A type of camera lens, or to go really fast
If you have a fast lens on a cheap body, the camera body's AF drive system ... 
Well, if you don't have tires, it probably won't go very fast, but the engine .... For 
example low end models have one cross type sensor in the center... [DOC] [TLE] The 3 DSLR Lenses You Need (and 2 More You'll Crave) - Gizmodo [PAR] Aug 6, 2009 ...