Camera Lens Resources Washington DC
Silver Spring, MD
Lens Buying Guide
Lens Buying Guide
Everything you need to know about focal lengths, maximum apertures, new technologies and more!
A trip to the camera store these days will show you an astonishingly vast array of lenses, from tiny zooms on compact digital cameras to big telephotos for digital SLRs. Many of these lenses are based on designs that were unheard of just a few years ago. They offer you new opportunities to expand your photographic capabilities—knowing what the lenses can do for you will help you make a better decision in your camera and lens purchasing, whether that means checking the zoom range of an advanced compact, buying a new lens for a digital SLR or comparing lens speed among any group of lenses.
The best new glass for your D-SLR
Ask most pros which they’d rather have: an entry-level camera with a top-of-the-line lens or a rudimentary lens on a top-of-the-line camera. They’ll choose the top-notch glass every time. It’s not that cameras and sensors aren’t important, but a really great lens is invaluable. The lens is what delivers your subject, framing the world so you can put it in perspective.
Camera buyers often concentrate only on the camera, accepting whatever lens may happen to come with it. Astute photographers, though, quickly upgrade their lenses—and they’re quick to see results, too. Working with the right lens for your needs doesn’t necessarily mean you have to buy the most expensive glass you can find, only that you understand the many different features of lenses, the benefits they bring and what makes each lens unique.
Lenses are wide, normal or telephoto. A wide-angle lens usually measures less than 40mm in 35mm-equivalent terms. Normal lenses range from 40mm to 60mm or so, and telephoto lenses range from 70mm all the way up to 1000mm and beyond (although most common teles top out in the 300mm range).
Benefit: A wide lens is great for spreading out a scene—for instance, making a cramped interior look more spacious—and for getting lots of information into the frame to provide context. Normal lenses provide a distortion-free view, roughly the same as the human eye. Telephoto lenses are ideal for compressing scenes, covering a long distance in a narrow angle of view that brings far-away subjects close up.
PRIME VS. ZOOM
A prime lens has a fixed focal length: 20mm, 50mm, 100mm and so on. A zoom lens can be adjusted to any focal length within its range—say, 70-200mm and everything in between.
Benefit: Prime lenses often are lighter, faster and more compact than zooms, but to change focal length, you have to change lenses. Zoom lenses actually can be more convenient because a single zoom lens may do the job of multiple primes.
MACRO AND FISHEYE
A macro or micro lens is able to focus at very close distances. A fisheye lens has an extremely short focal length (such as 8mm or 10mm) and an extremely wide angle of view (beyond 100 degrees and often up to 180).
Benefit: Focusing on very small, very close objects makes it possible to achieve tremendous magnification, up to and beyond the 1:1 life-sized ratio considered to be the true measure of a macro lens. With a fisheye, the ultrawide options include full-frame lenses that cover a traditional 4x6 image or circular fisheyes that create a round image in the center of the frame—both making it possible to take in a huge “full-sky” field of view.
The term “speed” doesn’t reference how fast a lens focuses, but rather how efficiently it can get light through the lens and into the camera. A faster lens has a wider maximum aperture (ƒ/2) than a slower lens (ƒ/5.6). ...
Lenses: Designed For Digital
Lenses: Designed For Digital
What exactly are “designed for digital” lenses, and what makes them ideally suited for D-SLRs?
Far from simple marketing hype, the term "designed for digital" encompasses the entirety of lens technologies unique to the demands of image sensors and their various sizes. Unlike film, image sensors have a shiny, flat surface. That surface is prone to causing internal reflections of light that bounce back and forth between the image sensor and the elements within the lens, otherwise known as ghosting and flare. Along with that fundamental difference, image sensors capture light in a way that's simply different from film, and these differences have given rise to the new generation of lenses that now form the backbone of each manufacturer's lineup. Some of the key differences are reflectivity that causes ghosting, the need to bring all wavelengths of light to sharp focus on a single plane, coping with the magnification factor of smaller image sensors and capturing light from very wide-angle lenses without vignetting or introducing chromatic aberration.