martinfisherphoto wrote:
Up to 9,999 and then roles pack to 1. How do you find the true count?????
You are confusing the file numbering system with shutter count. Those are two very different things.
File numbering is sequential up to 9999, as you say... then it rolls over and restarts at 1 again. (Some older cameras only went to 999... and some cameras allow the user to choose whether file number remains consecutive or resets each time a new memory card is installed or some other options).
Shutter count is a continuous sequence of actuations or "clicks" throughout the lifetime of the camera. It is sort of like car mileage.
Shutter count may or may not tell you very much. Early on (late 1990s), it was a big issue because many manufacturers were using shutter (and other) mechanisms the simply adapted from their film cameras. It turned out that digital users shots 4X, 5X... even 10X more images than film shooters! After all, "digital is free"! (Which is not really true... although there isn't the ongoing cost of buying film and paying to get each roll processed reminding and constraining the user, the way there was with film cameras.)
Shutters in some early digital were only good for 15,000 or 20,000 actuations. Olympus was making some great cameras that appealed to pro users who were just starting to get their feet wet with digital... but were wearing out shutters (and other mechanisms) in 6 months or less! Oly ended up having to replace a lot of worn out parts under warranty... sometimes twice! That HAD to be expensive! All manufacturers took heed and redesigned their shutters (and other mechanisms) for increased durability... so that the cameras might be expected to live for 4 or 5 years (or at least until the warranty expires!
)
Canon's more entry level Rebel series (xxxD and xxxxD models outside N. America) are typically rated for 75,000 actuations. Their mid-grade models like 80D and 6D are rated for 100,000 clicks. And their more upscale models like 5DIII/IV, original 7D might be expected to achieve a 150,000 shutter count, while higher speed models like older 1D series and 7DII are rated for 200K, and ultra high end models for 300K to 450K.
In truth these are mere estimates that were calculated in advance by engineers designing the components. I know of some 5D-serises that have exceeded a million clicks and are still going.
Shutter count is a "mean time between failure" figure... an estimated
average life expectancy that's related to the shutter, but actually might apply to all components of the camera much the way mileage is used for automobiles. There is no warranty directly associated with shutter count, though, the way there often is with cars. You might buy a Ford Focus with a 3 year, 36,000 mile warranty (whichever comes first)... but you get a 1 year or two year or whatever with cameras... there's no mention of "clicks" at all.
Plus, not all clicks are equal. What I mean by that is a camera with very low shutter count that's been used for a lot of video might actually have far more hours of use on its components, compared to a camera that's been used exclusively to make still images. Videos might average 30 seconds of continuous power-on status for the camera... while a shutter actuation might average 1/250 of a second. If those averages were accurate, in some ways TWO videos would be equal to 7500 stills! In other words, the camera's "power on" status would be the same with 20 videos versus 75000 still images!
This is a little like wear and tear on an automobile not being fully explained by mileage either... A car that's driven in town, for shorter trips in stop and go traffic will wear out in fewer miles than a car that's mostly used for highway cruising.