Taking A Broader View of Life - Wide Angle Photography

Transcription

1 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.

2 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

3 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

4 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 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 mm 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 f 3.5, although OK under some circumstances, generally exhibits marginal image quality. Avoid if possible. Olympus - The Olympus 12-60mm f 2.8 ($900) is an excellent and very sharp all-around lens. Although expensive, it s still a good buy for Olympus and Panasonic 4/3 camera owners. It s best at wider lens apertures and wide-angle magnifications. - On the other hand, Olympus s regular14-42mm kit lens is adequate but not great at wide-angle settings. The modified, collapsible 14-42mm M. Zuiko kit zoom lens included with Olympus s compact Pen E-P1, E-P2, and E-PL1 cameras is actually better optically. It s generally decent to good at wide-angle magnifications when set to f Somewhere in between is the Olympus 14-54mm f 2.8 Mark II zoom ($650). This is a very sharp lens that seems optimized for wider angle settings. Stopping down to just ƒ/4 produces excellently sharp images. If you don t need the wider range of the Olympus 12-60mm zoom, then this lens may be the best buy for Olympus and Panasonic owners. Panasonic - Although versatile, Panasonic s mm zoom does not excel at wider angles and edges are symmetrically soft, suggesting design limitations. - Similarly, Panasonic s14-45mm high end kit lens ($400) is generally sharp, although not exceedingly crisp, across the entire frame. This lens seems best at f 5.6

5 Pentax - Firstly, let s examine Pentax s best kit lens, the 18-55mm AL II. (About $120). This optional kit lens is very sharp at wide-angle settings, but only at smaller apertures. Still, it s one of the best kit lenses and a very good buy for Pentax and Samsung K-mount dslr owners. Pentax makes a number of other kit lenses in this same focal length range, such as the WR weather-resistant series, but I have not data for these. Pentax s older 18-55mm AL series (not the newer, better AL II) is OK but not great. - Pentax does make two very high quality, moderately priced normal range zoom lenses that include excellent wide-angle capabilities. The older Pentax 16-45mm f 4 zoom (under $400) excels at wider-angle magnifications, with excellent center sharpness and very sharp corners. This lens peaks between f 5.6 and f 8. - Pentax s newest, best normal range zoom is the 17-70mm f 4 zoom ($500). It s is very good, occasionally excellent, in the 17-24mm wide-angle range. It s optimized optically for normal to telephoto magnifications but still does quite well at its wide-angle settings. Sigma - Independent lens maker Sigma makes two lenses in this range. Sigma s 17-70mm F2.8 ($400) is very sharp, especially in the central third. It s a good all-around lens that s best at wide-angle to normal magnifications. - Sigma s F2.8 ($300) is not nearly as impressive as their 17-70mm zoom. I d skip this one despite its fairly low price. Even some free kit lenses are better Sony - Sony sells some excellent zoom lenses. Their 16-80mm f 3.5 Zeiss-branded zoom ($850) is extremely sharp at both wide-angle and longer focal lengths. - Sony s newer 18-55mm f 3.5 kit lens (termed the DT SAM SAL-1855, a real mouthful) is very sharp over the center 2/3 of the image but corners are a bit soft. Still, it s an excellent kit lens. Tamron - Tamron has one major product in this zoom range, the 17-50mm f 2.8 ($425), but it s very good to spectacular at most magnifications and apertures through f 8. Its optical performance is excellent, construction quality is very good, and it sells for a very attractive price. Models are made to fit nearly every camera mount, so it s a universal best-buy.

6 True Wide-Angle Zoom Lenses: In addition to wide-to-normal zooms, there are several excellent and affordable ultra-wide to wideangle zoom lenses available to users of most dslr brands. In contrast to the wide-to-normal category above, several ultra-wide zoom lenses by independent lens makers Tokina, Sigma, and Tamron are very good to excellent optics, fit most dslr models, and are relatively affordable. These are often as good as their name brand competition and usually less expensive, although none of these lenses are exactly cheap. All of the lenses listed here are rectilinear, that is, they render straight lines as straight lines. Fisheye lenses are, in my opinion, something of an over-used novelty and are not included here. Despite their short focal lengths, ultra-wide angle zoom lenses tend to be bulky, a result of the complex designs necessary to provide sharp focus and even illumination over a very wide field of view. Overall first place as a best buy goes to the Tokina 12-24mm f 4 lens and its Pentax counterpart. This is an excellent and very sharp lens throughout most of its zoom range, at least when stopped down slightly to f 5.6 to f 8. Resolution becomes somewhat soft toward the 24mm upper end of its magnification range unless you stop down to f 11. This 12-24mm lens includes models that fit most dslr bodies. It has a 35mm equivalent zoom range of 18mm ultra-wide-angle through 36mm slightly wide-angle magnifications. Many reviewers consider this lens to be a basic standard of comparison for wide-angle zoom lenses because of its high optical quality relative to price. Tokina and Pentax are part of the same Hoya holding company - the only difference between these two lenses is that the Pentax version includes more efficient multicoating that further reduces internal reflections and flare, frequently the bane of complex wide-angle lenses like this. Both lenses are very well made. The 12-24mm Pentax is somewhat more expensive at about $700 and works with both Pentax and Samsung dslr cameras. One of these lenses should satisfy the wide angle urges of nearly any photographer. - Tokina also makes a newer 11-16mm f 2.8 ultra-wide-angle zoom ( about $600) which has a very short zoom ratio, with a 35mm equivalent range of 17mm to 24mm. Again, the optical quality of this lens, particularly overall sharpness, is very high considering its extremely wide field of view, large maximum aperture, and moderate cost. This is a well-made lens and definitely another best buy. The only noticeable optical concerns with this lens, chromatic aberration and vignetting at the shortest focal lenghts, can both be readily corrected in Adobe PhotoShop or Lightroom. - Sigma, another independent lens maker, sells 10-20mm f 4 ultra-wide-angle zoom for most camera models. This is another well-made lens usually selling for around $600. Overall, this is a fairly sharp lens - center sharpness is quite good but the corners are noticeably softer than the Tokina zooms above. Unusually, this lens is also available for Olympus and Panasonic Four-Thirds cameras.

7 - Sigma s 12-24mm f 4.5 zoom (usually between $700 to $800) is a very complex design inside a solid lens body. Although it s a decent performer with good center resolution, the Tokina and Pentax 12-24mm lenses have somewhat higher sharpness even though they re less expensive. Moreover, the bulging front element of this Sigma lens prevents mounting a protective UV filter. - Tamron s 11-18mm wide-angle zoom currently sells as low as $405. Despite that low price, it s no bargain due to high optical distortion and poor sharpness, especially away from the center of the frame. - Tamron s10-22mm f 3.5 ultra-wide zoom (about $500) is a newer model that s much better. Sharpness over the central two-thirds of the picture is high at the widest angle settings, if you stop down to f 8, but corners are always a bit soft, no what aperture you choose. Toward the upper end of the magnification range, sharpness generally declines. This lens provides good value. - Tamron s 17-35mm f 2.8 zoom ($400-$450) can be used on both APS-C and large full frame sensor cameras. This can be a very sharp lens, particularly when only the central lens image area is used by an APS-C camera. When used wide open at its largest apertures, most of the frame is fuzzy, but stopping down just one or two stops to f 4 or f 5.6 dramatically improves overall image quality. On a full frame sensor, you ll get an even wider angle of view but you ll need to stop down to f 8 or f 11 in order to get good image quality. - Sony s 11-18mm f 4.5 zoom ($700) is fairly sharp in the center of the image but generally suffers from fuzzy corners. Some of the third party lenses do a better job for less money and have sharper corners as well. - Panasonic s 7-14mm f 4 zoom (about $950) fits Four-Thirds and Micro Four-Thirds cameras made by Panasonic and Olympus. On a 4/3 sensor, this 7-14mm lens acts has a 35mm equivalent magnification of 14mm to 28mm. This is a wickedly sharp lens for cameras that can mount it and optical distortion is surprisingly well-corrected as well. Overall, it is one of the sharpest lenses that I ve seen, especially considering its daunting and tricky ultra-wide-angle field of view. Although expensive, it s worth every penny if you can use it. - Olympus has announced several ultra-wide-angle lenses for Four-Thirds cameras but there s no test data available at this time, so I can t comment upon them. - Nikon s 12-24mm f 4 zoom (about $1,000) is impressively sharp at all magnification ranges if you stop it down to f 5.6 or f 8. However, I believe that some of the third party lenses discussed above are better buys, even for Nikon users. - Nikon s 14-24mm f 2.8 zoom ($1,650) actually works corner to corner on a full frame sensor, if you can believe that, and it s very sharp across that big sensor area despite the extraordinarily wide field of view for a rectilinear ultra-wide-angle lens. It s comparably sharp on smaller APS-C sensor Nikons as well. Although this lens gives me severe sticker shock, it s probably a case where you get what you pay for. It s even sharp at wide apertures. Wow! - Nikon s 10-24mm f 2.8 ($900) is another very sharp ultra-wide-angle lens from Nikon, one that works only with smaller APS-C sensor Nikon s. I could find no fault with this lens given its price range. It s sharpest at medium apertures like f 5.6 and good at all focal lengths.

8 - Canon s f 3.5 zoom ($725) is another good ultra-wide zoom lens. Between its widest 10mm setting and about 18mm, it s very sharp across the entire frame at f 5.6 and f 8. Edges tend to be somewhat fuzzy toward its longest 22mm focal length regardless of aperture. Still, this is a very good choice for APS-C Canon users at a fair price. Recommendation: Most users really don t need, and won t use, ultra-wide-angle zoom lenses to their full capability. They ll likely will be satisfied with a high quality normal range zoom lens that includes a 16mm or 17mm minimum magnification. Not only are such lenses less expensive but they re more versatile, covering a range between 24mm (equiv.) extreme-wide-angle through the equivalent of a 75mm or so moderate telephoto magnification. Among the better OEM lenses in this group are the Canon 15-85mm, the Olympus 12-60mm, the Nikon 16-85mm, the Sony 16-80mm, and the Pentax 16-45mm and 17-70mm lenses. Tamron s 17-50mm f 2.8 normal range zoom is probably the best buy in this group. It s very sharp at most settings, well-built, and relatively inexpensive. Tamron makes versions of this lens that fit most dslr cameras. If you decide that you really do want to go very wide, then Tokina s 11-16mm and 12-24mm lenses are probably your best value in a generic ultra-wide-angle zoom. The Pentax 12-24mm zoom is basically the same design with some additional optimization - it s the best buy for Pentax owners. There are some very nice OEM ultra-wide-angle zoom lenses made by major camera manufacturers but you should expect to spend more. Panasonic s 7-14mm seems to be the lens of choice in this category for 4/3 users while the Canon 10-22mm zoom and all three Nikon ultra-wide zooms will provide excellent optical performance if you re willing to pay the price.