|Sigma 28-135mm f3.8-5.6 Aspherical IF Macro is one of several lenses introduced at PMA 2000 by Sigma Corporation. Incorporating aspherical optics, plus a floating inner focusing system, this lens minimizes spherical aberration and stigmatism. This lens can focus from infinity to 19.7 inches at all of the focal lengths without close-up accessory, and as close as 9.4 inches (1:2 reproduction ratio) at the 135mm zoom position. This lens incorporates an inner focusing system and features a non-rotating front lens barrel for convenient filter use. A custom designed "Perfect Hood" with bayonet mount is provided to prevent extraneous light from degrading the image quality.