Originally posted by Wildnsyko No where does it say that if you put in a card with "X"gb it will read this. Being a noob that I am, I'm used to a digital telling me I've shot "X" number.
Something you'll have to get used to in the current state of digital photography is all the imprecision. The numbers are just estimates.
For film a straight counter makes sense, because there's a fixed number of pictures already exposed, and remaining on the roll. It's pure physics.
For digital there are several different pieces of technology at work that make it much more difficult to be precise. When the camera takes a picture, it stores it on an SD card that is using a PC filesystem. A computer can then access files on the card directly, as well as store/delete/etc any files it wants. In playback mode, it's possible for a camera to determine how many files are stored on the card quickly; however, a computer could have manipulated them at any time, so the only way to know which files are actual, readable pictures that have been taken by the camera is to examine each one individually. This would take a relatively long time on a modern high-capacity card, so it's not worth the effort just to create a "pictures taken" counter. When you consider that you can protect individual pictures from being deleted, and delete others at any time, the whole meaning of "pictures taken" gets a bit fuzzy: pictures taken when?
It's more useful to know how many pictures you can take before you have to change cards or delete some. Unfortunately, this is only an estimate too. The reason is that the pictures stored on the card are compressed, and the resulting size of each picture file depends on the mathematical nature of the image and how much the compression algorithm can do to make it smaller. Each picture therefore has a different size, and since the limit of the storage system (SD card) is total size rather than number of files, the "remaining pictures" counter can only be a best guess of how many average-sized pictures would fit in the space left on the card.
So that's the number most cameras show.
There are also several options for how pictures are saved that will change the average number that will fit on the card, so there's no simple answer for "xGB or greater will show 999". E.g. RAW+ DNG 10M *** format takes the most space and will require the largest card before showing 999 when the card is empty, while JPEG 2M * format takes the least space and will show 999 even on small cards. If there's anything else on the card taking up sufficient space, even if it's not picture data, then naturally the number will be under 999. Etc.
Hope this helps explain why, even if the answer's not terribly reassuring...