Published in AustralianIT, July 15 2003

REMOVABLE storage is underpinning the success of digital cameras.

Being able to download pictures without needing a PC on hand has given digital cameras the same unlimited capacity as film cameras, with the added advantage that a flash memory card takes up much less space in your luggage.

You can also get conventional prints in photo processing stores as well as taking advantage of digital distribution.

All kinds of storage options have been explored, from floppy disks to PC cards to 3in CD-Rs.

The most enduring options are based on compact flash memory, which has low power requirements, high storage capacities and is robust enough to bounce around in a shirt pocket while you wait for your subjects to look in the right direction.

Most current digital camera models offer one of two options -- Secure Digital (SD) cards or Memory Stick. The former was created in 2000 by a consortium of industry players as a successor to earlier compact flash systems.

The latter was originally developed in 1998 by Sony for use across its electronics lines, but has since been adopted by a number of other manufacturers, including SanDisk.

Sony's earlier appearance in the market gave it an early lead, but SD cards have been gaining rapidly.

Analyst IDC predicts SD will have twice the market share of any other format by 2006.

Typically, both cards and sticks are offered in 8, 16, 32, 64, 128 and 256MB formats. Capacities are, however, increasing rapidly. Sony already offers a 1GB Memory Stick PRO Model, and has outlined plans for 32GB. In January, Panasonic demonstrated a 1GB SD card.

What's less likely to change is the size of removable storage devices. Sony maintained the same dimensions (50 by 21 by 2.8mm) for its Memory Stick Pro line as for earlier models.

This suggests the format is already acceptably small (although it also assists with backward compatibility). In the case of stamp-sized SD cards, if they became any smaller they'd be impossibly fiddly and difficult to use.

Still, a thumbnail-sized miniSD card for use in mobile phones has been demonstrated.