The essential difference between the two and visible cameras is the case. While the 400D has a very compact plastic housing, the EOS 40D comes with a voluminous, weather resistant housing therefore of a robust magnesium alloy. It positions itself as a camera for bigger hands and can deal with difficult weather conditions, without being damaged.
From the pictures fro both cameras are on the same level, because they use the same 10-megapixel image sensor. Technically used the EOS 400D a Digic II image processor, while the EOS 40D builds on the successor processor Digic III. Both cameras have an ultrasonic mechanism is cleaned with the switching on of the image sensor. The EOS 40D has an alternative raw format and trump in the speed sequential shots on. With a single battery charge provides the EOS 40D not infrequently more than 1,000 photographs, the EOS 400D needs at least fit in half, since it uses a smaller battery.
But was for my transition to the EOS 40D ultimately better ergonomics in the operation of the rash. In the small EOS 400D of space for operating elements is rare. This leads, in my view to an overall less practical and intuitive operation. Here, the EOS 40D has the nose clear with their dial on the back forward. I hoped from the EOS 40D a more comfortable operation, but I never thought that the differences are SO big. While I was one or the other setting kept forgetting the EOS 400D, I use the EOS 40D is absolutely intuitive after a first, short training.
My opinion: The EOS 400D is a compact entry-level camera with numerous features and an unbeatable image quality. However, the EOS 40D goes a step further and offers an excellent, robust and intuitive body, which has no equal. When it comes to speed and with some other technical features it has the edge. For an ambitious and creative Vielfotografierer the charge in the EOS 40D is worthwhile in any case.
