Reading the photo blog of another photographer got me thinking, when shopping for memory cards for your digital camera the speed is usually more important than the capacity. In regards to storage most people people think more space to store stuff is better but on your camera it’s better to go for speed first.
Memory cards are cheap and it’s not hard to buy multiple decent sized cards for your camera. 8 to 16 GB will cover all but the highest resolution cameras for a few days. The true limiter with digital photography is the battery life, just like we used to carry multiple rolls of film in the analog days, today we carry multiple batteries. You’ll need 2-3 batteries a day, but a small 8GB card will last you 1 day or a weekend depending on how much you shoot and if you shoot RAW (you should shoot RAW)
But a separate issue from that is the time it takes to dump the image from your camera’s buffer to the memory card and this is where the card’s Speed class comes into play. Speed of a card will correspond to a huge increase in price but is worth the money when it’s destined for your camera. Skimp on size and focus on speed.
For example: Instead of a class 4 64GB card, spend the same money for a class 10 8GB card. If you really have an issue with running out of space buy another card as a backup (although in my experience even a 8GB card is fine if you empty the card regularly). Wikipedia has a section that details how SD Card speed classes work. Basically look for a circle with a 10 in it, or U with a number in it (1 and 3 are the current options).
However be wary of bogus SD Cards sold by fly by night shops (I also boycott PNY, but that’s a personal issue due to bad customer service in the past). For more on why it’s good to buy from a reputable seller check out this blog article.