Finally, here are comparisons of the 100mm DOF to the 50mm DOF, all shot at f/8. Note that the first image, shot with the 5D at 100mm and cropped, has a much less DOF than the second, shot with the 50mm and cropped even more. Note also, that the third image, shot with the 30D with the 50mm and cropped, has essentially the same DOF as the 5D and 50mm. So, focal length counts a lot when figuring DOF, especially at closer distances! Sensor sizes don't count!