While most cameras have internal memory, most don't have enough to make it worthwhile — so most photographers rely on memory cards to store their photos. There are at least six types of memory cards that consumers have used in digital cameras in the past. Most new cameras use SD memory cards, but CF (CompactFlash) memory cards are still used today, especially in high-end cameras. They are typically slightly larger than a postage stamp and can store thousands of photos.
How do I resolve the 'CF card cannot be read' error?
As with all media, CF cards can develop problems. Given the nature of photography, this can be disastrous, especially for professional photographers. Regularly backing up images to another source (your computer, an external hard drive, or the cloud) is crucial, but there are a few common issues that you can take steps to resolve:
Card recognition issues. Your camera may have trouble recognizing high-capacity CF memory cards (usually at least 16GB) or reading the entire memory space. If this happens, your camera may need a firmware update or upgrade. Check your camera manufacturer's website to see if one is available.
Slow, choppy performance. If your CF card's downloads seem slower and less smooth than you expect, the card may not support the UDMA (Ultra Direct Memory Access) protocol. Older CF cards use PIO (programmed input/output) protocols, which transfer data more slowly than UDMA. Because UDMA-enabled CF cards are more expensive than PIO CF cards, you may have a mix of both types of cards in use. The solution is to upgrade to a UDMA card.
