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This high zoom ratio lens is optimized for digital SLR cameras and capable
of covering a wide range of focal lengths from 50mm standard to 500mm
ultra telephoto.
This ultra-zoom lens employs
a seven-group zoom system, which provides a high zoom magnification of
10x. Triple-cam Rear Focusing System ensures high precision throughout
the whole focus range. The new lens coating reduces flare and ghost, which
is a common problem of digital cameras and also creates an optimum colour
balance.
By attaching the 2X APO EX Tele-Converter, this lens can be used as a
200-1000mm/F10.4-12.6 manual focus zoom lens, while maintaining a very
compact size for 1000mm focal length. It is also possible to use AE (Automatic
Exposure) function, when EX Tele-converters are attached.
An apochromatic lens, which keeps color aberration to a minimum, using
Special Low Dispersion (SLD) or Extraordinary Low Dispersion (ELD) glass
is called an APO series lens at Sigma.
This lens uses four pieces of SLD (the special low dispersion) glass for
excellent correction of chromatic aberration. High optic performance is
demonstrated throughout the entire zoom range.
The HSM models (the HSM is only available for Canon, Nikon, Sigma and
Four Thirds Mounts) provide quiet high-speed AF function, as well as full
time manual focus capability.
This lens also features a Zoom Lock device to eliminate "Zoom Creep"
when the lens is tilted down. When the lens is set to the 50mm focal length,
it is remarkably compact and provides easy handling. The tripod mount
is composed of magnesium, to minimize total weight and also it is easy
to grip and carry the lens due to ergonomic design of the tripod mount.
Non-rotating front lens elements, due to rear focus mechanism make possible
the use of a custom bayonet "Petal-type Hood", which prevents
extraneous light from degrading the image quality. This mechanism also
allows the use of circular polarizing filters, since the front barrel
does not rotate during focusing or zooming.
