Insights for Buying Your First Spotting Scope
Posted on October 07 2021
This article by Adrian Lesak, the birding and observation manager atVortex Optics, first appeared in Redstart Birding's 2021 Optics Guide. Download the full guide here.
While binoculars may be your primary tool in the field when birding, there are frequent occasions when you find yourself wishing for just a little more reach—a little more magnification. Be it scanning rafts of sea ducks well offshore, shorebirds on tidal flats, or that falcon aerie high up on the canyon wall, there comes a time when your steady, handheld binoculars just don’t provide the detail you’re looking for. That is when a spotting scope really shines and can be a great addition to rounding out your birding toolkit.
There are a few considerations to keep in mind before diving into your first spotting scope purchase.
Foremost, always think about your primary use. Do you simply want to scan for wildlife from the back porch? Perhaps you intend to carry your scope with you on long field outings. Are you a biologist trying to discern color bands on distant shorebirds or a backyard birder hoping to get intimate portraits of the birds visiting your feeder? Different spotting scopes and the tripods you pair with them could be recommended for each of these applications and this article will help you weigh your options.
Size and Weight
One of the primary decisions to make is which size spotting scope is right for you. The size of your spotting scope is tied directly to that of one of its most important components—the objective lens. The objective lens is the large lens out front that you point toward your subject. This lens is the light-gathering aperture and the first glass element that light passes through as it enters the optical system of your scope. Holding variables like glass quality, optical design, and magnification equal, the larger the objective lens is, the brighter and more detailed the image through your eyepiece will appear—especially in difficult conditions such as poor lighting and greater distances.
Objective lenses come in a wide array of sizes expressed in diameter in millimeters and is typically the last number in the spotting scope description, for example 20–60 x 85. The 85 denotes the objective lens diameter. This number is directly related to the size, weight, and often length of your spotting scope. Typical sizes you will see are around 50mm, 60–65mm, and 80–85mm, though there are larger and smaller options available on the market. Weight of these spotting scopes can range from just over 20 oz. to well over 6 lbs. on some of the largest models. Expect a typical 65mm spotting scope to weigh around 3.5 lbs. and an 85mm scope to come in around 4.5 lbs., with some variation depending on the materials used in the body and the number and density of the glass elements employed. If you have the opportunity, get a feel for the heft of your spotting scope choices at a local optics retailer. Try them out with different tripod options to get a feel of the total weight you may have to bear during future birding trips.
Often, the best-sized scope for you is the one you are comfortable taking along and not leaving behind due to prohibitive bulk and weight.
Typical mid-sized spotting scopes often have a magnification factor somewhere between about 15- and 60-power, making your subject appear that many times larger, or closer, than the naked eye. Most modern scopes offer a zoom eyepiece that covers some portion of this range with a twist of the wrist and is denoted as the first number(s) that describe its specification. For example, a 15–45 x 65mm spotting scope magnifies by 15x at the low end and 45x at the high end, and everything in between. Some scopes have eyepiece options available with different properties, such as a single fixed power, wide-angle views, long eye relief, a range finder, or binocular eyepiece configurations. Ask your favorite optics professionals about the pros and cons of each of these.
You will find a substantial portion of your viewing will be done at the lower range of your spotting scope’s magnification, where the field of view is bright, steady, sharp, and generally more pleasing to the eye. The wider field of view available at low magnification is also useful for finding and following your subject before zooming in for more detail.
The highest reaches of your magnification range are useful for confirming the ID on that far-away red-throated loon offshore, or under calm and bright conditions at closer distances for highly detailed, frame-filling views of that painted bunting in your backyard. But that higher, top-end magnification often comes with a few penalties. The atmosphere can create distorted images that are seemingly magnified with higher power under certain conditions where air meets water or land of different temperatures, such as over a mudflat or lake. Higher magnification performs best with a large front objective lens, and that can increase the size and weight of your spotting scope, which means more for you to carry. You may need a more robust tripod to control the shakiness inherent with higher magnification as well.
All of these factors come with a real dollars-and-cents price, so keep in mind how much magnification you will really use and weigh these tradeoffs carefully. A 15–45x 65mm scope may be all you need and are willing to carry around birding all day, but higher magnification and a larger scope may provide the digiscoper or videographer with the brightness and magnification for great wildlife portraiture and candid recording of behavior.
Angled vs. Straight
Another decision you must make is whether a straight or angled eyepiece orientation is right for you. While this choice often comes down to personal preference, there are advantages and disadvantages to each. Straight spotting scopes are intuitively easier to point and acquire the subject within your field of view—especially at first for novice scope users. With just a little practice, however, aiming and acquiring your subject with an angled scope quickly becomes second nature. Straight scopes can be useful when looking down, say, into a canyon or valley, but the rotating collar that almost every modern angled spotting scope is equipped with allows you to rotate the eyepiece to a more comfortable position, negating this difference to a fair degree.
Because of the upward 45-degree angle, an angled spotting scope can be kept lower on your tripod, ideally sitting on the “shoulders” of the tripod with the center column all the way down. This can provide a more stable image at high magnification and in windy conditions. As every good birding guide knows, angled scopes can be easier to share with a group. Set your tripod height for the shorter people in the group and everyone can easily bend down and look though the scope without adjusting the scope height and potentially losing the brief shared look at a lifer. Angled scopes are also convenient for looking up in tall trees while keeping the scope relatively low and stable on the tripod.
Both straight and angled spotting scopes can be mounted and used on your car window. The flexibility provided by the rotating scope collar can give an angled scope a wider range of viewing from your window without moving the position of your car. In other words, it’s easier to look further behind or ahead of your vehicle without contorting yourself to get a look through the eyepiece, though it can take some practice aiming your scope at these odd angles.
Finally, straight and angled scopes have different centers of gravity that may or may not be offset by the position of the scope’s mounting foot. Straight scopes tend to be weighted a little farther back toward the eyepiece, which may determine whether you will need a sliding balance rail in order to keep your scope level when the weight of a camera or smartphone is mounted on your eyepiece for photography.
Once your practical considerations about size, weight, magnification, and eyepiece configuration are settled, it’s time to think about the finer details—many of which will affect your overall enjoyment in the field and pertain directly to the quality of optics in your new spotting scope. Regardless of glass quality, increasing magnification with a zoom eyepiece found on most spotting scopes will diminish your field of view as well as the brightness and resolution of your image. The high magnification inherent in spotting scopes really pushes the limits of their optical systems, revealing the particular strengths and weakness of their optical design, the quality of the glass used, and the coatings applied to that glass.
The large glass elements and glass surfaces of a spotting scope require precise manufacturing, placement, and coating throughout the optical path, which is why even the most affordable spotting scopes can seem like a formidable investment.
Thankfully, a spotting scope is a relatively simple instrument without many bells and whistles. That means optics manufacturers do their level best to offer the best optics they can for the price. Variations in build quality, body design, and ergonomics may separate one from another, but spotting scopes within a certain price class tend to perform similarly to the eye. Work within your budget, but find a scope near the top end of it and you will push off that urge to upgrade for years. Find the best scope to your own eye and the one that fits your birding style and feels right for you. And again, if you have the chance, get a look and a handle on several with your local birding or optics shop—or talk with your trusted birding optics experts and friends such as those at Redstart Birding.
Just as patience, careful study, and repetition are necessary to improve your birding abilities, honing your skills with your equipment can help you make the most of the investment in your birding optics. Practice is necessary to master fast and effective locating, scanning, and following of your subjects with a spotting scope. You will have a small field of view at high magnification. Things can seem a bit dim in challenging light, and it can be very shaky compared to your trusty binoculars. Don’t be intimidated. Take some time in your backyard practicing your aim on various targets, be they stationary or moving. Practice zooming in and refocusing at different distances. Start at low power for finding and scanning, then when your target is acquired, zoom in and focus to reveal the details. And don’t feel afraid to look up with your eyes or binoculars when you feel lost.
Lastly, save room in your budget for a quality tripod. There’s nothing worse than spending a bunch on a nice spotting scope and then not being able to take full advantage of the wonderful optics and magnification because it is not adequately supported. Look for the sturdiest tripod you care to bear when combined with the weight of your scope. Choose one that has a sturdy head with smooth pan and tilt motion that capably performs under the weight of your scope. Find one that is tall enough for you. Excessive center column extension can introduce frustrating instability. And finally, if budget allows, a carbon fiber tripod can help you save up to a pound of weight while greatly reducing the vibration that is the bane of high magnification viewing.