Lens Reviews

A tilt-shift lens can be thought of as a flexible visual tool in the many ways it allows you to image the world. Unlike a standard lens, even a zoom, with a set point of view enforced by stance, elevation, focal length, and, within certain limits, depth of field, the tilt-shift lens opens visual doors a “fixed” lens will not. By tilting the lens within the mount you can enhance or greatly diminish depth of field beyond the “normal” abilities of the focal length and aperture setting. By shifting the lens you can “fix” perspective distortion or exaggerate it for “trick” effects.

The 70-200mm focal length has been the standard tele-zoom choice for many years, offering near normal to a good tele range that suits many practical purposes. Yet, quite a few stock-in-trade 70-200mm lenses had been slow or lost significant aperture as soon as you left the shortest zoom setting, making them a real challenge for handheld, low-light, or even max focal length shooting. Certainly, improvements in sensors and processors in terms of the high ISO/image quality ratio have helped. If you’re too slow on shutter speed with a variable aperture zoom you can always jack up the sensitivity. But that’s not always a great choice and it seems to force you to compromise image quality just to make up for the lens losing “speed” just when you need it most.

While the Sigma 150mm f/2.8 lens has been out for a good while we decided to take a closer look at one of the most interesting pro-oriented products in their lineup. One of the key selling points in this lens is built-in optical image stabilization (“OS” in Sigma-speak) to aid in achieving camera-shake-free, handheld exposures. Granted, image stabilization in a macro lens is not the be-all and end-all of successful close-ups, though it sure gives added insurance. And because the Sigma 150mm OS macro is optimized for full-frame D-SLRs, it allows for use at the stated focal length with such cameras and provides even greater effective focal length with APS-C-type SLRs.

There are a number of new lenses, including those for “full-frame,” Micro Four Thirds, and “mirrorless” compact system cameras debuting this year, listed in alphabetical order. Here’s a sampler, with a sprinkling of filters thrown in for good measure. We’ve shown prices when available at press time—if not, check the websites of the companies for updates.

The difference between a “constant” aperture zoom and other standard zooms is that when you increase the focal length on the standard zoom the maximum aperture narrows. This might make the difference between being able to hand hold or not when zooming in, and may indeed force the use of higher ISOs. Known as “fast” lenses, constant aperture zooms are pricier and bulkier than their variable-aperture counterparts. And to sweeten the pot, we’ve seen more and more fast lenses with built-in image stabilization, which gets you even more low light and steady shot capability.

The Sigma 85mm f/1.4 EX DG HSM lens (average price: $969 on various Internet sites) is designed for full-frame cameras; with an APS-C multiply by your usual factor. At about 25 oz, I’d describe the lens as substantial, but not hefty. One of the reasons for the weight is the build—11 elements in eight groups, including the use of SLD glass, Sigma speak for Special Low Dispersion. The big chunk of glass on the end requires a 77mm filter. As to handling, Sigma has gone from their black “crinkle” finish to a smooth black rubberized finish that feels great to the touch. It’s plastic, not metal, but based on my experience with previous Sigma lenses, I’ve found them to be built to professional standards and can take a lot of abuse.