Memory Cards for Digital Cameras - Compact Flash

CompactFlash memory cards for digital cameras were first specified and produced by SanDisk in 1994. There are two main subdivisions of CF cards with different physical sizes. Type I (3.3 mm thick) and the Type II (CF2) cards (5 mm thick). CompactFlash memory cards for digital cameras are among the oldest and most successful format of portable memory storage. CompactFlash memory cards are one of the most common types of digital camera memory. Most high-end digital cameras and all digital SLRs will work with CompactFlash memory cards.

Capacity

CompactFlash memory, as the name suggests, make use of flash memory formats. Older series of CompactFlash memory cards for digital cameras range from 128 MB of memory space to 1 GB of space. New card series provide memory space of up to 4 GB. While much of the older cards are no longer in production, they are still found widely off the web.

Transfer Speed

There are four families of transfer speeds for CompactFlash memory cards. These are the original CF, CF2.0, CF 3.0 and CF 4.0 standards. Naturally, the maximum transfer speeds of the cards increases with increasing number. Card speeds are given in 'x' ratings, e.g. 10x, 20x. This is the same 'x' rating system used for CD-ROMs. The 'x' rating indicates the transfer speed in multiples of 150 kB/s, for example, 10x will mean a maximum transfer speed of 1500 kB/s. The base value of 150 kB/s comes from the data rate of the earliest CD-ROMs.

CompactFlash memory cards also differ from other memory cards for digital cameras in that they have a controller chip in each card. This chip allows for higher transfer speed, although most cameras are unable to take advantage of this extra speed. To utilise this higher transfer speed, cameras require larger internal buffers. Only digital cameras such as DSLR have large enough buffers to be able to advantage of the high-speed feature.

Higher transfer speeds may not be significantly more useful for your camera; it does help to shorten the time it takes to move your files to another media. The fastest CompactFlash memory cards transfers with speeds up to 600x or 90 MB/s.

Compatibility

CompactFlash memory cards are among the most compatible of memory cards. They can be used by all DSLRs and a large range of other digital cameras. However, they usually do not fit in the card slots of very small digital cameras due to their larger card size. This is especially with new point-and-shoot digital cameras with emphasis on their small size. CompactFlash memory cards also do not work with Sony cameras, which have their own dedicated memory card series - Memory Stick.

Newer memory cards with higher capacity such as 4 GB or more uses a different file system (FAT32) from older cards (FAT12 or FAT16). Therefore, older camera models not running on FAT32 file system will not be able to access the memory cards correctly.

It used to dominate the market for flash memory, especially in the digital camera market. However, arrival of newer and smaller memory cards in the market has eroded its market share. This is especially so for point-and-shoot digital cameras. However, CompactFlash memory cards for digital cameras are still favoured for used with larger cameras like DSLRs for their larger capacity and faster transfer speed.

The larger design of CompactFlash memory cards means that its manufacturers can increase the capacity of their cards much faster than that of their competitiors. CompactFlash is relatively inexpensive, widely available and are compatible with most digital cameras. Therefore, CompactFlash remains as one of the most compeititive types of digital camera memory.