Secure Digital memory comes in several types.
The popularity of digital photography has exploded in recent years. Many people focus only on which digital camera to buy. Of equal importance is which memory card you should buy. Depending on what camera you purchase, you may need to decide between two types of secure digital media. Two of the most popular are SanDisk Ultra and SanDisk Extreme. Each product has its own benefits.
Types
Secure digital memory cards from SanDisk are split into two distinct product families: the two product lines ultra and extreme. The Ultra product moniker is used to market the Secure Digital Extended Capacity (SDXC) product. The Extreme product line features memory cards that are compliant with the Secure Digital High Capacity (SDHC) standard. The two SD memory product types are built in accordance with two disparate standards.
Function
Both SDHC and SDXC memory cards are solid state memory cards. This means that unlike a hard drive, neither of the devices has moving parts. All SD memory cards are designed to be removed from the device in which it is used. Each card features a "clipped corner" shape to help the consumer correctly insert the memory into the device. Though used mostly in cameras, SD cards are also used in other devices, such as portable music players and cell phones.
SDXC Advantages and Disadvantages
Ultra (SDXC) memory cards are designed for high-megapixel digital cameras and high-definition camcorders. Ultra SD Card features include sizes up to a potential 2 terabyte capacity and transfer speeds of up to 15MB/s. These features make this type of memory card suited for higher-end consumers who need to store large amounts of photos. This format is also well suited for those using equipment capable of shooting high-definition video footage. Conversely, the transfer speed is much slower than it's SDHC sibling---photos will take longer to download to your computer. This slower speed will also make it harder to capture long series of quick, multiple exposures on your camera.
SDHC Advantages and Disadvantages
Extreme (SDHC) products are also designed for high-megapixel digital cameras and high-definition camcorders. The main advantage of the Extreme line over the Ultra line is the file transfer speed. SDHC is twice as fast---up to 30 MB/s---as SDXC. As of 2010, the specification for SDHC limits these cards to 32 gigabytes in size. This difference in size will be significant to videographers, as HD video produces extremely large files. This means that an Extreme card can store less raw video than an Ultra card. An Extreme 32GB SD card can hold about eight hours of high quality video, versus 240 hours on a 2 terabyte Ultra SD card.
Considerations
The final and most important part of your decision should be what's of greatest importance to you. If you intend to store hours worth of video, your best choice might be the higher storage capacity of a SanDisk Ultra SD card. If you are looking to take many multiple quick exposures, you might need the fast transfer speed of a SanDisk Extreme card. For the typical family photographer, price will also be a consideration. Ultra SD cards tend to provide more storage for the same price. Ultra SD cards can often be found offering twice as much storage at the same price as an Extreme SD card.
Tags: memory cards, Extreme card, transfer speed, Advantages Disadvantages, cameras high-definition
