder, bandelier-style. If you go for the latter option, be sure to alternate shoulders periodically to give your muscles and joints a rest.
3. Positioning the binocular
Are you having trouble finding the image when you look through the lenses? Is it just a black void? You simply need to position the binocular correctly in front of your eyes to make the image visible. For almost every binocular user, the best performance will NOT come through pressing the lenses flush with the eye sockets. You’ll notice that your binocular has a device around each eyepiece that is adjustable- either a circle of soft rubber that can be folded down, or a cylinder of hard plastic that will screw up or down. These eyecups can be adjusted for users who wear glasses (screw or fold your eye cups down) or are looking through a naked eye (screw or fold the eye cups into the fully extended position). Next, hold the lenses to your eyes and experiment with different positions, angles, and distances from your eyes. When you hit the sweet spot, the there will be no black void, just the clear image of what you’re observing. For example, Elizabeth doesn’t wear glasses, so she keeps the soft rubber eye cups unfolded (fully extended), and she finds that the best position is with the top of the eye cup flush with the top of her eye sockets (just under her brow bone) and the bottom of the eyepiece slightly away from her face.
4. Focus
Folks who are new to binocular use often find the most challenging step to effective birding comes when they need to focus. Your new binocular will have two (or possibly three) focus knobs: a main focus knob between the two barrels, and a diopter focus knob (or knobs) on one (or both) eyepiece(s). This might seem complicated, but it’s incredibly valuable, since most humans have different vision in both eyes. The diopter focus mechanism allows you to accommodate this difference in your eyes, and customize the binocular specifically for your vision.
Here’s how to focus if your binocular has just one diopter (most common): determine which eyepiece has the diopter (right or left). Hold the binocular up to your eyes and close the eye with the diopter (e.g. on Elizabeth’s binocular the diopter is on the right, so she closes her right eye first). Pick a spot in the distance and focus on it using the main focus knob. Once it’s in sharp focus, close that eye and open the other (so Elizabeth closes the left eye and opens the right). Now adjust the diopter knob until the image is in sharp focus through that lens. Once you’re happy with that, open both eyes- the image should be in sharp focus!
Here’s how to focus if your binocular has two diopters: set both diopters at their midpoint (most will have some type of measurement, either numbers, a plus/minus system, or some other type of marking). Shut your right eye, look through your binocular, pick a point in the distance, and adjust the main focus knob until the image is sharp. Then close your left eye, open your right, and adjust the diopter until the image is in sharp focus. When you open both eyes your image should be sharp.
Be sure that during the process you are standing still so that you are a consistent distance away from your focal point. You should also take care to make sure that you aren’t adjusting the distance from your binocular to your face as you switch between eyes. Take care to make your adjustments holding your binocular at its optimal distance from your face.
5. Now you’ve got it working, let’s keep it in good condition!
Well-made binoculars are designed to hold up to rugged outdoor use, but even the sturdiest binocular is susceptible to the elements or rough handling. There are four hazards that can doom your new favorite tool: water, sand/dust, scratches on the lenses, and impacts with a hard surface.
If you invested in a decent binocular it should be water resistant. Using the binocular around water like a stream, lake, or ocean should not pose any problems. Spilling liquid on it or dropping it into a water, though, can allow water to get inside the barrels and fog the lenses. This is a disaster for your binocular, and will require professional repair, so avoid it at all costs! Using your binocular in humid environments like rainforests, or during rainshowers, can be tough on them, but a good binocular should be up to the task. Still, try to keep the unit as dry as possible and take a moment to gently blot off any water with a soft towel.
Bird watching at the beach can be a fantastic experience, but it can be rough on your binocular. Not only can sand scratch the lenses, but it can get into the mechanism and impair the focus knobs or even the prisms on the interior of the barrels. The same is true of fine dust, so take great care when using binoculars in these environments.
The lenses on your binoculars are inevitably going to get dirty, and you should take care to clean them regularly. Not only will visibility be better, but keeping them clean reduces the likelihood of scratches that can be catastrophic. For a few dollars you can get a soft lens cloth — rougher fabrics, like your t-shirt, can scratch, particularly if there’s grit on the lens, and tissues can leave dust and fibers on the glass.
Even the most careful among us is bound to drop their binocular at some point. Most binoculars can withstand a few jolts, but a hard impact can knock the alignment out, resulting in double images and/or an unsynchronized focus mechanism. Be gentle with your binocular!
6. What to do when you notice a problem?
Even the most rugged binocular, cared for by the most conscientious of user, will eventually start to show some wear and tear. Don’t despair! Many issues can be repaired for a reasonable price. Particularly when you purchase a really high-end binocular, it might be good practice to schedule a service for your binocular every few years just to keep everything in good shape. Contact the manufacturer of your binocular, and ask them about their repair service. Most companies will repair binoculars for a moderate fee, and if not, they will refer you to a reputable alternative.
Some of the common issues to plague well-used binoculars are a lack of synchronization in the focus mechanism (e.g. the diopter and main focus are no longer working well together); scratches to the lenses; or misalignment of the prisms and lenses inside the barrel, resulting in a double or misaligned image. You may also find that some grit has gotten into the focus knob or the hinge- it’s usually worth having that repaired, as the problem is likely to get worse over time and may even result in lasting damage to the mechanism.
A good binocular can give you many years- or even a lifetime- of use. Take the time to learn how to use it and care for it properly. It’s worth the investment!