By MICHAEL PERKINS
THERE MAY BE A STATISTICAL TABLE SOMEWHERE that breaks down the percentage of photographers who use telephoto lenses consistently versus those who only strap one on for special occasions, but I have never seen one. Of course, I’ve never seen a three-toed sloth either, and I’m sure they exist. Fact is, there are always enough telephoto newbies (or “occasional-bies”) out there to guarantee that many of us make some pretty elemental mistakes with them, and come home with fewer jewels than we hoped for. I should know, since I have produced many such “C-minus” frames, like the image seen above. For a better understanding of everything I did wrong here, read on.
If telephotos just had to deliver magnification, and otherwise worked the same as standard lenses, they wouldn’t produce so many problems. In fact, though, they need to be used in several very different ways. For one thing, zooming in exponentially increases not only the chance of camera shake but the visible results of camera shake. A little bit of tremble at 35mm may go undetected, with little discernible effect on sharpness, while the very same amount of shake at 300mm or above creates a mathematically greater amount of instability, rendering everything soft and mushy.
This means that handheld shots at the longer focal lengths are fundamentally harder to do. Solutions can include faster shutter speeds, but that cuts light at apertures of f/3.5 and smaller, where light is already diminished. You might get around that with a higher ISO, which may not produce acceptable noise on a brightly lit day, but you must experiment to see. If you simply must have longer exposures, you’re pretty much onto a tripod, and, if workable, a cable release or wireless remote to guarantee that even your finger on the shutter doesn’t create a tremor. Remember, you’re talking about very minor amounts of movement, but they’re all magnified many times by the lens.
Some people even believe that a DSLR’s process of swinging its internal mirror out of the way before the shutter fires can create enough vibration to ruin a shot at 400mm or further out. In such case, many cameras allow you to move the mirror a little earlier, so that it’s stopped twitching by the time the shutter opens. Lots of trial and error and home-bred calculus here.
One of the factors fouling many of my own telephoto shots comes from shooting at midday near major cities, adding both glare and pollution to the garbage your lens is trying to see through. Colors get washed out, lines get warped, sharpness goes bye-bye. For this, you might try shooting earlier, taking off your haze filters (’cause they cut light) and seeing if things come out clearer and prettier.
Telephotos are a fabulous tool, but like anything else you park in front of your camera, they introduce their own technical limits and challenges into the mix. Seldom can you get results by just swinging your subject into view and hitting the shutter. Get comfortable with that fact and you will find yourself taking home more keepers per batch.