Canon 1D Mark IV review
The 1D Mk IV is one of the best DSLRs ever produced. As to whether it is better or worse than Nikon's D3s is too close to call without direct comparison testing between the two. It's fair to say, though, that both have their benefits and faults and on comparing their ISO performances on our colour chart, the 1D Mk IV doesn't control noise as well above 12,800 but it does have other strengths.
The power of this camera is immense and its ability to shoot full 16MP 14-bit Raw files at 10fps - while tracking a moving subject - is jaw-dropping. If I had the money to spare I'd buy this camera tomorrow, but realistically you need to be making serious money from your images to justify spending £4,000 on the body alone. However, with this camera you would certainly have a head start in producing good enough shots.