My review of the 1D Mark IV is a culmination of over two years of proud ownership and experience. Before I dive in though, I must say that it doesn't seem appropriate to write a review about the Canon 1D Mark IV without having first given a nod of respect to the important heritage of the 1D series digital cameras. All of them have a nearly impeccable reputation amongst the most demanding photographers in their (relatively) short 21 year history. Mostly, this is due to the fact that these same photographers have worked in the most demanding of all situations and climates. Sometimes even life and death situations. And when the reliability of your gear is that important, photographers have consistently reached out for Canon's 1D DSLR's to get the job done. My own personal photography experience has never been as important as life and death, yet the expectations I have of my gear, like many other photographers, are still very high. And when I need a camera to perform better, more consistently, and with the greatest of fluidity, I find that it's nearly impossible to find better cameras than the 1D series for those demands. Therefore it's my assessment that the numero uno in Canon's naming convention isn't just mere coincidence. It stands for something. They truly are amongst the best cameras that you will ever use.