The Sigma APO 300mm f/2.8 EX DG HSM lens is an ultra compact
Apochromatic telephoto lens with a fast f/2.8 maximum aperture, and
incorporates two Extraordinary Low Dispersion glass elements to reduce
chromatic aberration to a minimum. It incorporates internal focusing
which enables responsive and fast autofocus speed. A detachable tripod
socket and rotatable drop in filter holder are also included.
The improved DG lens design corrects for various aberrations.
This lens is specially coated to get the best color balance whilst
cutting down on ghosting caused by reflections from the digital image
sensor. The lens provides the utmost correction against lateral
chromatic aberration, which is a serious problem for digital SLR
With the use of the optional Sigma APO teleconverters,
this lens can be used as a 420mm f/4 AF ultra-telephoto lens with a 1.4X
EX teleconverter, or a 600mm f/5.6 AF ultra-telephoto lens with a 2X