Selecting the correct memory card
Mike Worswick, CEO of Wolfe's Camera
This is a quick guide to the complexities and confusion in choosing memory cards. Among questions we will answer include; "Is it OK to use a $5 memory card or do I really need a higher priced card?"
The first step of selection is the physical card shape and style. By mid 2011 the most common memory card for cameras is almost exclusively in the SD family. Some current cameras continue to use compact flash (CF) cards. Older Sony, Olympus, Fuji and a few other brands used different card types. So if you have 3 year or older camera you may need a memory stick, memory stick Duo, or XD card. There are a few very old Fuji and Olympus models that require a smart media card (SM). If you have one of these consider buying a new camera. Technology has moved so far that investing in a card for one of these will not be a good investment.
SD cards come in various forms. There is a card called a micro SD card. This is a tiny card that is often used in cell phones. It is terrible in school use because it is so easy to lose. The card must also be inserted in a special adapter before inserting into a computer. Only use these if it is the only option.
Regular SD cards are about the size of a postage stamp. They are divided into two types SD and SDHC (high capacity). Some older cameras (2005 and earlier) many only take SD cards. Both of these card types are the same physical size. SD cards are 2GB and less in capacity. As of today only the 2GB is readily available. SDHC cards start at 4GB and go up to 64GB.
What makes cards vary so much in price? The obvious answers are memory capacity and operating speed. Less obvious is the type of chip components and construction which is then packed inside the plastic shell.
Let's start by considering size. Will you be shooting only still photos? Most cameras shoot video which is a memory hog. In a school or business environment, smaller cards are usually better. It is faster to download files plus there are fewer photos to go missing if the card locks or simply is lost. For classroom use, I recommend that each student be provided their own memory card. This will prevent many issues related to shared files and content.
The number of megapixels of the camera is also a determining factor. Memory cards used to be very expensive per megapixel. Not so today. Some new cameras in 2011 will have sensors as powerful as 24 megapixels. They will require a card three times larger than an 8 megapixel camera to save the same number of photos. Just check our card sizing chart (see below) to see about how many photos or minutes of movies you need. Speed of the card is a determining factor in card cost.
Speed of the card means how long it takes for the card to write (accept) the data from the camera after the picture is taken. The second measure is read speed which is used when you look at photos or transfer them to a computer. For a basic $100 camera there is little speed concern. The camera operating system is probably slower than most cards. Card speed becomes critical with larger capacity cards, more complex cameras, and those shooting video.
There is no absolute standard among card makers as they rate cards. The SDHC association tried to standardize and you rely on their numbers. Some very inexpensive unknown brand name cards may exaggerate their speed. Beware. SDHC cards are graded as class 2, 4, 6 and 10. Now there are SDHC cards that far exceed the original class 10 definition. You will see terms like 45MBS or 60MBS. The new official definitions are U1 and U2 (where the number is cradled in the U on the memory card label). What is really important? In SDHC cards choose a class 6 or higher card. In simplified terms never buy a class 2 or class 4 card to shoot pictures. Oh yes, they would work for a snapshot but could cause problems when you shoot a video clip or a fast sequence of still photos. Newer still cameras can take from 5 to 14 or more full resolution photos in one second.
Our recommendation is never use less than a class 6 card for SDHC. If you are buying a new high speed Sony or other high end SLR choose class 10 or faster. For compact flash (CF) cameras the ProMaster 60x cards are perfect unless you have an advanced camera that shoots quality video. Then you want a faster card with 400 to 600X speed.
Internal card construction is also important. This is the hardest part for you to discern when card shopping. Memory card chips are fabricated on a base of silicon material. The largest makers of memory chips are Toshiba, Samsung and SanDisk. There are a number of smaller makers as well. These suppliers try to get more memory capacity onto a tiny chip that still fits into the little plastic housing called an SD or SDHC card. Originally there were single layer cards, then multiple layer (2 layers) and now triple layer cards. These triple layer cards are inexpensive to build. That is why you may see 4 and 8GB cards priced at or under $10. Beware of these cards. Many have write speed issues. Currently they are all class 4 or slower. More dangerous is that they have a much greater risk of card failures. It has been reported that TLC (triple layer) cards may fail after 5,000 read-write cycles. One cycle occurs every time you turn on the camera, take a picture or view a different photo on the card. For the small cost difference avoid these cards. Over time you will appreciate having a more reliable memory card. Even brands like SanDisk are using triple layer memory in their inexpensive cards. You can rely on ProMaster cards of all speeds or SanDisk's class 10, U1 and U2 cards.
There is one more quality improvement in memory card manufacture. ProMaster has worked with their factory who builds memory cards for extremely rugged use. The process was designed for the U.S. military which needs cards to work in adverse environments. AWXC cards made by ProMaster are built with the highest quality components. Then they are encapsulated in a material than makes them dust proof, waterproof and shock resistant. They are then placed in the plastic housing where they look and work like an ordinary SDHC or CF card. They are just far more reliable.
The general summary for card selection is choose class 10 or faster cards for SDHC cameras that are advanced in performance. Choose 300x or faster CF cards for SLR cameras with video capability. Consider ProMaster AWXC cards for maximum performance and reliability. All ProMaster cards include a lifetime warranty.