In this Fine Art video tutorial you will learn how to replace focusing screens on Canon EOS cameras. The EOS 40D, like the EOS 5D and EOS 1 series of digital cameras has a user replaceable focusing screen. With the EOS 40D, you have the option of Ef D and the Ef S focusing screens. To replace the focusing screen, use the tool provided with kit supplied with the screen. The tool has a hook at one end and a spring loaded grip at the other end. Use the hook to lift the latch of the focusing screen chamber. This will reveal the installed screen. Remove the screen by gripping the tab with the tool and replace it with the new screen. Then with the tool lift the focusing screen chamber back till it clicks in to place.