Dear Hank, If you want to improve the quality of the student's work make them pay $ 1 every time they press the shutter release. Even if it is just testing out or fooling around. If your country has $ 1 coins make the student drop a coin into a deep glass jar so that it makes a noise. Do not give the money back to the students. This is the same as sending someone out to hunt bear with a loaded .54 Hawken rifle. It means they do it right first time. Uncle Dick