Editor's Choice 2007: Advanced DSLRs

EDITOR'S CHOICE SLR Lenses

Best Buy: Sigma 50-150mm f/2.8 APO EX DC HSM

The focal length range on this zoom is more meaningful than it first seems. When used on a digital SLR with an APS-C-sized sensor, it's the equivalent of about 75-225mm, close to the 70-200mm (or 210mm) long valued for 35mm work. Reflecting its pro caliber, the lens's maximum aperture remains constant throughout that range, making handheld low-light photographs sharper even when you're zoomed in to longer focal lengths. Yet the lens is much lighter and smaller than a 70-200mm f/2.8 for full-frame SLRs, so handheld low-light photography is steadier and sharper -- aided by the four SLD (Super Low Dispersion) elements that give it its APO designation. Ultrasonic focusing makes AF operation fast and quiet; focusing and zooming are both internal, so the lens doesn't rotate or change in length. And close focusing of under 40 inches permits reproduction ratios up to 1:5.3. About $650.

Read more on the Sigma 50-150mm f/2.8 APO EX DC HSM. Next product: Lensbaby 3G for Medium Format.