Shoot in the dark. That's essentially what you can do with the Canon 5D Mark III -- with a top sensitivity of ISO 102,400, what was once unfathomable could soon become an acceptable standard. While point-and-shoot manufacturers are adding WiFi and GPS, and tweaking algorithms in an effort to boost sensitivity beyond the 6400 mark, Canon and Nikon are making clear cases for a DSLR upgrade, by drastically improving image quality. The 5D Mark II had an e