What is the right SD card for you - a simple English guide

Most cameras today use SD cards. SD or "Secure Digital" cards are permanent (nonvolatile) memory cards used in portable devices, like mobile phones, digital cameras, navigation devices, tablets, gaming consoles, etc. 

If you are a photographer or a videographer, chances are you need more than one SD card in your bag. But which ones are right for you? While shopping for a card might seems trivial, it's critical to purchase the proper card for the task at hand to avoid data loss or slow picture capturing.

There are 3 types of SD cards available in the market today. Two of them are mainly used in digital media today: SD and microSD. microSD is smaller and used in devices like smartphones, tablets, GoPro, etc. Both however are available in a variety of speeds, and come in capacities up to 128 GB. microSD cards might also include an SD adapter that allows you to use it in a standard SD card reader or device.

Standard SD cards are generally found in point-and-shoot and pro-level DSLRs, video cameras, and audio recorders. 


Knowing what type of files your camera / device is going to produce is critical in selecting the right size of the card. If you are shooting JPEGs you won't need as much capacity as if you are shooting 4K videos for example. RAW files coming out of a DSLR can be quite large compared to JPEGs. A full size RAW file once imported into your computer might take up to 32 Mbyte. For other uses such as audio recording, smartphone/tablet use, or a point-and-shoot camera (shooting jpeg), a smaller SD card will suffice.

Below is a summary guide of application versus capacity suggestions:

  • Audio: 4GB
  • JPG: 8GB
  • RAW: 16GB
  • SD Video: 32GB
  • HD Video: 64GB
  • 4K Video: 128GB

Speed Class Rating

Like capacity, speed is also important and is often overlooked by those unfamiliar with SD speed class ratings. Codes might seem complicated, but in reality it's simple to understand.

SD cards are available six different speed classes, from slowest to fastest:

  1. Class 2:  2MB/s - the slowest class available and are best suited for point-and-shoot cameras, audio recording, and low-resolution SD video recording
  2. Class 4: 4MB/s - these cards will work well with still cameras shooting jpeg files, and some very light HD video recording at 720p.
  3. Class 6: 6MB/s - work well with HD video recording (720p to 1080p/i) and smaller RAW stills 
  4. Class 10: 10MB/s - well suited for pro-level still cameras shooting full RAW photos, and HD video recording at up to 1080p. This is a great speed to purchase if you're looking for a balance between compatibility with your current equipment and future usage as well
  5. U1: 10MB/s
  6. U3: 30MB/s

U1 and U3 cards are compatible with the UHS transfer bus used in newer devices, so you will often see a card rated with both U1 and Class 10. That means that when the card is used on a standard high-speed data bus, it will perform at Class 10 speed, but when used on a UHS bus, it will perform at U1 speed.

U3 are overkill for most uses, but are a must if you're shooting 4K video. The cards are quite expensive at the time being.


Choosing the right SD card for your work is crucial. If you are a sports photographer you might consider a speed of not less than Class 10. This goes the same with your GoPro should you need to capture and later perform slow motions in 60 frames/s. A card too small could fill up quickly so have a bunch in your bag. I usually get the 8 to 16 GB in capacity for my still photography. I don't like big capacities because should something gone wrong with a card I don't want to loose all my photos thus I split my eggs in 2 to 3 baskets :) Also a card too slow could cause your device to choke and potentially causes data loss. 

Now you can go and have an informed shopping experience for those SD cards. Happy shooting!