Here's how: 1  Stand with your feet shoulder-width apart and knees bent slightly. 2  Lean forward, placing your hands just above your knees. 3  Round your back so that your chest is closed and your shoulders are curved forward.  Then arch your back so that your chest opens and your shoulders roll 1  back. Repeat several times.
Typically this count is between 100,000 and 300,000 shutter actuations, with the latter limit associated with the EOS-1D models. In fact, the Camera Shutter Life Expectancy Database is a really neat user-based site for DSLR models of several brands, including Canon.
My 1999 1.6 8v Astra has had 5 egr valves, and the car has a FULL vauxhall service history. The engine management light has come on again and the fault code is...you've guessed it. Ready for number 6. The last 4 valves have lasted JUST over 12 months before going.