A Quick Guide to buying a suitable memory card for your camera.
The majority of entry-level and intermediate range SLR cameras use an SD (Secure Digital) type card. Professional SLRs usually use the CF (Compact Flash) format. To look at they are easily distinguishable because the SDs are smaller, rectangular and have one of the corners cut at an angle, while the CF are larger and almost square.
Inside, the SD cards have evolved with regards to capacity and speed of recording. Regarding capacity:
- SD: It is the oldest, original format with capacity up to 2 GB. These days they are rarely used.
- SDHC: Capacity up to 32GB
- SDXC. Capacity over 32GB (up to 2TB)
While the capacity is important, the speed of recording is even more important. SD cards are organised into classes, each class ensures a certain minimum recording speed (sequential write speed, more on this later).
There are currently three different classifying systems: Speed Class (C2 to C10), UH Speed Class (U1 and U3) and the new classes aimed at video Video Speed Class (V6 to V90). They are independent of each other, but for practical purposes, what matters is to know what can work for our camera and what is the most appropriate.