Typical macro lenses -- normal to telephoto focus length range – usually have maximum aperture at F2.8 or slower, with the exception of Olympus Zuiko Digital 50mm F2.0 ( Four Thirds lens) at one stop faster. Tamron has today announced the development of SP AF 60mm ƒ/2 Di II LD (IF) Macro 1:1. Like the Olympus, it’s a digitally optimized Macro lens featuring a bright maximum aperture of ƒ/2.0.
Technically, the SP AF 60mm is a medium telephoto macro lens with 35mm equiv. focus length distance of 90mm for 1.5 crop sensor, or 96mm for 1.6 crop sensor APS-C size digital SLR cameras; but based on Tamron’s conversion, the value is 1.55X.
It’s a true macro lens with life-size magnification from working distance of 100mm and first-of-its-kind to realize the fast maximum aperture of f/2 at that focus distance. Also, the optics features an internal focusing mechanism (IF), two special Low-Dispersion glass elements, and lens-construction from 14 elements in 10 groups with Broad-Band Anti-Reflection coating.
For macro works, a fast aperture is not practical when getting close to the subject. DOF reduces as the aperture gets largest (smallest F value), and most macro lenses are lacking sharpness at wide open. However, it would be useful for Abstract Macro photography where the artistic presentation is often expressed with much shallow DOF.
Tamron has not announced price and availability for the new macro lens. Initial rollout will cover the mountings for the Big-Three -- Nikon, Canon and Sony.