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Sigma 50-500mm f/4-6.3 EX DG HSM and 180mm f/3.5 EX DG HSM lenses

Sigma is delivering on their February announcement of new lenses for digital SLRs. This time Sigma has released the details and full specifications of the Sigma 50-500mm f/4-6.3 EX DG HSM and the 180mm f/3.5 EX DG HSM lens. The 180mm lens will be available for Canon, Nikon and Sigma SLR cameras, while the 50-500mm lens will be available for Konica Minolta and Pentax too, albeit without HSM...

OVERVIEW

View all Sigma interchangeable lensesTelephoto Zoom Lens - Sigma  50-500mm f/4-6.3 EX DG HSM

High Magnification Ultra Telephoto Zoom Lens, with a 10x zoom ratio from 50mm to 500mm, optimized for digital SLR cameras.

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.

It is possible to reach 1000mm focal length by using the Sigma 2X Apo Tele Converter
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.

The APO lens corrects chromatic aberrations
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.

HSM (Hyper Sonic Motor)
The HSM models (the HSM is only available for AF Canon, Nikon and Sigma Mounts) provide quiet high-speed AF function, as well as full time manual focus capability.

Easy Operation and Handling
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.


Macro Lens - Sigma 180mm f/3.5 EX DG HSM

The new multi-layer lens coating reduces flare and ghost, which is a common problem with digital cameras. Two SLD (special low dispersion) glass elements ensure high optical performance for film SLR cameras as well as digital SLR cameras.

Taking pictures of small animals and insects can be difficult, because they often run or fly away, or can be dangerous or become aggressive if you approach them. Therefore it is advantageous to have a greater working distance between the camera and such subjects. Longer focal length lens can provide this greater distance, but most long lens do not focus close enough to provide a large image of small subjects. The tele-macro type lens solves this problem by producing a large, high quality image, up to life-size, while maintaining a long working distance. This can enable you to capture on film the world of photomicrography, without disturbing the subjects. The 180mm F3.5 EX DG MACRO lens has a very narrow field of view, and can allow very narrow depth-of-field for selective focus and less distracting backgrounds. This lens is most desirable for photographers who are serious about producing high quality images both of macro subjects at life-size reproduction, as well as normal telephotography.

Floating Inner Focusing System
The Floating Inner Focus System of the APO MACRO 180mm F3.5 EX DG HSM provides high quality optical performance and superior handling and stability. This system moves two lens groups within the lens, so the lens' physical length remains unchanged. This technique also maintains good correction for Spherical Aberration and Astigmatism and provides extremely high optical performance from infinity to 1:1 Macro.

Full-time Manual Focus with HSM
Macro photography requires precise focus adjustment. The HSM (Hyper Sonic Motor) feature is ideal for this purpose as it allows quick and precise manual focus, even in auto focus mode. Simply focus with HSM auto focus, then while partially depressing the shutter release, turn the manual focus ring until any desired focus adjustment is made. Then depress the shutter release fully to take the picture. It is not necessary to switch from AF to MF. When the shutter release is next depressed, the AF function will resume. Of course the AF function can be disabled altogether, and only MF used, if desired.

It is possible to use 1.4x or 2x Sigma Apo Tele Converters
Macro photography can be further enhanced by the 1.4x APO EX tele-converter, which allows the photographer to use the new SIGMA APO 180mm F3.5 MACRO lens as a 252mm F5 lens while maintaining auto focus function from infinity to 1.2m with Canon, Nikon and Sigma cameras. At distances closer than 1.2m the lens automatically switches to MF mode. When this lens and the 1.4x EX tele-converter are used with Minolta or Pentax cameras the lens must be focused manually. When used with the 2x EX tele-converter, the 180mm F3.5 lens becomes a 360mm F7 lens with manual focus function only, regardless of camera mount.

Use of SLD (Special Low Dispersion) glass
Image quality depends in part on color Aberration, which occurs due to differences in the wavelength (color) of light, causing the different colors to focus at different planes. SLD glass in the front optical group helps compensate for this phenomenon, and enables the lens to deliver images of high optical quality, having outstanding crispness and sharpness

Additional information: View all Sigma interchangeable lenses
May 20, 2005
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