Always so insightful! Very well structured, well documented, easy to access! This is the third in the series that I bought after the 400D and 450D! It is a great alternative to the manual supplied with the device, it enables progress, to go further, he debunks some functions may be too succinctly described in the official guide. It accompanies the user on the EOS universe by transverse section, such additional to objective, photo processing, filing, accessories, bibliography ... It has even courses a little more "masterful", light management, blurring, cropping, ...! Its price eventually convince his strong interest! If you only buy one, it will be one!