Depending on how many megapixels each photograph includes, a one-gigabyte memory card can carry between 13 and 715 photographs at once. A card can contain more compressed files than uncompressed raw pictures for simpler storage. If each photograph is four megapixels, a one-gigabyte memory card may carry 715 compressed picture files. The same card can carry 13 raw photographs at a resolution of 22 megapixels each.
A one-gigabyte memory card from Kodak carries 260 six-megapixel photos and 45 16-megapixel photos. Sandisk cards may hold up to 71 raw, unprocessed photographs, each at a resolution of four megapixels. In compressed form, the same capacity may hold up to 715 four-megapixel images.
The size of each saved file determines the difference in memory storage. A compressed four-megapixel snapshot uses 1.2 megabytes of memory, whereas a raw photograph with the same megapixels demands 12 megabytes. More photographs can theoretically be kept on a portable drive if it has more memory.
The resolution of a photograph is measured in megapixels, abbreviated as MP in digital camera specifications. A megapixel is the smallest individual element of a photograph, and a pixel is the smallest individual element of an image. A photograph with a resolution of 10 megapixels has a better resolution than one with a resolution of five megapixels.