Anyone who knows about camera lenses would instantly recognise the name Sigma, because not only is the company that manufactures the maximum number of lenses in the world, it is also one of the best. Sigma Lenses offer you incredible picture quality, ease of use, a variety in terms of exposure and focal lengths and all these at rates that will not burn through your life savings. Given that most of the Sigma lenses work well with Canon and Nikon cameras, there is a good demand for these lenses, globally.