Memory cards play a HUGE roll in photography. You HAVE to have them! The question is, do you value them? Do you know why you should value them? Let me show you why a memory card is so important and why you shouldn’t skimp when buying them.
The first and usually the biggest and most advertised number on a memory card is the capacity. This is how many pictures it can hold. However, the most IMPORTANT number is the smaller number. It usually says anywhere from 35mbps to 95mbps. That is the SPEED of the card. The faster the speed, the quicker it can read and write. If you have a slow card, your camera can not write to it fast enough and it gets bogged down. The faster the card, the more pictures you can take before your camera slows down.
If your memory card does not have the write speed written on it, it is most likely a slow card.
If you have ever been taking pictures quickly (sporting event, bride walking down the aisle, kids blowing bubbles, etc… ) and your camera just stops or slows down before it can take another picture, your memory card is most likely the culprit. Another great thing about fast memory cards is that they read faster so getting images off your card and onto your computer is faster.
Besides the speed of the card, the better memory cards are built better. I have washed and dried my memory cards and they are still fine. I have never had a good memory card corrupt or lose images. Think about it this way, why spend THOUSANDS on nice camera bodies and lenses and then trust the images (the whole reason you're a photographer) to a cheap memory card! Spend money, get a reliable memory card, you don't want to tell a bride you lost her wedding because you didn't want to spend a few extra dollars on a memory card.
When shooting video, a large amount of data is getting moved from your camera to the memory card so if your memory card can not handle the huge amount of video data, your camera won’t even let you take video.
If you want to get crazy and learn a little more, I have a free side note here. Besides your memory card which is the most important part of this system, your camera's buffer plays a roll in image recording too. he camera buffer is a middle man between your camera and the memory card. While your camera is waiting to write to the memory card, images are stored temporarily in the buffer. The bigger the buffer, the more images it can hold. You can not change your camera buffer but you can buy a nicer (more expensive) camera and they usually have a bigger buffer. The Nikon D5 can hold over 100 files in the buffer, so it pretty much never stops. My old D7100 only holds about 8 RAW images so that buffer would fill up really fast during fast action.
So. while yes, memory cards do matter, megapixels DON'T! Click here to check out my video and blog from two weeks ago on the megapixel myth!