Memory Cards
As mentioned in Chapter 2, you will almost certainly need to buy a memory card when you purchase a new camera. Each camera requires a specific type of memory card, and if you are shopping for a new camera, the type of memory card required might be one of your considerations.
There are many different cards. For example, the Secure Digital (SD) card can be used in a number of devices. If you already own a gizmo such as a PDA or GPS, you may be able to use the card you already own for that device in your camera.
There are a variety of memory cards. They go by names such as:
Compact Flash cards (CF)
MicroDrive (MD)
Memory Stick (MS / MS Duo)
Memory Stick Pro
Multi Media Cards (MMC)
Smart Media (SM)
xD Picture Card (xD)
Different types of cards may cost more than others and their capacities, and cameras' limitations on capacity, can vary.
Memory cards come in a range of sizes, everything from 8 megabytes to 8 gigabytes. As with many things in the computer world, you will often pay much less per megabyte the larger the card you buy. However, memory cards are not perfect and if you have a large card and the card fails, then all of your pictures will be lost. For this reason, many photographers prefer to have several smaller cards so that they don't put all their eggs in one basket.
Memory cards over 2 gigabytes may not be compatible with all devices that normally accept that type of card. The larger capacity cards can require a different kind of computer addressing, which may not be compatible with older gizmos. Check the device manufacturer's Web site before buying.
The picture storage capacity of a memory card can be confusing and hard to understand. Because JPEG images are compressed, the actual size of the stored picture file is often about half of the megapixel rating. For example, a 2-megapixel image will often only have a file size of about 1 megabyte and a 6-megapixel image only about 3 megabytes.
This means that:
A 128MB card will hold 130 2-megapixel photos or 40 6-megapixel images.
A 1-gigabyte card will hold about 1,000 2-megapixel photos or 300 6-megapixel images.
The above numbers refer to JPEG files and the corresponding megapixel rating of your camera. If you are saving TIFF files or RAW files, the capacity will be much smaller. Consult your manual for information about the approximate size of these files.
Never remove a memory card while a photograph is being saved. This can corrupt the picture file and even the entire card, making it unreadable. If this happens, recovery software may be able to retrieve some files and/or reformat the card. This type of software works with memory card readers.
You may be able to put a card into your camera and be up and running with no need to do anything further. Yet a memory card is very much like a hard drive or disk in that it needs to be formatted so that the camera can read it and write to it properly. Therefore, the first time you use a card it is not a bad idea to format that card just to be certain that the card is correctly configured for the camera. Read the camera manual for instructions on how to do this, as it will vary from camera to camera.
Formatting can be useful for other reasons. If you keep getting error messages when you save pictures to the memory card, reformatting may solve the problem. Bear in mind that formatting will erase all information on the card. For a quick delete of all pictures on your memory card, formatting is also useful. This can be much faster than deleting all the pictures or going through and deleting them one by one.
Memory cards normally work well, but there are things to be aware of:
Never touch the delicate prongs or metal contact areas.
Make sure the prongs and metal contact areas are clean and clear of any dust.
Avoid losing the cards.
Store them in a case that keeps them from getting dinged up or lost.
