Hi I own a dirt racing website, and this year I want to get into photography. I have a budget of $400-$600 and the camera's I am considering are the Nikon D5000, D3100 and the D60. I have come close to purchasing a camera multiple times on ebay but I am scared to pull the trigger because you can read good and bad about all of them. I am looking for the best camera to take speed shots, in partial to full light.