Choosing the right scope can be difficult, and the technological improvements in recent years—though certainly beneficial—can be confusing if you’re just getting familiar with shooting. Light management, mechanical reliability, ruggedness, cosmetics, clarity, and value have improved dramatically, turning many riflescopes into high-tech optics that sportsmen and women could only dream of thirty years ago.
When shopping for a riflescope, it’s essential to compare construction, mechanical reliability, optical qualities, ability to reduce glare and handle light, and overall suitability to your hunting application. And never underestimate the value of a world class warranty and good customer service.
In 1947, Leupold introduced the first nitrogen-filled riflescope. This was a response to the problem of fogging, which had plagued many scopes up until that time. Scopes had been a mostly fair-weather proposition, and they could never really be depended on in the field. Leupold & Stevens created a new industry standard for environmental protection in riflescopes by purging the scope’s oxygen and filling it with nitrogen. Problem solved.
Today, virtually every scope manufactured claims some degree of fogproof construction, and this is very critical to the overall performance of the scope. Absolute waterproof integrity and durable construction are especially critical for hunters and shooters in extreme conditions. Rapid temperature changes, humidity fluctuations, and even variations in elevation—the hallmarks of extreme hunting—can compromise the waterproof integrity of a scope.
A scope’s optical quality is just as important as its ruggedness. Lens glass is carefully chosen based on its function within the scope and its ability to meet the optical requirements specified by optical engineers. Glass is carefully cut and polished to remove any scratches or inclusions that could interfere with the clean passage of light through the lens. Special multicoatings (layers of metallic compounds that increase light transmission) are applied to maximize light transference and clarity. The result is unsurpassed clarity and brightness, even when conditions are far from ideal. Today it is much easier to spot the difference between a tan game coat and brown underbrush than it was even a generation ago.
Of course, lenses are only part of the optical equation. Glare is the enemy of light management, and it’s a difficult element to master. Extensive internal blackening of components, (including lens edges in some cutting-edge riflescopes), coupled with intensive grooving of the inside of the scope tube itself, causes light to be channeled properly through the scope. These treatments reduce the incidence of stray light bouncing around within the scope body to ruin image quality.
Modern riflescopes should deliver crisp, accurate windage and elevation adjustments and a reliable point of impact across the entire power range. In years past, variable riflescopes often shifted point of impact as easily as they changed magnification. This is no longer the case, and now most variables will deliver the same point of impact when set at 3.5x as they will when set at 10x.
Variable-power scopes also offer a light management advantage over fixed power scopes. As you change magnification, you also change the exit pupil, a measure of the light passing through the scope to your eye. Exit pupil is derived by dividing the diameter of the objective lens by the magnification of the optical device. The human eye can dilate from about 7mm for a young person in total darkness to 2mm in bright sunlight. Ideally, the exit pupil of the scope should match or slightly exceed the dilation of the eye’s pupil so that the eye receives as much light as possible.
An example of exit pupil: if a hunter goes out with a 3.5-10x40mm scope early in the morning, he can dial his scope down to 5x, and he will receive an 8mm exit pupil (40mm divided by 5x equals 8mm exit pupil). Later, when the sun is high and bright, he can turn his scope up to 10x and still receive a 4mm exit pupil (40mm divided by 10x equals a 4mm exit pupil), which is excellent for bright conditions. As evening approaches, he can turn the scope back down to 8x or so to receive a 5mm exit pupil (40mm divided by 8x equals a 5mm exit pupil) and still have plenty of light to make a shot at the end of legal shooting hours.
Obviously, exit pupil depends on magnification and objective lens diameter. If magnification is increased, exit pupil will decrease, unless the objective lens diameter increases proportionally. 50mm-objective riflescopes will deliver a larger exit pupil and a brighter image in poor light than a similarly powered scope with a smaller objective. Of course, there are tradeoffs with a 50mm scope: higher mounting, greater weight and bulk, and a higher line of sight in relation to the bore line. All of these factors must be considered when deciding on a scope for your style of shooting. In most cases, a scope that delivers a 3.5-5mm exit pupil at a comfortable magnification will be more than adequate for most hunts.
Something else to remember is that contrary to common belief, a larger objective lens does not increase the field of view of a riflescope. It only increases the amount of light entering the scope, and, in the case of scopes using slightly less capable components, it will increase the “sweet spot” at the optical center of the lens, making images appear sharper and more crisp in the center of the field of view.
Field of view, magnification, and eye relief are the three elements of the “optical triangle,” and they all work together to give a hunter the pleasing, full view that he needs. Heavy timber or close-range shooting demands a large field of view, which is dependent on lower magnification. So an elk hunter or coastal deer hunter might prefer a 2-7 variable, with the ability to set the magnification on 2x for up close and personal shooting, and still increase the magnification to 7x if a 200 yard shot across a clearcut presents itself.
On the other hand, a hunter pursuing sheep or pronghorns may prefer a 4.5-14, since he is more likely to take a long-range shot where magnification will help make a quick, clean killshot.
Varmint hunting demands higher magnification, as shots are usually very long and targets are very small. Because most varmint rifles don’t recoil much, eye relief can be sacrificed for magnification. Eye relief of 3.5 inches or more is ideal for these rifles, and four inches is even better. This will deliver a full picture and keep the objective lens out of a shooter’s eyebrow during recoil.
Flexible reticles, such as the Duplex ® invented by Leupold over 40 years ago, lead the shooter’s eye naturally to the center of the aiming point and are ideal at close range or in heavy cover. Lighter or finer variations of the same reticle provide good range estimation and also procide the fine aiming point needed for longer range.
Reticles have continued to develop into the more complex (yet extremely capable) range-estimating reticles we see today. Some examples include reticles designed for tactical applications, such as the Mildot, Horus Vision reticle, and some of the reticles employed by Nightforce. Each of these reticles provides many aiming points, or a grid to make very long range hits easier. For the hunter, reticles such as the Ballistic Plex, Boone & Crockett Big Game reticle, Varmint Hunters Reticle, or TDS reticle all provide simpler, yet very effective methods of making hits at the longest ethical ranges. Though, as with any worthwhile pursuit, practice makes perfect.
Many of today’s riflescopes use 30mm maintubes. The 30mm tube provides more strength and often more windage and elevation adjustment. This makes it easier to get zeroed at the range, and for those shooters who love to shoot long distance, it allows you to “dial up” to be on target at longer ranges.
Finally, never forsake a good warranty. Of course, the best warranty is one you never have to use, but in the rare instance that a scope does go south, it is good to be covered by product service that is fast, reliable, friendly, and free. Leupold scopes are designed, machined and assembled in America, and they come with the Golden Ring Guarantee. If your scope doesn’t do what it’s supposed to, we’ll do everything we can to make it right. Our Tactical scopes don’t have the Golden Ring for obvious reasons, but the Guarantee remains the same.
Webpage Updated: Jan.2017