CF Card Type I
Inside a CF Card
Jenny Altschuler's Online Virtual Project
Altschuler's After Dark: Sojourns in the Night project, curated from the South African Centre for Photography's facebook site is now closed for submission. The project will be presented as a digital slide sequence at the Room Party 4th August at the BIOCAFE 32 Kloof St. Gardens, the venue for the Talking Images LIVE EXHIBITIONS.
Jenny Altschuler's online visual project on the SA Centre for Photography's facebook site. http://www.facebook.com/event.php?eid=12580989727
Understanding CF (CompactFlash) Cards
In the ever expanding world of digital photography, Data Cards are as indicative of generational progress as pixel counts are on sensors. CF cards, the main card type (there are 22 types of data cards for various camera brands) for professional cameras, have leapt forward in recent years, increasing in size and speed every few months. The technology that drives them has become so durable and stable that it is set to contend with conventional manganese ferrite hard discs in computers.
It's important though to differentiate between the three standards of CF card, Type I, Type II (also known as Micro Drive) and Type III. The first visible difference is the thicker width, Type I being 3.3mm and Type II 5mm. The vast majority of Type II cards are in fact miniature hard drives, with only a few exceptions being solid state flash drives. Type I is the most successful of the three specifications. Type III as a standard hasn't realy taken off with manufacturers. It is large and doesn't offer sufficient benifit for the extra size. It's dimensions are 85.6mm x 54.0mm x 10.5mm, which makes it three times as thick as Type I Cards. With the theoretical maximum size that Type I cards can reach being 137Gb, there is quite a bit of life left in the format under the current Version 4.1 of the standard.
The reason for the success of Type I (solid state) is a clear advantage of the medium. Solid state drives require no start up time (time it takes for the spinning disc to get up to functional speed) and faster random access time, as there is no Read/Write head. They also require less power and generate much less heat as a result. Lack of moving parts almost eliminates the risk of mechanical failure, though any storage medium does have limited numbers of erase/write cycles before a particular "sector" can no longer be written. Memory specifications generally allow 10,000 to 1,000,000 write cycles. Typically the controller in a CompactFlash attempts to prevent premature wearout of a sector by mapping the writes to various other sectors in the card - a process referred to as wear levelling. Cards can continue to function reliably for some time after the first sectors become unuseable.
By formatting your card, you are specifying through the camera what format the card will be receiving it's data in, for the camera to read write. Most cameras use the FAT 12, 16 or 32 system, widely used for personal computers. It is however best to format the card through the camera that it's being used in and not your computer. Most modern camera's claim to be Fat 32 compatible. It is usefull to note that Cards can be formated top any file system avaible for other applications, such as PDA's.
Speed & Capacity
The first cards that appeared on the market in 1994, offered a whopping 2, 4, 8, 16, 32 and 64Mb capacity. The increase in potential has steadily increased with new standards being introduced every few months. The current top benchmark of readily available cards offer up to 64Gb of storage space.
Card speed is ussualy specified in times ratings, i.e 8x, 20x, 133x ect. (the same system as is used for CD Roms), where the number of in front of the x, when mulitplied by 150 kB/s gives the speed of the card (for example 8 x = 1.2 Mb/s, 20x = 3 Mb/s). More expensive high speed cards can reach up to 30 Mb/s, which is a significant improvement in performance for professional requirements.