Taking A Broader View of Life - Wide Angle Photography By Joe Kashi Sometimes, it’s fun to step back from our typical, constrained view of the world and see the big picture. It’s all a matter of finding a fresh perspective. Finding a new point of view often makes sense in our daily lives and in our politics. It’s also true in photography. In fact, recent neuropsychology research suggests that one of the best ways to avoid mental deterioration as we age is to deliberately expose ourselves, with an open mind, to points of view with which we do not already agree or that are different from our daily routine. Wide-Angle Visual Effects Photographs made with wide-angle lenses often show an obviously distorted perspective - nearby objects seem much larger while distant objects appear unusually small. That often startles less experienced photographers who might reach for a very wide-angle lens hoping to capture the entirety of a dramatic mountain range. Yes, you’ll get many mountains into the photograph, but they’ll look small, insignificant and disappointing. On the other hand, you can use that sort of distorted perspective to your advantage, making striking photographs in which the foreground is greatly emphasized. As a matter of basic physics, your depth of field (the overall area in reasonably sharp focus) will be much greater when using a wide-angle lens, so a lot more will be in focus. Although that may result in images that seem sharper overall, great depth of field may reduce your ability to emphasize the main subject, which is usually done by using a very shallow depth of field to throw the background out of focus, blurring it. My personal style of photography tends toward using higher magnification lenses that zero in upon smaller, more detailed areas. However, under the right circumstances, a 21 mm to 24 mm (35mm equivalent) extreme wide angle lens can result in some very dramatic images and I always try to carry one with me. Just in case. What To Look For: Designing and manufacturing a quality wide-angle lens, even a fixed magnification one, is exceptionally complex because we must bring a very wide angle of view into uniformly sharp, flat focus even though the corners of a wide-angle photograph are much farther away from the lens than the photo’s center. As a result, the edges and corners of a wide-angle photograph tend to be fuzzy compared to photos made with normal angle lenses, especially at wider apertures. Corners may be also noticeably darker, a phenomenon called vignetting. Another problem common to most wide angle lenses is optical distortion, which bends straight lines. Both vignetting and optical distortion usually can be corrected to a large degree using the PhotoShop software but there’s not much that you can do about fuzzy corners and edges. Ideally, all of these problems are avoided by purchasing a wide-angle lens that’s sharp and well-corrected from corner to corner. Really good wide-angle zoom lenses are even more difficult to make than fixed magnification lenses. As a result, higher quality wide-angle zoom lenses tend to have a very short magnification range, on the order of 2X. They are often physically larger in order to gather enough light to evenly illuminate that wide-angle view. Due to slight deficiencies in manufacturing and assembly, different copies of the same lens design will often show some variations in optical performance but these usually become negligible at smaller lens openings. In any event, for best results, reducing your lens aperture to about f 5.6 to f 8 will almost always produce the sharpest results, especially at the corners. Which Lenses Are Wide? What constitutes a wide-angle lens? Generally, the term applies to any lens with a wide field of view and a focal length that’s less than the diagonal width of the sensor or film. There’s a lot of variation in the field of view that a given lens may produce on different digital SLR cameras. In order to consistently understand how a lens will perform optically on a specific camera, we need a common denominator to make an apples to apples comparison of visual effects. The traditional 35 mm film camera is still used as a nearly universal comparative measure. In traditional 35mm film camera terms, a lens with a magnification equivalent to a 50 mm lens, would be considered to be a “normal” angle lens, while a 35mm equivalent lens would be a slightly wide-angle lens. A 28 mm equivalent lens is considered to be a true wide-angle lens while a 24 mm or a 25 mm equivalent lens is more of an “extreme” wide angle. “Ultra wide angle” lenses would have a magnification comparable to 18 mm to 24 mm lenses on a 35mm film camera. A 28 mm (equiv.) or shorter lens will usually show obvious wide-angle optical effects. In comparison, a lens magnification equivalent to 85 mm to 105 mm usually looks the most natural to people, which is why portrait photographers tend to use such lenses. Personally, I usually don’t go wider than 24 mm (equiv.). Most interchangeable lenses are now designed for digital SLR cameras that use an APS-C sensor that’s somewhat smaller than traditional 35mm film. In order to convert the visual effect of an APS- C camera lens into its general 35 mm magnification equivalent, you must multiply the lens’s actual focal length by a conversion factor. The conversion factor for most APS-C dSLR cameras is 1.5X, which means that a 24mm APS-C lens setting would be equivalent to the slightly wide-angle view produced by a 35mm to 36mm lens on a traditional 35 mm film camera. All Four-Thirds and Micro Four-Thirds cameras have a 2X conversion factor, so an 18 mm lens on a Four-Thirds dSLR camera would produce a field of view equivalent to a 35 mm lens. Canon dSLR cameras have a 1.6X conversion factor, resulting in a view that’s slightly magnified compared to other APS-C cameras. Do You Need One? There are some exceptionally fine wide-angle zoom lenses available at fairly reasonable prices, but you may not need one. If you don’t require a lens whose angle of view is wider than 16 mm or 17 mm (24 mm to 26 mm equivalent), then a high quality “normal” range zoom lens may prove less expensive and more versatile, yet at least as good optically, particularly when used at medium apertures like f 5.6 to f 8. Standard Zoom Lenses With A Wider View Firstly, let’s look at “normal” range zoom lenses that include very good wide-angle capabilities. For most interchangeable lens digital SLR cameras, wide-angle optical effects are evident at an actual 18mm focal length, with more extreme optical effects occurring in the 14mm to 16mm range. A photograph cannot be sharper than your lens, no matter how much you spend on a camera body, even a hyper-expensive model using a full-frame sensor. Although software manipulation, when appropriate, can deliberately blur detail and soften images from a sharp lens, software cannot fix images made with a poor-quality lens. The detail must be present in your initial image. Top quality modern lenses are potentially sharper than most camera bodies. Luckily, some fairly inexpensive “normal” range zoom lenses are both quite sharp and very versatile. All major manufacturers offer at least one high quality zoom lens in this magnification range, as do independent lens makers Tamron and Sigma. Our overall “Best Buy” recommendation in the wide to normal zoom range is the Tamron 17-50mm f 2.8, which is affordable, optically excellent, and available for nearly all dSLR cameras. In addition to the Tamron 17-50mm zoom, let’s look at some other lenses in this optical range: Canon - Canon’s newest 18-55mm kit lens, included with Canon’s consumer-grade dSLR cameras, is fairly good at wide-angle settings. Try this one before buying something more expensive. It may be adequate for your needs. - Canon’s 15-85mm EF series zoom ($760) is my choice as Canon’s best value for a highly versatile extreme wide angle through medium telephoto lens. It’s very sharp across the middle 3/4 of the frame but the extreme corners are a bit soft. Still, this is an excellent performance, especially given its versatility and relatively low price. It’s a best buy for serious Canon fans. - Canon’s pro-level 17-55mm f 2.8 L series zoom costs nearly $1,000, but is very good to excellent at wide angle. Canon’s15-85mm EF lens is a better buy for most people. - Canon’s older 17-85mm zoom is quite poor at wide angle settings. It’s not even as good as the current Canon kit lens. Nikon - Nikon’s 16-85 f3.5 zoom ($675) is excellent at wide-angle settings and also very versatile. It’s best at f 5.6 and f 8 because the corners are fairly soft at larger apertures. - Nikon’s current kit lens for its mid-range D90 dSLR camera is the Nikkor 18-105mm f 3.5 This lens, which costs about $300 if purchased separately is quite sharp at wide-angle settings although corners can be somewhat soft. This is probably a best buy for Nikon fans. - On the other hand, Nikon’s current low-end kit lens, the 18-55 f 3.5, although OK under some circumstances, generally exhibits marginal image quality.