The lens is more compact than the current Sigma 18-250mm lens and its macro capability has a maximum magnification ratio of 1:2.9 and uses Thermally Stable Composite (TSC) material currently used only by Sigma. TSC contributes to the lens’s size reduction. The non-macro 18-250mm f/3.5-6.3 without TSC weighs 22.2 ounces and is 3.1×4 inches in diameter, whereas this new Sigma macro lens is 16.6 ounces and 2.9×3.5 inches in diameter.
The Sigma lens has an approximate 13x zoom ratio with a filter size of 2.8 inches in diameter. Sigma’s OS system, one special low-dispersion glass and three aspherical lens glasses work to compensate for camera shake and enable correction of color aberration, respectively. The lens is also equipped with super multilayer coating to reduce flare and ghosting, a hyper sonic motor (HSM) to help ensure fast, quiet autofocusing, and a rounded, seven-blade diaphragm to create an attractive round blur to the out-of-focus areas. Also featured is a brass-made bayonet mount applied on the surface to reinforce strength for long-term use.
This lens is available in Sigma, Sony, Nikon, Canon and Pentax mounts, starting with Canon mounts coming in July 2012. Pricing and availability for other mounts have yet to be announced. sigmaphoto.com