Telephoto Lenses — Taking the Long View
By Tamia Nelson
September 4, 2012
Clever folks have been trying to improve on the human eye for quite a while now. And since the first reading glasses made their appearance in the late Middle Ages, these innovators have been tinkering with lenses. The subsequent invention of the telescope catalyzed a revolution in astronomy — though it also got one early adopter, a certain Galileo Galilei, into a fair amount of hot water with the pope. But it's hard to put a lid on technological innovation, even for a pope, especially when the technology in question has military applications, and this was as true in the 17th century as it is today. So the telescope is still with us.
In fact, most paddlers always have one or two of these handy gadgets in their packs. Lots of us wouldn't leave home without our binoculars, after all, and what is a binocular but a pair of conjoined telescopes? Of course, not everyone is as taken with binoculars as I am. Some notable paddlers, R.M. Patterson of Dangerous River fame among them, have preferred monoculars — those compact descendants of the ancient mariner's spyglass. And Farwell, when he's in high ironical mood, likes to point out that one of the unsung advantages in being half‑blind is the weight you can save by replacing your heavy binoculars with this lighter alternative. But he still keeps his old pair of Zeiss 10 x 40s in a case on his desk.
As useful as binoculars are to paddlers and other backcountry explorers, however, photography is the place where the telescope really makes its mark. Few paddling shutterbugs would be happy with only a normal lens. (What's a "normal" lens? For a digital single‑lens reflex with an APS‑C sensor, it's any lens with a focal length of 35 mm or thereabouts — or around 50–55 mm for a 35 mm film camera.) Don't get me wrong. Normal lenses yield an image whose field of view and apparent perspective approximate those of the unaided human eye. As such, they're perfectly OK for shots of the gang around the campfire and most sunset scenics. A time will come, though, when you want to do more. Maybe you'd like to bring a momma grizzly up close without becoming part of her picnic lunch. Or capture the smile on your buddy's face as he negotiates a tricky mid‑river drop. Or grab a close‑up of a soaring eagle that looked no bigger than the tip of your little finger when you first caught sight of him.
In such situations, your normal lens just won't hack it. But that's not a problem. Simply unlimber …
A Longer Lens
That's longer as in longer focal length, by the way, though telephoto lenses are almost always longer in body, as well. Chances are you already have one of these long lenses, too, since most point‑and‑shoot cameras come with zoom lenses that offer a limited telephoto capability. In any case, if you don't own a telephoto lens now, you probably will soon. After a casual shutterbug acquires a single‑lens reflex camera and starts to think of himself as a serious photographer, the first auxiliary lens he buys is often a telephoto zoom. Why? Well, I've already hinted at several of the reasons, but let's see some examples of telephoto lenses in action, shall we? That should answer the question. And here are a few typical shots, beginning with several photos of paddlers doing battle with one of the livelier stretches of The River, …
Followed by a handful of candids showing how river life is lived in its less frenetic moments:
Of course, these shots only hint at the range of possibilities. If you're so moved, you can follow in Galileo's footsteps and check out our nearest celestial neighbor, both as a subject in her own right and as an element in more down‑to‑earth compositions, …
Or you can turn your far‑seeing lens on nearby subjects, and see familiar features of the landscape in an altogether new — and sometimes strikingly attractive — light:
And why stop there? It may seem like a contradiction in terms, but a telephoto lens is also an ideal instrument for bringing the invisible world at your feet close enough to see, though for this you'll need either a lens with a built‑in macro capability or a clamp‑on macro converter:
Have I awakened your interest? I hope so. Now let's take a closer look at the hardware itself. To begin with, it helps to understand exactly what a telephoto lens is, and what it can do to bring distant subjects nearer. The photos below should help. Each was shot at the indicated focal length. I resized the resulting images to permit easy side‑by‑side comparison, but I didn't crop them. In other words, what you see in each shot is the entirety of the field of view. And all were taken from the same place, about 10 feet from my ever‑obliging, infinitely patient model.
Are you experiencing a déjà vu moment? Then you must be a regular reader, because I used the same photo gallery in my earlier article about wide‑angle lenses. Here's a relevant quote from that column:
The shot labeled "35 mm" comes closest to the perspective of the 50-55 mm "normal" lens on the once-ubiquitous 35 mm film camera. In other words, a 35 mm lens is the new normal — for my digital SLR and for many others that use the APS=C sensor. And the extremes? Well, the 300 mm lens on my camera corresponds to a 450 mm "super-telephoto" on my old film camera, while the 10 mm wide-angle is best described as "ultra wide-angle," equivalent to a 15 mm lens on a 35 mm camera.
Where, then, does the borderline between normal and telephoto lie? I'd put it at around 55 mm for a digital single‑lens reflex with an APS‑C sensor, or somewhere near 80 mm for a 35 mm film camera. That's a "short" telephoto, by the way — good for portraits, some landscapes, and large animals. (If those large animals aren't too far away, that is. But do you really want to get close to a large animal of uncertain temperament? I don't.) Birders and others will want much longer lenses: no less than 200 mm for a digital single&8209;lens reflex. Longer really is better here, however, and a 300 mm lens probably strikes the best balance between reach, weight, and cost, at least for most paddlers.
OK. You've got your telephoto. But that's just the first step. Now you'll want to learn …
How to Get the Most From That Long Lens
No lens does everything well, and telephoto lenses are no exception. We've talked about what they can do, and it all adds up to an impressive bag of tricks, but now it's high time we took a more critical look. The devil, as the old chestnut goes, is always in the details.
Bigger is better, right? Er… No. It's not. Not always, at any rate. While most paddlers will want a longish lens, telephoto lenses are heavier and bulkier than their normal counterparts. And they stick out further, too. Which means it's easy to bang into things with them. This doesn't do the lens any good. Storage can be a bear, as well, especially for really long lenses that require custom waterproof cases. Luckily, lenses in the 200–300 mm range achieve that rarest of virtues: a happy compromise. The Pentax 55–300 mm zoom on my K200D (that's the lens in the picture at the head of this column) is a gem, long enough for serious wildlife photography, yet still easy to carry and store.
Why are my shots so blurry? It doesn't do you any good to grab a big image if that image is fuzzy. And telephoto shots often are. For one thing, the extra weight and bulk of the long lenses make it harder to hold your camera steady. But the real killer is the magnification itself. When blown up by a telephoto lens, little tremors look like big shakes. I've talked about some remedies for this in earlier articles. A firm grip, a solid stance, and easy, regular breathing can do a lot to quiet things down. A lot, perhaps, but maybe not enough. For shots at high magnification and slow shutter speed, you'll need a tripod or monopod, and that's one more thing to carry and look after. The results will be worth it, though. Trust me.
That's funny. I didn't think it was so dark. A lens can only let in as much light as its "window," or maximum aperture, permits. Bright lenses have big apertures. Unfortunately, inexpensive telephotos run to small apertures. (And the expensive telephotos run to very high price tags.) The upshot? You need to watch the light and make the most of whatever illumination is available. Start by increasing your camera's ISO — 400 is a good place to begin, though higher is better. (Warning! Many digital single‑lens reflex cameras yield grainy shots at high ISOs. Things are getting better, however.) Longer exposures help, too. But be sure to use a tripod.
How come Fred isn't in the shot? In photography, as in most of life, free lunches are rare. A telephoto brings distant objects closer. You pay a price for this, however. As the magnification increases, the field of view gets smaller. So pay careful attention to how you frame your shots. The good news? Sometimes small is beautiful: A "tight" shot can concentrate the viewer's eye on your subject. This is a very good thing in many types of action shots, not to mention portrait and wildlife photography. Need convincing? Then take a close look at this photo:
Care to guess what my subject was? Time's up. It was the solitary crow parading on the rotting ice. Did you have trouble finding him? Me, too, and not only because of the heat shimmer. I'd have gotten a far better result with a longer lens, yielding a (much) tighter shot.
Get back! Get back! Telephoto lenses are like aging paddlers: They have trouble seeing things that are too close. The name tells you why. "Telephoto" and "telescope" share a common prefix, and that prefix means "far away." So if you see a great horned owl perched just five feet over your head in camp, and if you have only a telephoto lens, you're out of luck. Try as you might, you won't be able to bag your bird. Even versatile zoom telephotos like my 55–300 mm can't focus closer than 10 feet or so. What can you do about this? Well, you can buy a telephoto with a macro capability. Or you can fit a macro converter to your lens — but probably not before your bird has flown. Or you can simply reconcile yourself to missing some shots.
There's no depth to 'em! Telephoto lenses aren't the best bet if you want to keep the background in focus. While you can increase depth of field by reducing ("stopping down") aperture, no amount of tinkering will give a telephoto the depth of field enjoyed by lenses with shorter focal lengths. The best strategy? Exploit this drawback to your advantage. As was the case with a narrow field of view, shallow depth of field forces the viewer to concentrate on your subject. If the background of a shot is "busy," or distracting in some other way, this can be a very good thing. For example, in this photo of a chipmunk …
The clutter of shrubs in the background is barely evident. And the portrait of the chipmunk is much improved as a result. (By the way, the same trick works with people.)
There's no depth to 'em, redux. In addition to their comparatively shallow depth of field, telephoto lenses tend to compress long vistas, making them look flat. This is known as the telephoto effect, and it's not always a drawback. In fact, it can be used for dramatic purposes, emphasizing the multiple drops in a staircase falls, the many bends in a wavering trail, or the contrast between the sunlit foreground and a shadowy far shore.
So… How about it? Can you understand why many former shutterbugs mark the start of their apprenticeship as serious photographers from the day they bought their first telephoto lens? I'll bet you can. And now it's your turn.
The woods and waters offer paddling shutterbugs plenty of opportunities, but a lot of subjects are just too far away to capture with a camera's normal lens. Are the loon and her chick that kept you entranced on the lake this summer reduced to mere specks in a vast expanse of blue water? They are? And can you see the grim determination on your buddy's face as he lines up for that last, big drop? No? Then you need a telephoto lens — and now you're well on your way to understanding just how to get the most out of it.
Related Articles From In the Same Boat
- My Backcountry Photography series at Paddling.net
And one from my own website, too:
- "Exposing Aperture, Shutter Speed, and Depth of Field"
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