The Straight Scope: On Riflescopes

Very few items generate more noise than the shrill, subjective, unscientific, statistically meaningless banter surrounding scopes. It isn't helped much by printed scope "tests" that compare 32mm objective scopes to 50mm objective scopes, 2-6 power scopes to 4.5-14 power scopes, $200 to $1500 scopes, and then end up giving a tortured "Best of Test" award to a scope that has never, ever been compared to anything remotely similar in terms of objective size, price, power range, or intended use.
All too often, a scope that has never actually been compared to anything in its class is declared a "winner." It is easy to win a race on an empty track. There are several myths about scopes that are easily disproved. If you are open-minded enough to take a fresh view, you might find a few of them to be of interest.

I. "You Get What You Pay For"
The consumer pays for everything, and the scope industry is not immune from this. The consumer pays for high or low labor rates, high or low marketing campaigns, high or low production efficiency, packaging, distribution, employee benefits, distributor profit, sales rep profit, and dealer profit. The consumer also pays for high or low incoming freight and customs fees. None of these items has anything exactly correlating to the quality of the product. Pay all you wish for glossy ad copy, expensive sponsorships, import duty, or expensive labor rates. The scope that is associated with that will automatically be no better or worse for it.

II. We DON'T Want the Brightest Scope
We might think we do, we might say we do, but we really don't want the brightest scopes. The rules of optic do not change just because we call a telescope a riflescope. To get the brightest, clearest scope possible we need huge objective lenses, for it is the objective lens that ultimately controls resolution and potential light transmission. You might think there would be a market for 60mm or 70mm hunting scopes, but it appears that there isn't. Yet, doubling the size of an objective lens quadruples its light gathering ability.

Even a 50mm objective transmits 55% or so more light than a 40mm objective. Who but the most brainless of us could not want a “technically superior” objective like that? Most of us don't, and for good reasons.

You will get better strength, lower cost, less weight, less parallax, and greater depth of field with the 40mm objective. Human eyes are not the best on the planet; much technical light transmission cannot be detected, much less used, by the human eye. Most of us do not want our scopes mounted as far away from the barrel as possible. Necessarily, larger objectives prohibit close scope to bore mounting. Human eyes quickly lose the ability to distinguish color as the light fades; the human eye's deficiencies pretty much negate the theoretical advantages of large objective lenses.

Who can say that, under hunting conditions, they can hold a 12X scope steady enough in the off-hand position to be usable? How about with a 20 mph crosswind? I normally can not. We may think we want the brightest scope in the barn, but human eyes do not have the ability to use much more than a 5mm exit pupil. Just like binoculars, which are a pair of telescopes mounted together, reasonably large objectives and low magnifications give us the best images. We rarely seek 60mm or 70mm objective binoculars, either, though recoil resistance and rifle mounting are no longer factors in our choice.

We do not want the brightest and clearest, really, because what mathematics can document our eyes simply cannot take advantage of. Brightest and clearest becomes meaningless because our eyes simply cannot take advantage of the theoretical advantage. I'll finish on "bright and clear" by quoting Scott Powers, who has discussed sniper scopes in detail:

"Objective size. What is reasonable, usable, or just plain hoaky? I will offer my opinion; one I am sure will garnish some argument. I do not believe there is any use for anything larger than 40mm, or 42mm at the most. In a good quality scope, one in fact going to be used for sniping, competition, or collecting, a large objective bell is only a hindrance, no matter what the current hype."

"Consider first the major disadvantage to a 50mm or larger bell. These large objectives force the shooter's head up so high that, on an unmodified stock, he can get no reasonable or repeatable cheek weld. Think of firing an AR15A2 with a scope. You just about have to use your chin on top of the stock to see through the scope. Until you mount a high-rise cheek piece, you will never be consistent. This is not acceptable on a sniper rifle or, for that matter, any firearm used for hunting."

"Your best accuracy is going to be found by mounting the scope as low as possible to the axis of the bore. Why start off on the wrong foot by building in an inherent disability into your weapon system? For more clarity, you say? HA! This is where the industry really loses me. Many companies offer very large objectives claiming that they will transmit more light, be brighter, and cause less eyestrain. All of this may be true, but your eye can only accept so much light. About four to seven millimeters at the exit pupil. A good quality scope with a smaller objective is already capable of this, so why pay for something you cannot actually use? Also, consider that most of these 50mm (and larger) designs came about to assist European hunters who shoot at night. If you are not a poacher, why would you need whatever extra light gathering ability these behemoths might offer? If you are a police officer, chances are that the situation you are in is going to be well lighted by klieg lights, idiotic reporters, or ambient street light. You may even have night vision of one sort or another, depending upon your department's policy."

"If you are a civilian, and a hunter, there are many scopes on the market that offer excellent low-light clarity with less than 40mm lenses. This is another advantage to low power. The lower the power, the more light is transmitted. A small 1.5-5x 32mm will transmit more light than a 10x 50mm. So the question begs: Why spend all your money on objective size, when quality of glass is far more important?"

III. Fairly Recent Scope History
Variable power riflescopes were not developed until the late 1940s, waterproof scopes did not appear until 1960, and fully multi-coated lenses were not in consumer production until the early 1970s. The 90% standard for light transmission for quality riflescopes was not established until that time, the early 1970s.
Even today, many of the scopes in use do not have fully multi-coated lenses, something with no negatives, but it has yet to become a defacto standard for hunting scopes. The media battle over who has the best coatings continues. Fully multi-coated rules the roost if you want 90% light transmission or better, with one exception that I can think of. That is the RainGuard patented by Bushnell that significantly increases light entering the scope over objective multi-coating alone. But not all RainGuard scopes have multi-coated internal lenses. (Elite 4200 scopes are fully multi-coated.) Consumers apparently do not universally care enough to pay for full multi-coating, despite its demonstrable advantages in reducing glare, lens flare, and increasing light transmission.

IV. Eye Relief Hoo-Ha
Certainly, we need adequate eye relief. Very few rifles move rearward more than a grand total of one half of one inch during the entire recoil pulse, recoil pad collapse excluded. Unless you are a stock crawler, or shooting .338 Win. Mag. rounds, three inches of eye relief should be adequate, and anything more than that is generous for all but the most abusive recoiling rifles. Particularly with muzzleloaders (as we are reloaders by nature) an invasively recoiling load is of our own construction, no one else's.
One thing I have found accurate is scope manufacturer's stated eye relief. If we purchase a scope with inadequate eye relief, or eye relief not to our personal whims, it is our own fault. Allowable mounting distances and scope dimensions are all readily available as well. If our scope doesn't fit, we failed to do minimal, very basic, due diligence research. These specifications are available online from all manufacturers at the push of a button.
V. What of Adjustable Objectives?
With the exception of air rifles, varmint rifles, and small game applications, adjustable objectives (AO) serve great particular purpose on hunting scopes. Certainly they add little benefit to a big game riflescope. AO does add length, weight, bulk, complexity, and cost. And just because the dial tells you your scope is "parallax free" does not mean it really is.
Parallax is not readily noticeable until you hit 8X magnification or so, far more magnification than you need at even 300 yards on a big game animal. You may not be able to mount the scope as low as you wish with an adjustable objective, flip up caps can be hard to use, and the last thing hunters should be thinking about with fur in their cross-hairs is tinkering with an adjustable objective setting. An AO might be handy as a focusing tool at the range, but in the field it is hardly a vital feature.
An adjustable objective is a focusing tool; the "side focus" moniker on some newer scopes speaks to that. At least the side focus models are less cumbersome.
VI. Internal Adjustment Range
Often overlooked is the amount of internal adjustment available. With loopy trajectories and hard to mount rifles, coupled with an infinite variety of load combinations, inline muzzleloaders can gobble up internal adjustment range in a hurry. The same can be true for many centerfire rifles, particularly if the scope rail is not mounted dead straight.
An easy scope to sight in with almost any rifle is the Sightron SII 3-9 x 42mm with 95 inches of adjustment @ 100 yards, and 3.6 inches of minimum eye relief. The vintage Bushnell Elite 3200 3-10 x 40mm scope has 85 inches of adjustment @ 100 yards, and 3.7 inches minimum eye relief. Sixty inches or less of adjustment may be problematic on an inline muzzleloader.
How does your scope compare to these two choices? It is wise to know this, and before you buy is a bit timelier than after.

VII. Country of Origin
How many folks have seen a scope assembly line in operation? There is no basis extant to automatically assume that quality of assembly of a scope is better (or worse) based on the nation in which a scope is assembled. It does not hold true in electronics, cars, cameras, video equipment, or computers. Quality of assembly is important, of course, but the geography where that assembly takes place is a meaningless myth, particularly today. The old stereotypes are just getting older.

VIII. Warranty
Most scopes come with "limited lifetime" warranties. Like anything mechanical and man-made, scopes can fail. If that were not so, no warranties against defects in materials and workmanship would be necessary, as there would be none to warrant against. Scopes are not designed to last forever; warranty cost is paid for by the consumer in the initial purchase price of the product.
Leupold started the lifetime warranty as an effective marketing tool, delivered on their promise, and were very successful. Most manufacturers have followed suit, or pretend to.
However, the idea is fundamentally wrong-headed and costs consumers money. After all, a "defect" does not suddenly rear its ugly head 20 years after a scope is put into service. It is normal wear, and the cost of this irrational "lifetime" repair of non-defective product must end up where all other costs go--into the cost of new product.
The automobile industry has learned a costly lesson in this connection, with GM and Ford now at 3 years or 36,000 mile standard warranties. Yet a four year warranty on a $250 scope might be viewed as deficient. It is apparently palatable on a $76,000 MSRP Cadillac XLR: 4 years or 50,000 miles against defects, but not on a $250 riflescope.

Finally
The basics of hunting scope use have not changed much over the last several decades. There are more choices than ever before, and that's a good thing. The wise consumer does a reasonable amount of homework, and knows what he wants out of a scope before the purchase. Those still susceptible to what the guy behind the counter has to say (usually based primarily on profit margin and store stock levels), the ink that sticks to ad copy, or blind nameplate loyalty pay a nice premium for their belief. The better choices ten years ago are not automatically the best choices today, and the most reasonably priced product is not necessarily the best long-term investment.

Copyright 2005, 2011 by Randy Wakeman. All Rights Reserved.

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