Thus to convert the image number to the number of shots taken we need to do the following: A twist is that looking at one of the early images I took with this camera is that the folder numbers start at 100 rather than 0. The folders each hold 100 files so the first 3 digits increment once every 100 images to reflect the new folder number while the last 4 digits increase to 9999 then rollover to 0. Under DCIM there are two folders at present: 291CANON and 292CANON. I then realised that the first 3 digits are in fact the folder number on the memory card. That makes more sense – the last image was IMG_9222.JPG. One EXIF data tool reports the number as 292-9222.
On my 10D, it shows 2929222 approaching 3 million shots which is clearly wrong. The number of shutter actuations on older Canon cameras is encoded in the 'Image Number’.
