The Canon 5D Mark 3 has a full frame sensor with a resolution of 22.3 MP, one megapixel more than the Mark 2. It performs faster with its DIGIC 5+ processor and also shoots up to 6fps for capturing fast action. At 720p, it can shoot slow motion. Above all, the big selling point this DSLR has is its low light capabilities. The Mark 2 is already good in low light but the Canon 5D Mark 3 reaches new levels with its top ISO of 25600. In video mode, its top ISO is 12800, twice the top ISO of the Mark 2. Solidly built and with exciting new features, the Canon 5D Mark 3 is definitely worth the extra money if your shoot calls for it.