Of Sigma's 11 telephoto zoom lenses, the 300-800mm lens is the largest. This massive lens is 54.4cm (21.4 in.) long with a diameter of 16.5mm (6.1 in.). If 300-800mm doesn't provide enough zoom for the job, the lens can be further enhanced to 420-1120mm or 600-1600mm using a 1.4x EX or 2x EX apo tele converter, respectively.


Despite its size, the Sigma 300-800mm ultra-telephoto lens is relatively easy to handle. It has internal focusing and zooming, so that the physical length of the lens does not change. Also, "since the front of the lens does not rotate, a circular polarizing filter can be easily attached and used."

A new multi-layer lens coating helps to reduce common flare and ghost effects, while enhancing overall color balance. In addition,"two ELD glass elements in the front lens elements reduce chromatic aberration to a minimum and also ensure sharp, quality images of high contrast."

The lens's autofocus is both effective and fast, though there is always the option of manual focus override. Picture composition is aided by automatic and continuous adjustments to the angle of view, which oscillates between 3.1 and 8.2 degrees.

Price: $6,500

Specifications

Lens Construction	18 Elements in 16 Groups
Angle of View	8.2-3.1 degrees
Number of Diaphragm Blades	9pcs
Minimum Aperture	F32
Minimum Focusing Distance	600cm/236.2 in.
Maximum Magnification	1:6.9
Filter Size	46mm (drop-in type)
Dimensions	Diameter 165.5mm X Length 544mm 6.1 in. X 21.4 in.
Weight	5,880g/207.4oz
Corresponding AF Mounts	SIGMA, CANON, NIKON (D)