Angela's Tips for Smart Optics Shopping

Sarah Clark

Posted on July 13 2021

As the first point of contact for many Redstart shoppers, the person in charge of making sure every order gets shipped to its destination safely, and the bona fide expert in our tagline of “Optics, Gear, Expertise,” we thought that manager Angela Anderson-Beach would be the perfect source of knowledge for all things optics-buying. Her following tips answer questions that we get every day, often from customers considering their first optics purchase. We hope they’ll help you, too!

Binocular Weight

When you’re in the market for a lighter binocular, one easy trick is to look for something with smaller objective lenses. A 32mm binocular will typically weigh a bit less than a 42mm model, but always be sure to check and compare weights before taking the plunge.

A compact or pocket model will typically weigh even less than these mid- and full-sized models, but sometimes that means decreased performance. Mini bins make great backups for storing in your bag or car in case you see something interesting unexpectedly, though!

Field of View (FOV)

A wide field of view (FOV) is handy for finding and tracking birds. This is the distance from edge-to-edge that you see when looking through an optic. If you’re a less experienced birder or are shopping for a child, we often recommend getting something with a larger FOV measurement.
If you notice a number with a degree symbol on your binocular, that’s the angle of view measurement. To find the field of view in feet at 1,000 yards, simply multiply that number by 52.5.


When it comes to magnification, the higher the number, the shorter the field of view. So again, a lower magnification (such as 6.5, 7, or 8) is often preferable for new birders. Binoculars with lower magnifications are often less susceptible to blurred images caused by shaky hands, which is a consideration among many shoppers.

We often recommend 8x binoculars for birders watching fast-moving birds such as warblers, as well as those wanting an all-purpose model. For watching slower-moving birds like waterfowl and raptors, and birding in wide-open spaces, there is often a little more time to find your subjects before they disappear. Using a more magnified 10x in these instances will give you looks with better details without risking the sacrifice of not seeing the bird at all. And if you opt for a 12x or higher, you might consider investing in a tripod to support it!

Everyone has their unique needs and preferences when it comes to birding, though, so don’t feel pressured to buy models that won’t suit your birding style!

Close Focus

The term “close focus” refers to the minimum distance a subject can be before an optic can focus on it clearly. A lot of times, birders never need to have the shortest close focus possible. If you’ll be insect watching, looking at nearby birds in your backyard, or exploring boardwalks with dense, up-close foliage, something with a shorter close focus might serve you better.

Exit Pupil

The exit pupil is the pinhole through which you view a subject through a binocular. To get the exit pupil’s measurement in millimeters, divide the size of your optic’s objective lens diameter by its magnification power. Theoretically, the larger the exit pupil is, the greater the light transmission is, and the brighter the images will appear. Optics manufacturers have improved light transmission abilities by innovating lens coatings that enhance their products’ visuals, however. But an 8x42 binocular should have brighter visuals than a 10x42 binocular of the same brand and line.

Interpupillary Distance (IPD)

For birders with smaller faces and closer-set eyes, look for binoculars with a lower interpupillary distance (IPD). This measurement is the space between the center of your eyes’ pupils. You can often get your IPD from your optometrist, or enlist a friend with a ruler to take the measurement for you. Don’t forget: It’s in millimeters!

Eye Relief

If you wear glasses, make sure to shop for optics with an eye relief of 15mm or higher. This number indicates the optimal distance between your corneas and an optic’s eyepiece lens or eyecup, depending on the manufacturer. If the eye relief is too short, you might have problems with dark rings, or “vignetting,” around the full images.

Eagle Optics Warranty

And finally, we get lots of questions from birders with Eagle Optics binoculars that need to be repaired! Vortex Optics is now handling all of Eagle’s warranty services. Get more information at

This article first appeared in Redstart Birding's 2021 Optics Guide. Download the full guide here.

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