This is the fifth in a monthly series of articles written for Opticstalk.com by John Barsness (www.riflesandrecipes.com)
A spotting scope’s use in hunting often begins before the season actually opens. A spotting scope allows the hunter to “scout” big game animals without disturbing them. This works not just in the wide-open West but anywhere some distance can be found, whether across a Midwestern farm field or from ridge to ridge in the
Americans hunt deer more than any other big game, and a spotting scope is particularly useful when scouting for either mule deer or whitetails in late summer before they shed the velvet on their new antlers. At this time of year the antlers are soft and tender, and even big whitetail bucks will spend more time in the open. Also, the coats of summer deer are reddish, so they stand out at long distances.
Bucks also tend to hang out together before their antlers harden. They’re not producing as much testosterone as they will later in the fall, so are a lot more mellow around their potential rivals. During the last days of August I’ve seen as many as 14 branch-antlered whitetail bucks in one small field, and as many as six mule deer bucks bedded on a mountainside. In the West you’ll often see several bull elk together, and in the
These bachelor herds break up during the rut, but their members will still be somewhere around. Whitetails, especially, tend to stay in the same general area. Mule deer and moose may wander further, but will generally be within a mile or two of their late-summer hangouts. Elk will wander the farthest.
One thing quickly discovered during such scouting is that really high-powered spotting scopes aren’t quite as useful as many hunters would imagine. Two things interfere with a clear view when a scope is cranked much above 40x: a small exit pupil and heat waves.
The first is most important during dawn and dusk, when game animals are most active. A 2mm exit pupil is marginal but OK in dim light; anything less results in a view with almost no contrast and detail. A spotting scope with a 60mm objective has a 1.5mm exit pupil at 40x. Crank the same scope up to 60x and the exit pupil shrinks to 1mm. This just doesn’t get it done in anything except bright sunlight, the reason that serious hunters often invest in yet another spotting scope with a 75-80mm objective lens. These can be cranked up to 40x and still have an exit pupil of 2mm.
The other problem occurs as the sun rises higher, when heat waves begin to rise as well. The image may be bright at 60x, but you won’t be able to see much detail because heat waves interfere. On the high plains in early autumn I’ve seen heat waves interfere so much with the view that by 9:00 in the morning that it’s impossible to see horns on any pronghorn much more than half a mile away. You can tell that their head is black, both because of the black horns and the dark throat patch, but you can’t actually see the horns.
This is why most of my hunting scopes have eyepieces that don’t go above 40x or 45x. There’s just too little practical use for higher magnifications. However, if you like to use a spotting scope for, say, star gazing, then higher magnifications can be useful. At night there’s no problem with heat waves, both because of cooler temperatures and because the scope is pointed upward, away from heat rising from the ground. It’s pretty cool to be able to see the moons of Jupiter or the rings of Saturn.
Some spotting scope purists insist on fixed-magnification eyepieces, since these usually provide a slightly sharper view than variable eyepieces. This may be true in an absolute sense, but hunting involves a wide range of light and terrain. You’ll actually be able to see much better with a slightly less-sharp variable eyepiece, because the magnification can be “tuned” to the light and atmospheric conditions.
Something in the 12-40x or 15-45x range is just about perfect, partly because the lowest magnification provides a wide field of view. When hunting, spotting scopes are often used along with a binocular. The game is often spotted with the binocular, and then the scope is used to zoom in for a better view, allowing us to evaluate the animal itself and, sometimes, details in the terrain in preparation for a stalk.
It also saves us time and effort. Both are often at a premium. A spotting scope allows us to get a good look at the horns or antlers of animal before making a long cross-canyon hike. This isn’t only a matter of trophy evaluation, but often of making sure the animal is legal. Many areas require a certain number of tines for antlered game to be legal, and in at least parts of