Sigma EX

Advantages Superb design, value for money and professional results.
Disadvantages None

...Sigma EX 12-24mm F4.5-5,6 DG Nikon fit AF D. This a great wide-angle zoom lens offering professional performance, results and is a joy to use. It is suitable for both digital SLR's and 35mm Film cameras and focusing can be used manually or autofocus. This my first Sigma lens as I own only quality Nikon lenses so I was unsure at first about purchasing a brand and lens unknown to me. Any doubts or fears about quality were put to rest as soon as I took the lens out of it's box. It is as well crafted as any Nikon lens and a truly remarkable piece of design. It has an unusual appearance as instead of the usual glass flat surface lens it has a "bobble" or "ball" of glass which has a very alien look to it. I'm still not used to this and I feel that as it is sticking out so much that it may be a bit vulnerable to potential damage... Read review

Advantages value for money (compared to pro level), build quality,
Disadvantages makes you think your a pro, but by its nature, proves you otherwise.

...This sigma lens is often a favourite starting point for digital SLR users (single lens reflex) looking to upgrade the 'kit' package they bought on impulse in the January sales. "I know, I've got a million pix of my children and cat, now I'll photograph flowers and insects with a macro lens, whatever that is". Don't kid yourself; the whole idea of this lens is to get close-up and personel with your subject matter (insects and flowers being two of my favs). If your looking for a mid-sized telephoto lens just to add to your camera bag, go and by a mid-sized zoom lens. Macro photography is not for the faint-hearted. It requires patience, skill and an understanding beyond that of the family photo album. But the rewards are excellent. With a good, solid build quality and good optics; it is worth buying if you can't afford a pro... 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