Tamron has updated its higher-end 17-50mm zoom lens with its vibration compensation technology to counteract camera motion.
The company released a 17-50mm model with a constant F2.8 aperture last year, but updated it with vibration compensation to a new model called the SP 17-50mm F/2.8 XR Di II VC. Tamron added the new feature "without materially increasing its size and weight," the company said.
But one thing is different: price. The earlier version costs about $450--and note that it's not being discontinued--while the image-stabilized version costs about $650. Tamron is selling a Nikon version initially and a model for Canon SLRs shortly afterward, it said.
The lenses are designed for mainstream SLRs with smaller image sensors--called DX by Nikon and APS-C by Canon--not the high-end full-frame cameras that cost much more but behave the way SLRs did in the 35mm film era. In 35mm camera terms, Tamron's models have a focal length range equivalent of about 26-78mm.
This wide-angle zoom range is useful for mainstream photography, but customers often already have a lens of that variety. "Kit" lenses that come with many entry-level models have a 18-55mm range.
But the Tamron 17-50mm lens, like a $1,000 Canon 17-55mm model, has a much wider F2.8 aperture than the Canon and Nikon kit lens' range of F3.5 at 18mm and F5.6 at 55mm. The wider aperture means the camera works much better in low-light situations. More expensive models also typically have more durable construction and better optical properties such as sharpness and low distortion.
I'm a little old-school, though, and I recommend people who want an upgrade try 50mm fixed focal-length lenses. They're relatively cheap--Canon's entry-level model costs $100 right now--and fast, typically with even wider F1.8 apertures. Some people who grew up with zoom lenses hate focal-length "prime" lenses, but I enjoy working within the constraints.