Buyer's Guide 2007: Lens Strategy
How to select the right mix of lenses for your photography
A prime lens has a fixed focal length. Before the advent of zoom lenses (which allowed photographers to choose from a range of focal lengths in a single lens), prime lenses meant that to get the coverage of a 20mm, 50mm and 80mm lens, the photographer had to carry a 20mm, a 50mm and an 80mm lens. For a professional with an assistant who carries the extra baggage, primes aren't too much trouble. But for most of us, the ability of a zoom lens to cover a range of focal lengths in a single unit is quite a bonus.
So why aren't all lenses zooms? Prime lenses have long been thought of as sharper than zooms. While that's sometimes still the case today, improvements in optics and lens design have made many zooms just as sharp as primes. Primes and zooms also differ in their elements-the individual pieces of glass that make up the lens. Zooms often contain more elements, and this unfortunately not only makes the lenses heavier, but it also increases their opportunities for flare, which can desaturate colors and even obliterate image detail.
When precision optics, low weight, compact design and fast maximum apertures are all important, first check out a prime lens. Canon's EF 85mm ƒ/1.2L II USM lens is a medium telephoto prime lens, designed for use on both film and digital camera systems. At ƒ/1.2, it's more than three stops faster than the widest aperture of an ƒ/4 lens. Ideal for portraiture and wedding photographers, this newly redesigned photographer favorite includes aspherical glass, faster autofocusing and distance communication with E-TTL I flash. The drawback? Perfection doesn't come cheap.
For an absolutely minimalist lens experience, consider the smc P-DA 21mm AL Limited prime lens from Pentax. This ƒ/3.2 designed-for-digital, wide-angle prime incorporates a hybrid aspherical element to reduce multiple aberrations, as well as a floating mechanism designed to adjust aberration compensation, depending on the focusing distance. Most remarkably, this 21mm lens is only 25mm long-that's one inch from the front element to the rear mount. And at only 4.9 ounces, it's one of the smallest and lightest SLR lenses available. Try finding that in a zoom lens! The lens fits Pentax KAF-mount camera bodies.
|Lenses have made huge strides in capabilities and quality over the past few years. Even inexpensive lenses offer excellent results.|
Still, there has been little unique in the design and use of a lens-until Lensbabies came along (www.lensbabies.com). These are special lenses with a look, design and capabilities that no other lenses have. Results from the three models are funky and creative, but for that reason, they won't appeal to everyone.
Basically, a Lensbaby lens is made to deform in its mount, which changes how it focuses on your sensor. The Original and 2.0 are built into a flexible tube (like a bellows), and you move the lens in and out, side to side and tilt it with your fingers in order to create distinctive focus effects where one part of the subject is sharp and other parts are blurry.
The newest model, the Lensbaby 3G, adds three focusing rails (plus a barrel focus mechanism) to allow you to lock the lens position into place, while including a release-and-lock button for instant lens adjustment. All models use a unique, interchangeable ƒ-stop system, and they're all priced quite reasonably.