Sigma EX DC Macro, designed to fit the APS-C sensor, includes elements to reduce distortion, not only limited to SLD (Special Low Dispersion) and ELD (Extra Low Dispersion) glass for increased sharpness and optimal color correction. This 18 mm - 50 mm f/2.8 lens is compatible with 1.5x/1.6x digital SLR cameras and maintains a constant large aperture. Additionally, this Sigma EX DC Macro is a good lens for general use, with a wide focal range, including a short 11-inch minimum focal distance. A well-balanced lens, this Sigma EX DC Macro is 3.31-inches in length, 2.91-inches in diameter, and weighs just 15.7 oz. The Sigma camera lens for Canon is relatively quiet when it comes to the autofocus and the accuracy of AF is average. Helpful in this 18 mm - 50 mm f/2.8 lens is the internally focusing lens and non-rotating front element, so the length of the lens stays constant. Professional photographers or even amateurs will find this Sigma camera lens for Canon a useful addition to the APS-C sensor DSLR camera.