Home Camera, lens & related electronics gear Light sends us pictures when we look for wildlife or into a rifle sight. Getting sharp pictures is important if we’re to identify a warbler, distinguish an antler from a branch, or center a bullet. Light coming in through your eye’s protective cornea continues on through
a lens. Images are formed at the rear of the eyeball, on the retina.
Your eye’s lens is controlled by muscles that change its shape. Flattening
the lens or increasing its curvature, these muscles control its focal
length, ensuring a sharp picture however far you’re looking. But not
all lenses are perfect. Did you know…A rifleman today can hit small targets at long range using his Leupold variable scope, a sight marksmen could hardly have envisioned 100 years ago. Scanning a prairie dog pasture with his Leica range-finding binocular; the hunter here will also use powerful glass to aim. For more than 700 years, eye glasses have brought sharp vision to imperfect eyes. The first were con vex lenses, to help with far-sighted- ness. Concave lenses for the near sighted followed. Then, in 1784, Benjamin Franklin came up with bifocals. A century later, contact lenses appeared. Outdoors enthusiasts look through other glass: binoculars, riflescopes and spotting scopes. This guide is about them. But really it is a guide about how smart people have figured out how to manipulate light. Light is central. Without light, the wall across the living room would still be there, but you’d not see it. Without light, there would still be horizons of high rock, but they’d never be photographed. Without light, most of what we think interesting would be suddenly without appeal. We need light to explore, find, recognize, under stand. Even if plants could live with out chlorophyll and we could navigate in the dark, life would be different indeed without light. Small wonder that the Bible warns against an outer darkness and equates God and life with light. It’s easy to get caught up in the mechanisms that change the way we see. But a clever device is of no utility unless it helps us see better. Better vision may mean a higher degree of resolution, or a brighter image. Maybe a bigger image is all you need; then again, you might be better served with the widest field of view. You’ll want true color rendition, a flat field and sharp focus. But how much depth of field are you willing to concede for higher magnification? What will you trade for less critical eye relief? Hew much weight and bulk will you carry to get the optical qualities you want? Choosing glass is often an exercise in compromise. To get the best optics for the job, you need first to define the job, then to specify what’s most important to your eye: What mix of image qualities is better than all others. Did you know… A 6-24x50 Swarovski is typical of the big, high-quality scopes favored by long-range shooters now. The best view isn’t always through glass. Unaided vision is fast and gives you a panoramic view and good depth perception. John Colter would not have escaped the Indians if he’d run with a binocular to his brow. On the other hand, hunters using binoculars commonly find game that they’d miss with the naked eye. A spotting scope can help you tell if that distant bull elk has big antlers or just an average scope would be worthless it you were trying to find a deer while still hunting through a cedar swamp at dusk. The best glass is the glass that best helps you with a specific task; it is not always the most powerful or expensive or sophisticated instrument. Reticles belong in riflescopes, where we need an aiming device. But reticle choice matters. The fine reticle useful for target shooting and varmint hunting is easy to lose in woodland shadows. You may find a lighted reticle helpful in one sight, a rangefinding grid helpful in another. An adjustable objective is useless on a shotgun scope but essential on a benchrest sight. The high magnification of a target scope becomes a liability when you’re trying to aim quickly at a whitetail in overdrive. Best is as best does. Choosing and using field optics would be easier if light were the same all the time. It is not. That is why we have rainbows and sunsets and moon-washed landscapes and all the other delights that make life a constant joy. No optics will give you the warm light of dawn and dusk at midday, or put shadows where shadows are not, or take them away. No field glass will give you clear vision if you look toward the sun or through a blizzard. No lens will give you a motionless picture if the wind is buffeting your arms, or wring the mirage from an image that swims. So we are always reminded that the glass is but a window to light. Outside there is light. Light gives life. And light defines it. Next: Light Prev: Intro (part 1) |
