• For use with smaller chip APS-c or 4/3 digital cameras only
• Compact size weighing 16 ounces and only 3.2 inches in length
• Two Aspherical glass elements offer correction for distortion
• SLD (Special Low Dispersion) glass & ELD (Extra Low Dispersion) glass element provides optimum color correction & sharpness
• Super Multi-Layer lens coating reduces flare & ghosting & assures high image quality throughout the entire zoom range
• Inner focusing system eliminates front lens rotation making the lens suitable for use of polarizing filters
• A minimum focusing distance of 8” & a maximum magnification factor of 1 to 3 make this excellent for up-close subjects
• A lens hood, front & rear lens caps and carrying case are included with the lens.
  

The popular Sigma 18-50mm f/2.8 EX DC Macro Lens has now been improved with closer focusing capabilities – as close as 7.9″ (20 cm) – and has a maximum magnification rating of 1:3, ideal for close-up photography. This lens is exclusively designed to suit the characteristics of digital SLR cameras. The characteristics of digital SLR cameras were taken into consideration when designing the lens power layout. The advanced lens design corrects various aberrations. This lens provides the utmost correction against lateral chromatic aberration which is a serious problem for digital SLR cameras.

This lens is also specially coated to get the best color balance with a digital camera, while also cutting down flare and ghost caused by reflections from the digital image sensor and lens. It has correction for vignetting and superior peripheral brightness is ensured. Ideal as a standard quality zoom lens with added macro capability, this lens provides an equivalent range of approx. 28-80mm when used with a Canon digital SLR camera.

DC lenses are exclusively designed for digital SLR cameras. The image circle (rear of lens) is made to match the smaller dimensions used for the image sensor on digital cameras. As a result these lenses are also more compact and lightweight, and are better matched to digital SLR cameras.

• EX lens series denotes excellence of engineering and new technology
• Large aperture of f/2.8 throughout the entire zoom range
• Correction for various types of aberration provided by one SLD (Special Low Dispersion) glass element and two aspherical lenses
• Super Multi Layer (SML) coating reduces flare and ghosting from which digital cameras tend to suffer

Reviews

Review of the Sigma 18-50mm DC f:2.8 EX Lens by TopicPoint.com

The Sigma 18-50mm F2.8 EX DC lens is a nice, light weight, bright lens. It serves well as a general-purpose lens, and its bright f/2.8 aperture is wonderful, especially given its compact size and light weight. The lens is sharp at f/8.0 to f/16 throughout its range, very good at f/5.6 and f/22, and usable at f/2.8 though rather soft. Remember, there may be sample variance, so since my tests were done only on one copy of the lens, it may not represent the performance of another unit of the lens. It has a good finish, a nice feel, and its price is reasonable for its performance level. Its most glaring omission is the lack of a depth of field scale.

Sigma 18-50mm F2.8 EX DC vs Carl Zeiss Planar 1.4/50 T*

It is not really a fair comparison to test a F2.8 zoom lens against one of the best prime lenses ever made for 35 mm cameras. At f/2.8, the Carl Zeiss Planar is already stopped down two stops compared to the Sigma zoom which is wide open at f/2.8. I was happy to see the Sigma perform as well as it did.

I’ve been used to (and spoiled by) Canon’s USM technology. One major concern for me was the focusing performance of this lens. It is not exactly USM-like but it is quite good, better than I expected. Reasonably fast and not very noisy due to the internal focusing design.

This test showed me that the lens is really usable at f/2.8 at all focal lengths. The fact that it does get even better stopped down is to be expected and doesn’t spoil the results wide open. At f/8, the Sigma 18-50 F2.8 performs almost like the best primes. I am very excited about this lens and I would give it a Highly Recommended in dpreview terms.

Lens Test: Sigma 18-50mm f/2.8 EX DC Macro by PopPhoto.com

For tabletop shooters who like to reach out from the camera position to reposition or otherwise manipulate their subject, this 1:3 macro is probably the closestfocusing lens in its class. In all, it’s a stellar performer, and significantly better by virtually all optical benchmarks than its predecessor, or, for that matter, competitors such as Nikon’s comparable 17-55mm f/2.8 ($1,200, street).

Links

Sigma 18-50 mm F2.8 EX DC Macro lens press release