Sigma's line of professionally oriented products is extensive. From the flagship SD1 DSLR to the fast prime and constant-aperture zoom lenses, Sigma makes a complete system designed from the ground up for professional photography. For example, the SD1's revolutionary sensor technology matches up perfectly with the 24-70mm ƒ/2.8 EX DG HSM and 70-200mm ƒ/2.8 EX DG OS HSM zooms and the 30mm ƒ/1.4 EX DC HSM and 85mm ƒ/1.4 EX DG HSM prime lenses. These lenses synergize with the Sigma SD1 to produce images with the finest sharpness, contrast and detail you can get, period. The sensor on any digital camera can only perform as well as the lens that's in front of it. The Sigma System doesn't compromise on image quality because you can't afford to either.