The question is often asked, “what size memory card should I buy?” The answer varies greatly and depends a lot on the megapixel count of your digital camera and how many photos or videos you take at a given time.
The actual number of images or length of video you can capture on a memory card depends on other things, too, such as the image resolution and compression settings you select in your camera, or if you shoot RAW.
Several other factors determine the actual size of an image such as amount of detail and number and shades of colors it contains. For example, the file size of a black and white image will be smaller than the same scene taken in full color. RAW files are much larger than JPEGs so keep that in mind when buying memory cards. For example, a test photo shot with a 10 MP camera, the RAW file was approximately 11.5 MB while the JPEG was 1.6 MB!
If you use Secure Digital memory cards, be sure to read about Secured Digital High Capacity cards and Extended capacity memory cards and their special features and requirements. There are also high capacity Compact Flash cards.
|Memory Card Capacity*|
|Camera||File size*||4GB||8GB||16GB||32 GB|
|5 MP||1.5 MB||2,400||5,000||10,000||20,300|
|6 MP||1.7 MB||2,000||4,300||8,700||17,300|
|10 MP||2.9 MB||1,200||2,500||5.000||10,100|
|16 MP||4.6 MB||700||1,600||3,200||6,400|
|21 MP||6.4 MB||550||1,100||2,300||4,600|
|VIDEO||HD1880p (5 Mbps)||–||–||02:00||04:00|
|*average file size for a high resolution JPEG Source: Lexar Media|
How many memory cards?
Many digital photographers have at least two memory cards, not only for the extra capacity but for security. If one card is lost, or if it becomes corrupted, you have an additional one on hand.
For those who shoot a lot of video with a digital camera, get the largest capacity card you can afford. Some photographers set aside one card just for shooting video.
Most digital cameras made during the last few years can take high speed cards and they are worth the extra cost.
Memory cards are relatively inexpensive compared to just a few years ago so get the highest capacity you can afford. It’s better to have extra capacity than to run out of capacity.