Removable storage devices enable you to take as many shots as the device will hold, pop it out, pop in another and keep on shooting. It’s like carrying extra film for your analog camera. You can keep shooting until you run out of “rolls”.
How many shots you can store is a factor of the capacity (number of Megabytes) of the storage device, the image resolution and the type of compression being used.
This is an important number to know because when you reach the capacity limit you’re either going to have to remove the device and slip in another, download the images to a computer or erase some of the images.
It’s easier to choose storage device capacity if you think in terms of “rolls of film”. If you normally shoot 10 rolls of 24 exposure when you’re off on vacation, then you need enough removable storage to hold 240 images at whatever resolution
you’ll be shooting. Storage is cheap so it’s better to have and not need than to need and not have.
There are different types of removable storage technologies available and the one that you use is dictated by what your particular camera supports.
Removable Flash Memory cards use RAM chips which are similar to the ones found in computers except they do not have to stay powered up to store your images.
While many digital cameras us the standard PC Card (PCMCIA)interface for their flash memory, some manufacturers are introducing proprietary formats which restrict the type and brand of card which can be used.
Common flash memory devices include PC Cards, CompactFlash, SmartMedia, Sony MemorySticks and xD-Picture Cards.
PC Cards have the most storage capacity but their large physical size restricts their use only to big-frame cameras.
CompactFlash (CF) cards are the most widely used storage device among the entries in the consumer camera market. There are two types of CF cards. CompactFlash cards with slots that are 3.3 mm thick are known as CompactFlash (CF) or CompactFlash Type I (CF-I). If the slot is 5mm thick then it is a CompactFlash
Type II (CF-II). CF-II is gaining in popularity.
SmartMedia cards are smaller than CF cards and do not have as much storage capacity.
Sony Memory Sticks are used mostly in Sony digital cameras although some other brands do support them.
xD-Picture Cards are the tiniest of the removable storage devices and are used in miniature digital cameras. They are designed as a replacement for the larger SmartMedia card.
It’s important to know what type pf storage device a camera uses before you buy it. That way you can make intelligent decisions concerning the ongoing costs of storage and choose a camera which most closely matches your needs.