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Sigma Digital Lenses
A normal lens is light in weight and approximates the perspective of the human eye. Normal lenses generally have large maximum apertures, indicated by small f-numbers such as f/1.4 or f/1.8, and thereby gather much more light than zoom lenses. It may be possible to take a photo with a normal lens in light only 1/8th or 1/16th as bright as would be required for the same photo with a consumer-priced zoom lens. Also, the viewfinder will be brighter and therefore easier to use in dim light, due to the fact that the large maximum aperture stays open for viewing and stops down to whatever aperture you have set just before taking the picture. The Sigma lenses appropriate for a full-frame sensor or 35mm film camera are denoted with a "DG". The Sigma lenses appropriate for small-frame sensor cameras are denoted with a "DC". You can use DG lenses on crop sensor cameras but you can't use DC lenses on full frame cameras without vignetting. Sigma 30mm f/1.4 EX DC Sigma 50mm f/1.4 EX DG HSM Most of the world's great photographs were taken with fixed focal length lenses, not zooms. Partly this is because fixed or "prime" lenses are higher in every aspect of optical quality. Partly this is because a photographer with only one focal length available trains his or her eye to look for compositions that will be effective with that focal length. The "normal" perspective lens is the easiest for most beginners, because the perspective is similar to what one sees with the naked eye. On a 35mm film camera or full-frame sensor digital camera, the normal lens is a 50mm. On a small-sensor digital SLR camera, e.g., Canon Rebel XT or Nikon N70s, the equivalent would be a 30mm lens. Nikon and Canon both make wonderful 50mm prime lenses, but neither company makes a 30mm prime lens. That's why this Sigma lens, which costs around $450, is such a great find. If your kit zoom lens has a maximum aperture of f/4, that means you will need 8 times as much light to take a photo as you would need with the Sigma 30/1.4 set to f/1.4. With your kit lens, you must turn on the flash indoors, blasting everyone with an unflattering central light. With the Sigma, you keep the flash off and capture the light that you see with your eyes. One added bonus of the Sigma 30/1.4 is that it has an "HSM" or "hypersonic" motor. This is equivalent to Canon's "USM" (ultrasonic motor) or Nikon's "SWM" (silent-wave motor) and allows the photographer to use autofocus, but adjust the focus manually if desired. Wide-to-Telephoto Zoom A wide-to-tele zoom is what you get as a standard "kit" lens with a consumer-grade digital SLR body. The range goes from moderately wide through normal to moderately telephoto. They are good when you are too busy to change lenses, e.g., at a wedding reception. A 16mm focal length at the wide end will capture a table of guests; the 45-55mm long end is good for a flattering portrait. The main weakness of these lenses is that the cheaper ones have a very small maximum aperture, e.g., f/4 or f/5.6, and can only be used in bright light, on a tripod, or with a blast of on-camera flash that is not very flattering. Sigma 17-70mm f/2.8-4.5 DC Macro Sigma 17-70mm f/2.8-4.5 DC Macro HSM Sigma 18-50mm f/2.8 EX DC Macro Sigma 18-50mm f/2.8 EX DC Macro HSM Sigma 18-50mm f/3.5-5.6 DC Sigma 18-50mm f/3.5-5.6 DC HSM Sigma 18-125mm f/3.8-5.6 DC OS Sigma 18-125mm f/3.8-5.6 DC OS HSM Sigma 18-200mm f/3.5-6.3 DC OS Sigma 28-300mm f/3.5-6.3 DG The kit zoom lenses are too slow, with maximum apertures of f/4 or f/5.6, and too cheap optically. The consequences are that you need to use a flash more of the time and your pictures lack contrast and sharpness. The best solution to both problems is a set of prime lenses, but these can be cumbersome to carry around and change. If you like the idea of a single zoom lens for walking around, the Sigma 18-50mm F2.8 EX DC is a reasonable choice at around $500. Canon does not make a lens like this. Their fast f/2.8 zooms tend to be designed for film and full-frame sensor digital cameras such as the EOS 5D. Nikon makes a 17-55/2.8 lens that is very high quality, but it is more than twice the price of the Sigma. This range of focal lengths is good for photographing a wedding reception or other social event. Wide-angle Zoom Lenses Sigma 10-20mm f/4-5.6 EX DC Sigma 10-20mm f/4-5.6 EX DC HSM Sigma 12-24mm f/4.5-5.6 EX DG Sigma 12-24mm f/4.5-5.6 EX DC HSM Sigma 17-35mm f/2.8-4 DG Sigma 17-35mm f/2.8-4 EX DG HSM If you want to experiment with ultra wide angle photography and not spend more than about $500, the Sigma 10-20 is a reasonable choice. The Canon and Nikon equivalents either don't go as wide, are more expensive, or both. Because of its slow maximum aperture, f/4 to f/5.6, this is a lens to be used outdoors or on a tripod. [If you have a Canon Digital Rebel or similar small-sensor Canon EOS body, and can stretch your budget to $700, the Canon 10-22/3.5-4.5 zoom lens is a better performer.] Standard Zoom Lenses On a full-frame sensor camera, the standard zoom lens offers a great perspective for wedding and event photography. From a moderate wide to moderate telephoto, the range covered is flexible and very useful. They are also good when you are too busy to change lenses, such as at a wedding reception or a social event. The 24mm focal length at the wide end will cover a flattering perspective of the wedding party formals; the 60 or 70mm long end is good for portraits. Make sure you test before you buy. Whether you're a Canon, Nikon, Pentax, Sony, or Olympus photographer, compare the equivalent lens by the manufacturer to the Sigma to see if the money you are saving is not compromising image quality. Sigma 24-60mm f/2.8 EX DG Sigma 24-70mm f/2.8 EX DG Sigma 24-70mm f/3.5-5.6 HF Sigma 28-70mm f/2.8 EX DG Sigma 28-70mm f/2.8-4 DG Telephoto Zoom Lenses Telephoto zoom lenses offer flexibility at a distance. Whether you are photographing wildlife or sports/action, it's helpful to have a flexible rather than a fixed focal length. However, on some lenses this could mean a compromise in sharpness and image quality on either end, since the lens is covering a wider range. Also, some lenses are slower and will work best during daylight hours. Travis Hoover: Sigma 50-150, Nikon D40x Sigma 50-500mm f/4-6.3 EX DG APO HSM Sigma 50-150mm f/2.8 APO EX DC HSM Sigma 55-200mm f/4-5.6 DC Sigma 55-200mm f/4-5.6 DC HSM Sigma 70-200mm f/2.8 APO EX DG Macro HSM Sigma 70-300mm f/4-5.6 DG Macro Sigma 70-300mm f/ APO DG Macro Sigma 80-400mm f/4.5-5.6 EX DG OS Sigma 100-300mm f/4 EX DG IF Sigma 100-300mm f/4 EX DG IF HSM Sigma 120-300mm f/2.8 DG Sigma 120-400mm f/4.5-5.6 APO DG OS HSM Sigma 135-400mm f/4.5-5.6 APO DG Sigma 150-500mm f/5-6.3 APO DG OS HSM Sigma 200-500mm f/2.8 APO EX DG Sigma 300-800mm f/5.6 DG Wide-angle Prime Lenses Wide-angle Sigma Digital Lenses let you get close to your subject while still showing a lot of background information. A dramatic wide angle for a small-sensor DSLR is 16mm or shorter (calculating the multiplication factor). Fisheye lenses can add some cool effects to a photograph if you're into that type of image. For most applications, however, such as wedding, event, and architectural photography, you may want to go with a non-fisheye wide-angle prime lens approach, such as the Sigma 20mm/1.8 or the Sigma 24mm/1.8. Sigma 4.5mm f/2.8 EX DC Circular Fisheye HSM Sigma 8mm f/3.5 EX DG Circular Fisheye Sigma 10mm f/2.8 EX DC Fisheye Sigma 10mm f/2.8 EX DC Fisheye HSM Sigma 15mm f/2.8 EX DG Diagonal Fisheye Sigma 20mm f/1.8 EX DG Sigma 24mm f/1.8 EX DG Macro Sigma 28mm f/1.8 EX DG Telephoto Prime Lenses A telephoto prime lens offers excellent image quality at long focal lengths due to a large maximum aperture and magnification of the subject, and can be handheld in low-light situations. When comparing a telephoto prime to a normal-to-telephoto zoom, although zoom lenses cover wide ranges, they usually have a smaller maximum aperture on the long end. Keep in mind that on a crop sensor, the effective focal length of a telephoto prime is multiplied by 1.5. Sigma 300mm f/2.8 APO EX DG Sigma 500mm f/4.5 APO EX DG HSM Sigma 800mm f/5.6 APO EX DG HSM Macro Lenses Macro lenses let you photograph physically small objects. The longer the focal length of the macro lens, the more space you can put between the camera and the subject. Extra working distance is helpful in lighting scenes or keeping insects calm. A macro lens that goes down to "1:1" can be used to take a frame-filling photo of something that is roughly 23×16mm in size, the dimensions of the APS-C sized sensor on a Pentax digital body. The macro lenses below can be used for ordinary photographic projects as well, i.e., they will focus out to infinity if desired. Sigma 50mm f/2.8 EX DG Sigma 70mm f/2.8 EX DG Sigma 105mm f/2.8 EX DG Sigma 150mm f/2.8 APO EX DG Sigma 180mm f/3.5 APO EX DG If you are serious about taking pictures of people or pictures of small objects, you will want a single focal length or "prime" lens. The longer or "telephoto" macro lenses can serve both roles. Canon and Nikon both make some long macro lenses with fabulous performance, but they cost more than $1000. Sigma's is excellent and only around $600. A shorter macro lens, e.g., 60 or 100mm, will be cheaper, but you'll need to get closer to your subject. In the case of hummingbirds and insects, this might well be so close that they become disturbed. A shorter portrait lens will also be cheaper, but won't flatten your subjects features in as flattering a manner. The bigger your subject's nose, the farther away you need to stand when taking the picture and therefore the longer lens you need. This lens permits focusing down to a 1:1 image size. This means that you can take frame-filling pictures of objects as small as the film or digital sensor on your camera. If you have a small sensor camera, objects as small as 15×22mm in size will fill the frame. Note that this lens covers a full 24×36mm frame and therefore will work on any digital or film SLR, including the Canon EOS 5D. 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