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Comparative Digital SLR Lens Review: Fast, Wide Aperture Lenses

Field Test Report

Peter Burian tests five lenses with great light gathering ability: the Canon EF 70-200mm f/4L IS USM, Tamron AF 70-200mm f/2.8 Di LD (IF) Macro, Tokina AF 50-135mm f/2.8 AT-X Pro DX, Nikon 17-55mm f/2.8G ED-IF AF-S DX and the Sigma AF 30mm f/1.4 EX HSM DC

Because most digital SLR camera owners demand compact, lightweight lenses, the vast majority of zooms feature a small maximum aperture. A typical kit lens is designated as f/3.5-5.6 indicating that the maximum aperture is quite small at the short end and becomes very small at longer focal lengths. In practical terms, that translates to moderate light gathering ability. The larger the numeral the smaller the opening in the lens and the less light that will reach the camera’s digital sensor.

A wide aperture lens is ideal for fast shutter speeds in low light conditions when you cannot use flash or a tripod. Shooting at f/2.8 allowed me to get many sharp photos at 1/125 sec. during a stage performance, using ISO 1000. With a more typical (smaller) aperture, much higher ISO levels would have been required for the same shutter speed and the images would have been seriously degraded by digital noise. (Nikon 17-55mm at f/2.8.) (c) 2009 Peter K. Burian

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Q and A: What kind of scanner will fit my needs?

Question

I need to buy a high resolution scanner to digitize tons of slides and negatives when I retire in September. Can you compare film scanners and flatbeds with a transparency adapter for performance in creating digital files from 35mm film, suitable for making 13×19 inch prints with an Epson 2880? Which type would be the best bet? Philip Renaud

Answer

Thanks for your question, Philip. A full assessment would require a test of several brands/types of scanners, a major undertaking that’s not possible for the Q&A. But based on my research — and experience with scanners of both types — I’d say you should be satisfied with a top-of-the-line flatbed or a dedicated a film scanner. Frankly, such equipment is not inexpensive but either type should provide the level of quality you’ll want from the scans for making 13×19″ prints. (more…)