You don’t NEED the best spotting scope for hunting, but one can be quite helpful. I find one of these 15X to 60X telescopes essential for accurately judging trophy quality. But even when I don’t care about that last inch of antler or horn, a spotter helps me find game as far away as five miles. It’s almost a magic wand for scouting. But only if it has the right stuff. We’ll list and describe what’s right and why in this report.
How to Use Your Best Spotting Scope
Before digging into the technology of spotting scopes, let me give you a quick outline on how I use one. When hunting or scouting I find a high perch looking over suitable game habitat. First I scan for anything obvious with my naked eyes. Then I scan methodically with a binocular, stopping now and then for another naked eye search, just in case something has popped into view close. Then back to the binocular. Once I’ve located a prospective animal, I mark its position with distinctive landmarks like trees, boulders, etc. Then I quickly switch to the spotting scope mounted on a tripod. At its lowest power I “eyeball aim” it toward the spot, find the landmarks, and frame my subject in the center. Only then do I turn up the power to maximize the view, tweaking focus as necessary. Depending on atmospheric conditions I might see detail most clearly at 40X or 30X or, sometimes, 60X.
If I find no game, I’ll begin studying more distant terrain and habitat. I can take in great sweeps of country at 20X or higher. Over the years friends, guides, and I have found game miles away. We’ve identified many as worth the hike from that far, too. Master sheep guide Lance Kronberger once determined via a 60X Nikon scope that a Dall’s ram roughly five miles away was full curl. At those distances it takes crisp, clean air plus a lot of watching and studying to determine horn and antler size, but this sure beats climbing several thousand feet and hiking three to ten miles on a hope and a prayer.
A good spotting scope will be effective until perhaps 30 minutes after sunset — unless you focus it on Jupiter, Saturn, the moon, and other celestial bodies. Then it’s good all night. At 60X you can see Saturn’s rings, Jupiter’s Great Red Spot, and often its four Galilean moons. But you’re probably more interested in rings around ram horns and tines on antlers, so let’s next look into what makes a spotting scope effective for viewing terrestrial objects.
As you know, the best spotting scopes are expensive. You don’t want to waste your money on useless features, so it pays to understand what contributes to stellar performance. Think of a spotting scope as one barrel of a binocular, but with much higher magnification. This means most ingredients in a good binocular are needed in a good spotting scope, too, with just a couple of twists we’ll describe below.
Best Spotting Scope Ingredients
First, you want a large objective lens on a spotter because, like binoculars and rifle scopes, the objective diameter divided by power gives you the Exit Pupil, that little circle of light you can see in an eyepiece held at arm’s length. This must match the diameter of your own pupil to maximize light reaching your retina. If EP is smaller than your pupil, the image appears dimmer. If EP is larger than your eye, the excess rim of light just bounces off your iris and you gain nothing except more leeway for shifting your eye side-to-side and back-and-forth behind the eyepiece before you see edge blackout. Which is no small thing.
Exit pupil diameter in spotting scopes changes with the power of the zoom eyepiece. At 20X, a 60mm objective lens would yield a 3mm EP. That’s not an overly large EP. In full daylight the human pupil shrinks to about 2.5mm, so a 3mm EP will provide all the brightness your eye can possibly take in. But dial the power up to 30X and EP shrinks down to 2mm. Now you’re seeing things a trifle dimmer than they really are, but still easy enough to see. At 60X, however, EP is just 1mm. Quite a dark image, but, amazingly, you can still see it with remarkable detail.
To get a brighter view, you can step up to an 80mm objective. At 20X it will give you a 4mm EP. At 40X it will be down to 2mm. But at 60X it’s just a 1.33mm. There are some spotters with 90mm and 100mm objectives. That seems like a big deal and it sort of is, but 95mm divided by 60X still leaves you with a less than 1.6mm EP.
Brightening Those Small Exit Pupils
Does this mean you’re condemned to looking through a glass darkly? Not if you get the rest of the spotting scope’s features right. Remember the anti-reflection coatings that maximize light transmission through a binocular? Same thing applies to a spotting scope. You want a spotting scope with all air-to-glass lens surfaces multi-coated. This is usually advertised as “fully multi-coated.” These coatings maximize light “throughput” via destructive interference wave cancellation easier appreciated than explained.
ED Glass Essential in Best Spotting Scope
In addition to these coatings, your spotting scope should include an ED (Extra Low Dispersion) or HD (High Definition) lens made of fluorite crystals. ED and HD are marketing terms without specific definitions, so make sure they actually reference a fluorite lens because such a lens is critical for minimizing color fringing. Color fringing rears its fuzzy head as a halo of purple, yellow, or red color around the fringes of objects, especially those contrasting strongly with the background like elk antlers against the sky. Color fringing becomes distracting at about 20X and grows worse with any increase in magnification. Nip it in the bud with ED glass.
Most, if not all, spotting scopes use a Porro prism to correct the upside down and backward image projected through the objective lens. The Porro prism is positioned in the bend or bump in front of the eyepiece. It is better than a roof prism because Porros do not require a reflecting mirror, which always loses some light. A Porro does not require phase coating nor more expensive BaK4 glass for maximum resolution, either. Its only drawback in a telescope is that bulky bend or bulge in the tube.
These, then, are the “parts” that make a spotting scope sharp and bright: fully multi-coated lenses, large objective lens, and ED (fluorite) glass. You can shop for external lens coatings that minimize scratching and resist water and oils for convenience and increased durability, too. Most brands add these just to remain competitive. The impressive thing about a high-quality spotting scope with all these ingredients is how well you can see at low light through even small EP diameters. I’m usually using my spotting scope well after sunset and well before sunrise.
Choose An Angle on Convenience
Another important consideration is the angle of the eyepiece. It can be straight or angled about 45-degrees. Straight is easier to aim at the subject accurately and more comfortable to use from a car window mount. A straight eyepiece is easier to use with a camera for digi-scoping, too. An angled eyepiece takes some getting used to because you look 45-degrees away from your subject. But once you have it locked in, you can sit or stand with your head/neck in a comfortable position looking down into the view. And if someone else wants to see, you don’t have to get up. Just loosen the rotating barrel collar (a wonderful convenience with an angled viewfinder) and spin the eyepiece to the side where your partner can get the view. The scope’s axis remains on target. If you want to get really sneaky, poke the scope over a boulder or some brush, lie down and look up into the angled eyepiece. You can watch a bedded deer for hours like this.
You may notice that some scopes focus via a collar on the barrel, others with a small knob projecting above the main barrel just in front of the Porro prism housing. Many find the latter type easier to tweak precisely without moving the scope’s position. Try a few to see what you like.
How to Compromise Size and Weight
Bulk and weight will be an issue in the field. It’s always a compromise. The more you climb and hike, the less bulk and weight you want. But when you need to sort out an elk herd a mile away at dusk, you want the biggest objective you can get. Spotters come with objective diameters from 50mm to 100mm. Most of us settle for the 80- to 85mm compromise. Anyone glassing from or near a vehicle might want the 95- 100mm objective. Serious backpack hunters usually go with the 60- to 65mm objectives.
Pay some attention to little things like sunshades/lens hoods. Those that are integral and pull or twist out are best because you won’t lose them. Eyepiece caps are problematic. Most slip on and off too easily. I wish more came with a clamp-on or screw on cap. An acceptable option is a complete neoprene jacket. These protect against bumps and scratches as well as dust and rain, although most good scopes are guaranteed dust and waterproof. I don’t like the bulk of neoprene jackets flapping in the wind or the time required to open them, but the hassle may be worth it.
Finally, you’ll need a solid tripod that adjusts to a comfortable standing height. You can get by with a kneeling/sitting height, but sometimes you don’t want to sit on the cold ground and sometimes you have brush you can’t see over. Bean bags work well on vehicle hoods and windows.
I truly enjoy using binoculars and spotting scopes when scouting and hunting. They not only help me find more game, but let me see things I wouldn’t otherwise see — like the red fox and golden eagle sparring over a dead carcass on the far side of the mountain valley. And that raft of bluebills bobbing off a distant point. And a beard hanging off the breast of a turkey silhouetted in a cottonwood tree at dusk. And the license plate of a vehicle trespassing on my neighbor’s bean field. And…
Features of Best Spotting Scopes
- Fully multi-coated lenses
- Large objective lens
- Fluorite glass (ED or HD)
- Zoom eyepiece
- Rotating collar (with angled eyepiece or camera attached)
- Integral hood
- Scratch and oil resistant exterior lens coatings
- Rubber armor exterior
- Straight or angled eyepiece (your choice)
- Water, fog, dust-proof guarantee
Ron Spomer’s eyes were opened to the value of a spotting scope when his brother bought a little Bushnell Trophy in the early 1970s. He’s since enjoyed the views through Swarovski, Leica, Meopta, Sig Sauer, Leupold, Nikon, Vortex, Pentax, Celestron, Zeiss, and additional Bushnell scopes.