Have you ever wanted to know exactly how many times your shutter has fired? Invariably your images receive a filename partially based on a 4 digit number starting at 0001 and rolling over at 9999. How many times has it rolled over at 9999? Whilst I can’t speak for Canon users, on my Nikon’s I can go back to my external HDD (Hard Disk Drives) and laboriously search for DSC_9999.nef (.jpg) and work out there are say 12 of those thus the camera in question has fired at least 12,000 images. Time consuming and hardly accurate if you have deleted a few 9999 shots, or if you have backed up to DVD and deleted sets.
If you are familiar with EXIF tagging, at least on my Nikon’s, the total overall shutter count is recorded within each image. So how do you check that camera’s mileage?