They say in photography that the better the glass, the better the picture. That's true and it is the single biggest reason why photographers are broke and their lenses are big. However, not all lenses need to be honking huge to be good and most importantly, fun to take pictures with.
The SIGMA 10-20mm F4-5.6 EX DC HSM is a wide angle ZOOM lens built for Digital SLR Cameras. This particular one works with Nikon DSLR's and is a great match for my Nikon D50. It is also unique because unlike most wide angle lenses that have a 12-24mm focal range, this one is even wider at 10-20mm. I chose this lens because based on all the reviews of it from the Digital Photography Sites, it was not only a great value at half the price of the NIKON unit, but it also went wider. In fact, it's the widest angle lens on the market for DSLR.
A wide angle lens, unlike a "Fish Eye" lens, does not distort the picture to give you a fish eye effect. It allows you to pull back without actually moving back. For example, if you're out in crowded spaces where you want to take pictures, a conventional lens would have you quite far back, as people move back and forth in front of your shot. Instead of spending the time to compose your shot, you are concentrating on when the next person is going to stand in front of your camera and ruin your shot. Let me illustrate with the following pictures...
The above is a picture taken using my NIKON 18-70mm DX ED lens. I'm taking the shot at 18mm and I'm about 5 feet away from the bikes.
The shot above is taken the same distance away, from the same spot. The only difference is that I'm now using the SIGMA 10-20mm F4-5.6 EX DC HSM at 10mm. Huge difference huh? The lens is an absolute life saver in places where you just can't pull back far enough to take the shot. This will probably be my lens of choice for any trade shows or parties I go to simply because there is just not enough room to get a good shot using a more conventional lens like my NIKON 18-70mm. Especially when it is super crowded.
The picture used in my Blue Fur PHO post could have easily included everyone had a wide angle lens like this one been used. There wasn't very much room in the restaurant so it was tough for any conventional fixed lens camera to be able to get the shot. This is a great lens that's an absolute must have for any photographer that shoots portraits or in crowded environments. That and the Nikon 18-200mm DX VR that I'll be playing with soon. I'm not a pro photographer by any means, but I know that this was money well spent based on the results. I know that I'll be able to take many great pictures without worrying about someone walking in front of my shot.