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 color balance.

This lens uses four pieces of SLD (the special low dispersion) glass for excellent correction of color aberration. A zoom lock switch eliminates ‘zoom creep’ during transportation, a convenient addition when traveling. The HSM（Hyper Sonic Motor） models provide quiet high-speed AF function, as well as full-time manual focus capability., The rear focus mechanism produces a non-rotating front lens element which accepts a bayonet “Petal-type Hood”, which prevents extraneous light from degrading the image quality.

By adding an APO teleconverter (sold separately), you can use this lens as a 140-700mm F7.3-8.8 MF ultra-telephoto zoom lens with a 1.4X EX teleconverter, or as a 200-1000mm F10.4-12.6 MF ultra-telephoto zoom lens with a 2X teleconverter.（Teleconverters can be used in 100mm – 500mm focal length range）

High Magnification Zoom Lens with a 10x zoom ratio. Optimized for digital SLR cameras.

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.

Reduction of Flare and Ghosting
The advanced optical design is optimized for digital SLR cameras. In addition, the new super coating on each glass surface produces superb color rendition, while reducing flare and ghosting.

SLD glass for superior optical performance
This lens uses four pieces of SLD (the special low dispersion) glass for excellent correction of color aberration throughout the entire zoom range.

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

APO Tele-Converter EX (optional)
By adding an APO teleconverter (sold separately), you can use this lens as a 140-700mm f/7.3-8.8 MF ultra-telephoto zoom lens with a 1.4X EX teleconverter, or as a 200-1000mm f/10.4-12.6 MF ultra-telephoto zoom lens with a 2X teleconverter.(Teleconverters can be used in 100mm – 500mm focal length range)

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.

Reviews

Sigma 50-500mm f/4-6.3 EX DG HSM Lens Review by the-digital-picture.com

Any 10x SLR zoom lens (50mm x10 = 500mm) is going to be attractive, but one that ends with a 500mm focal length is going to get an especially high amount of attention. Sigma 50-500mm f/4-6.3 EX DG HSM Lens, for this reason, but not for this reason alone, is a very popular lens. The fact that Canon’s longest zoom ends at 400mm and costs much more increases the demand for this lens.

Sigma 50-500mm f/4-6.3 EX DG APO HSM Interchangeable Lens Review by ephotozine.com

The positive points of the Sigma 50-500mm EX DG HSM are:

• Good build quality
• Excellent focal range
• Well controlled distortion and CA
• Good value for money.

The negative points are:

• A bit of a lump to carry all day.
• Slightly softer than shorter zooms (but not much!)
• Only a single socket on the tripod mount.