Sigma

Advantages Huge range of features, good value.
Disadvantages Focusing system, limited system support.

...Anyone looking for a serious auto focus 35mm SLR should take a serious look at the Sigma SA-5 QD. While a camera from one of the "big four" might be a more obvious choice, this feature packed offering from the renowned lens manufacturer has plenty to offer. For a start there are no less than five exposure modes, starting with the fully automatic * setting that turns the SA-5 into a point and shoot camera that's as simple to use as a compact. There's also the programmed AE mode that still leaves most of the work to the camera, while more serious experienced photographers will welcome the choice of aperture priority, shutter priority and fully manual modes that give them full control of their photography. Further control comes courtesy of three AF modes. AF-S only allows the shutter to trip when the subject is in focus to ensure... Read review

Advantages excellent image quality, sturdy build, great price
Disadvantages relatively slow aperture, slight softness in mid-range of zoom.

...The Sigma 10-20mm EX lens is a low-to-mid priced lens, aimed at the amateur/enthusiast market and available in the usual Canon and Nikon mounts. I own the Canon-fit, so all information contained in this review is in relation to that lens. For anyone interested in landscape photography, a wide-angle lens is a must-have piece of equipment. With standard kit lenses generally weighing in at the 18mm range at their widest zoom setting, you will be astonished at what the extra 10mm can provide you with. With this extra range of view, it's also an ideal lens for architectural photography and can make even small interiors appear almost cavernous at times. The lens itself is solidly-built, as you would expect given the pricetag and the Sigma EX badge - a mark of quality on Sigma's lens range - and the weight is satisfying. It may feel... Read review

Advantages Crips, sharp, contrast full images; silent focusing; f/2.8 apature
Disadvantages no image stabiliser

...This listing on ciao doesn't have a model number for focal length so I am going to review the Sigma APO 150mm f/2.8 Macro lens Before I purchase products I do extensive research on them; I read magazines and scour the internet looking for absolutely every bit of information I can before I buy. When deciding on buying this lens it was no differentl; I must have ready 2-3 magazines reviews and a dozen internet review sites before deciding which macro lens to purchase The reasearch I conducted showed that there two VERY good macro lenses available; the Sigma 150mm f2.8 and the Canon 100mm f/2.8. After investigating these two lenses further I found that the Canon was contiously rated as the best possible Macro lens (in the price category - there are Canon L series macro lenses which would cost 4 times the price) but the Sigma... Read review