Quick Photography Tip
Keep an eye on the light. It is constantly changing
Whether you realize it or not,chances are you've encountered a memory card in one form or other. Virtually every MP3 player,digital cameras and PDA ships with a built-in memory card slot to ramp up storage capacity. To cut a long story short think of a memory card as the equivalent of a hard drive for your camera or cellphone.
Not only these cards are used by flash gordon but because their data memory is changed by a sudden flash of voltage. Flash memory is a solid-state storage technology that allows data to be stored in electronic format. Unlike hard drives which are mechanical in nature and consists of moving parts,Flash-based memory does not consist of any moving parts. The advantage of having a flash based memory storage solution is that its robust and largely free from the problems associated with mechanical storage devices.
But downside of these cards are limited transfer speeds when compared to mechanical storage devices. The other drawback is storage capacity. These cards cannot store as much as their mechanical counterparts.
Having said that,the robust nature of these cards makes them well-suited for portable devices such as MP3 players digital cameras and PDAs-comes in handy because all of these devices are carried around extensively by users and are subject to intense wear and tear.
Lets take a loot at the variants available in the market:
Compact Flash Memory cards
Contrary to what the name suggests. Compact flash cards are not exactly compact. In fact cards are clunkier than every other memory card in the market. Developed by sandisk and introduced in 1994,compact flash cards (also known as CF cards) are predominantly used in digital cameras. Because of faster transfer speeds and support for higher capacities,compactflash offer high transfer rates by utilizing the memory controller chip it houses.
The other thing is digital cameras are larger and can accommodate these cards as opposed to MP3 players and PDAs. While not all cameras or devices can take advantage of the controller chip,high-end devices like digital SLR cameras benefit enormously from higher transfer rates. These camera come with advanced internal buffers that when coupled with the memory controller lead to high transfer rates.
There are two kinds of CF cards - Type I and Type II cards typically allow higher storage capacities but are also physically thicker. When buying a CF card,it is important that you check which type of CF card your device supports. If you are in the market looking for CF cards,capacities will range from 64MB to a maximum of 4GB. The most common cards come in 128,256 and 512MB and offer good value per MB of data stored. As we go above the 512MB mark,this equation skews because the cost of producing a higher-capacity CF card multiplies exponentially.
The write speed of the CF card is the speed at which it records data on the card. The read speed is the speed at which data can be read from the card - or to put it another way,the speed at which data can be transferred from the card to another device.
Speed is often given as a multiplier such as 4x,24x,40x and 80x. There is no indication what 1x represents,but its generally defined as a write speed of 150 kilobytes of data per second (KBps). 4x cards are rare these days,12x is about the slowest you see and 80x the fastest. An 80x card should be able to write at a speed of 12KBps,a 40x at 6MBps and a 20x at 3 MBps. The read speeds are usually similar to the write speeds.
SD - Secure Digital Cards
Unlike CF cards,secure digital cards are much smaller. Designed and developed by toshiba and matsushita,these are meant primarily for mobile phones and other compact devices where space is an issue. Though these cards are identical to multimedia cards,SD cards are popular because it offers an additional feature in the form of a built-in-encryption to safeguard data - hence the name 'secure digital card' coupled with the security is its compact size - good enough reason for its soaring popularity. This in spite of the fact that it is a bit more expensive than other formats. SD cards are now available in capacities between 16MB and 1GB. An SD memory card typically measures 32x24x2 mm and weighs approxomately 2 grams.
The memory stick is a proprietary storage standard that was introduced by Sony in 1998. These cards flash based memory storage device was designed to store still digital images,video,music files and other type of electronic data. when launched a memory stick was almost twice as long as a standard multimedia card (MMC). While a later format (Memory stick duo)is about half the weight of its predecessor and is backward-compatible if used with an adapter. The latest in memory stick technology is the memory stick pro,which supports higher speeds and capacities (256 MB and above ). Sony tied up with the flash memory card giant Sandisk to launch the new memory stickduo. A still later development lineup is the memory stick duo pro which supports higher capacities while retaining the small footprint of the original duo.
Sony provides its own version of security called magic Gate. A massive irritant is the fact that any content written on the memory stick using the magic gate software cannot be copied or transferred to other computers or devices. Magic Gate is sony's proprietary data encryption and authentication technology specifically made for their storage formats,including the memory stick duo pro.
Currently you can buy memory sticks with capacities ranging from 128MB to 512MB. you need to be aware of the exact type of memory stick required for your device because the multiple formats and revisions in the memory stick family makes it far too easy to confuse one with the other.
Multimedia Cards (MMC)
Very similar to the SD cards the MMC is a cheaper alternative commonly used in cell phones. The MMc standard was introduced in 1997 by a joint effort from sandisk and siemens. These stamp-sized flash based media cards are based on the same technology as SD cards but do not carry the security aspect that is specific to SD cards.
These cards fit into regular SD card slots but not vice versa. MMc arent as fast as SD cards in terms of read/write speeds. Their major advantage is the size and the fact that they are one of the cheapest forms of flash-based storage solutions. Generally capacities for MMCs range from 64 MB to 512 MB.
SmartMedia Flash Cards
Also known as SSFDC (Solid state floppy disk card) Smartmedia cards were introduced by toshiba in 1995. They became an instant hit at the time,thanks to their small size and super-thin architecture. With the arrival of MMC and SD cards,however smartmedia suffered a blow-today,only a few old devices use this type of storage. Their limited storage capacity and slow transfer speeds make the smartmedia format a less likely solution for the current breed of products. It is being rapidly replaced by MMC and SD storage.
xD Picture Card
xD (Picture) card slots are found in fuji and olympus cameras,as the cards were developed by these companies. xD cards are often sold under license and therefore you may sometimes find a different brand on the packaging,but a fuji or olympus branded card inside. xD cards have a distinctive,shield-style design and are roughly the size of your thumb. Storage capacity can be anything from 8 MB to 512 MB.
Similar to the sony memory stick,the xD picture cards are not used as a generic storage solution but are specific to products from olympus and fuji. Both these companies use the cards predominantly for digital cameras.
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