Tuesday, January 6, 2009
Go from moderate to long telephoto with a single lens
Telephoto lenses tend to be large and often heavy, so one of the big advantages of a tele-zoom is that it can do the duty of the multiple lenses you would otherwise need to cover the same range, reducing the volume and weight of the gear you must carry. This bottom-line economy applies to price as well. The wider the range and the bigger the aperture, the more expensive the lens will be; but an investment in one good lens that covers a big range is more cost-effective than purchasing multiple lenses.
Ultrazooms like the Tamron model we include here go all the way from wide to long telephoto, and when coupled with the magnification effect of sub-full-frame sensors present in most popular D-SLRs, it’s possible to get telephoto lengths of 400mm and longer in a relatively affordable lens. For many photographers, a lens like this may be the only lens needed for most photo opportunities.
Remember that at longer telephoto lengths, a tripod or image-stabilization technology is important for getting sharp shots. Fortunately, many lenses now feature some form of stabilization, and some camera systems even build this into the body, so it works no matter what lens you choose.
Designed specifically for digital sensors, the Tamron Di II set of lenses is built for exclusive use on smaller-sized image sensors—thankfully so, because the AF18-270mm ƒ/3.5-6.3 Di II lens offers an incredible 15x zoom, covering an angle of view from a 29mm wide-angle to a 432mm telephoto (35mm equivalent). The lens includes Vibration Compensation (VC) for automatically detecting camera movement and compensating accordingly. Three hybrid aspherical lens elements and two Low Dispersion (LD) glass elements correct for aberration. The 18-270mm is available for Canon and Nikon mounts. Estimated Street Price: $599.
Featuring Sigma’s OS (Optical Stabilizer) function, the 18-125mm ƒ/3.8-5.6 DC OS HSM lens uses two sensors to detect vertical and horizontal movement. It then compensates for the detected shake with an optical image-stabilizing group, effectively offering up to four stops of blur reduction. Special Low Dispersion (SLD) glass combined with a molded glass aspherical lens and two hybrid aspherical lenses minimize aberration while providing high image quality. Multi-layer coatings also reduce flare and ghosting. A Hyper Sonic Motor and an inner focusing system ensure quiet and fast autofocus. The lens has a minimum focusing distance of 13.8 inches at all focal lengths, with a maximum magnification ratio of 1:3.8 for macro work. The 18-125mm is available in Canon, Nikon, Pentax, Sigma and Sony mounts. Estimated Street Price: $339.
The Sony SAL-70400G 70-400mm ƒ/4-5.6 G is a 5.7x super-telephoto zoom, the latest addition to Sony’s G-series of large-aperture, premium lenses. The lens is compatible with SteadyShot image stabilization in all Sony Alpha cameras, and uses internal focusing and an SSM system for fast and accurate autofocus all the way into telephoto. Extra-low dispersion glass is used for high contrast and uniform center-to-edge resolution while keeping aberration minimal. The nine-diaphragm aperture provides a smooth, natural, out-of-focus bokeh area when using a large aperture. There’s a focus-mode/range switch and three focus-hold buttons for extended focusing options, and the AF hold buttons also can be set to activate the Intelligent Preview function for reviewing and optimizing shots in-camera before they’re taken with the Sony Alpha A900 (a “full-frame” model). Estimated Street Price: $1,500.
With a bright ƒ/5.6 aperture at 400mm, the Tokina AT-X 840 AF D 80-400mm ƒ/4.5-5.6 (128-640mm 35mm equivalent) offers extreme telephoto with fast shutter speeds. The internal focusing system provides efficient auto and manual focusing. Optical multicoatings compensate for flare and ghosting. A tripod collar is included for attaching the lens rather than the camera, ideal when zoomed all the way out to telephoto range. A zoom lock switch locks to avoid zoom creep while the camera and lens are being moved. The included BH-725 lens hood uses a PL Assist spring-loaded thumbwheel to allow for filters to be rotated with the included lens hood in place. The AT-X 840 is available in Canon EOS and Nikon D mounts. Estimated Street Price: $649.
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