Sd Card For Video Cameras

Does SD Card Speed Really Matter?

The two little numbers with the circle and U shape around it is known as the speed classes of the memory card. Every single SD card has a class labeled on the front side. Manufacturers use these "classes" to determine the speed of the memory card. For example, you will need a faster memory card if you are shooting RAW or HD videos. In contrast, you do not need a very fast memory card if you plan on just storing a couple photos or documents. So before you buy that insane deal online for that 16GB SD card you saw, be sure to check which speed class it is. There are class 2,4,6, and 10 memory cards. Class 2 being the slowest and 10 being the industry standard. Hardly anyone uses class 2-6 memory cards nowadays and if you do, you have some catching up to do. There are also two Ultra High Speed (UHS) memory card classes that are more common now and many of the high-end cameras need at least a UHS-3 (U3) for many of the functions. To put it into perspective:

Class 2: standard video recording
Class 4: short HD video recording
Class 6: short HD video recording
Class 10: RAW photos, continuous HD video recording
Class 1 or 3 (UHS): Continuous HD video recording, large RAW files, 4K video

1. You need a fast card to shoot in certain modes on your camera.

For example, the Sony A7Sii requires you to have a UHS-1 or U3 card. It requires a memory card that can support the MB/s when shooting video. This can happen:

Sony a7sii sd card

If you are trying to shoot a 4K video (XAVC S 4K - 3840 x 2160) at 24 frames per second, you will need a memory card that can support the required 100mbps. You can shoot in these frame rates at 60M as well, but we recommend shooting in the highest Mbps for better quality and less risk of dropped frames.

When trying to shoot in HD (XAVC S HD - 1920 x 1080) at 120 frames per second, you will need a memory card that can support the required 100mbps.

2. A faster card will improve download and read time.

In other words, when you plug in your SD card to import the files onto your desktop, it will import a lot faster since it has a higher bit rate. With a slow smaller card, you will be falling asleep by the time the import gets finished. Okay, that may be an exaggeration, but you get the idea. Additionally, with a faster card, your camera will have less buffer (or "lag") time. So when you are shooting photos at rapid fire or trying to quickly stop a clip to start the next, a faster SD card will help you out.