Digital Camera Memory

Analog cameras use film to both record and store a photographic image. Digital cameras use separate components to perform these functions. The image is captured by the image sensor, and then the image is stored in some sort of digital camera memory device. In this article we will explore the various storage devices that are available.

Removable and fixed storage

The very first differentiating factor is whether or not the storage device can be removed from the camera and another one plugged in. Original digital cameras, as well as some current but very inexpensive cameras, use fixed storage that can't be removed or increased. This limits the number of photographs that you can take without having to download or erase them to make room for more.

Any camera worth its salt uses some sort of removable storage media. While most models have some type of digital camera memory card, others use small hard disks, CDs, and even floppy disks. No matter which method is used, the purpose of removable media is to let you remove one storage device when it's full and insert another so you can keep on taking pictures until you run out of spare digital camera memory devices.

Storage capacity limits

The number of images that you can store in a camera depends upon a number of variables including the capacity of the storage device in megabytes, the resolution at which the pictures are taken, and the amount of compression used.

Think of storage capacity as if it were numbers of rolls of film. If you shoot 10 rolls of film at an event, and you take your digital camera this time, then you need to have the capacity to store the equivalent of 10 rolls of film in removable digital camera memory. Like spare rolls of film, extra removable memory let's you keep on shooting until you run out of room.

Flash card storage

Flash memory cards are small, inexpensive digital camera memory devices, similar to the RAM chips used inside your computer except they do not lose the information that they hold when the power is turned off. In fact, flash memory requires no power at all. Saved images may be stored indefinitely without any power being supplied. Flash memory card is a generic term for removable memory storage devices with brand names such as PC Cards, CompactFlash, SmartMedia, MemorySticks, and xD-Picture Cards.

Since flash memory cards take up very little space and are very rugged, you can carry lots of them around with you to ensure that you always have enough storage space available to archive any images that you take. Be careful of one "gotcha" though. Flash memory cards come in a wide assortment of formats and they are not interchangeable with other formats. So be sure that you buy the exact type of card that your camera requires.

Different camera manufacturers support different memory methodologies. It is too soon to tell if there will be a shakeout and one format will prevail. Here is a summary of the features of each card type.

PC Cards (ATA)

Although PC Cards have the highest storage capabilities, they are quite large compared to other storage devices and as such, have found their way mostly into the professional-level digital cameras which tend to be more bulky than the other types.

CompactFlash cards

CompactFlash cards are the most technically advanced of all the storage formats. There are two different categories of cards named appropriately, CompactFlash (CF) or CompactFlash Type I (CF-I) and CompactFlash Type II (CF-II). If a camera specifies CompactFlash, without any number, then it is CF-I.

Essentially, the only difference between the two categories is that the CF-I and their corresponding camera insertion slots are 3.3 mm thick, while the CF-II cards are 5 mm thick.

SmartMedia cards

SmartMedia cards are smaller than CompactFlash cards and have considerably less storage capacity. They are waning in popularity.

Sony Memory Sticks

Sony memory sticks are proprietary storage devices used exclusively in Sony cameras. They are available in sizes up to 32mb.

XD-Picture Cards

The XD-Picture Card™ is the smallest of all memory cards. It is used in very small and miniature cameras. It was developed jointly by Fuji and Olympus as a replacement for the SmartMedia card.

Hard disk storage

The biggest problem with a digital camera memory card is the limited storage capacity. This is a real problem if you are shooting high resolution photographs which require more pixels and thus, more storage or if you are shooting a lot of pictures. Miniature hard disk storage is an outstanding solution to these problems.

When most people think of hard disks they immediately picture that big, clunky disk drive that's inside of their PC. Nothing could be farther form the truth. The Hitachi Microdrive hard disk drives can be plugged directly into a Type II CompactFlash slot on a digital camera or flash card reader. These drives are so inexpensive that you should seriously consider getting one if you camera has a CF-II slot.

In Summary

With all of the memory options available it is difficult to decide which one is best for you. If it were my money, I'd opt for a camera with a CF-II slot. That way I could use a high-end digital camera memory card and step up to a compact hard drive when the time came.