Which SD Card for your Camera?

Choosing Memory Cards for your Digital Camera

Camera Memory used to be exclusively the Compact Flash Card but technological advances first saw cards shrinking to the size of the SD card (Secure Digital) and then advances in mobile phones brought us the Micro SD card. (Post updated May 2016) One would used to think smaller meant less capacity but in the case of SD Cards the opposite has happened with the latest now boasting a staggering 512 gigabits of memory plus it’s waterproof, dustproof, X-ray proof and lots more – Sandisk Extreme Pro 512 gb .  With the relatively rapid advances in capacities and transfer speeds has come confusion as there are now an array of cards available.  So which memory card do you need for you camera?  No point in spending too much and little point in buying something that is not “fit for purpose”.

What SD card should I buy for my camera?

We have over the last two years seen a trend away from compact flash cards to SD cards and Nikon appear to be leading the way ahead of Canon for this migration with all of their recent models now accepting SD cards … the high end Nikon D800 accepting both SD and Flash. In the case of Canon the following models accept all of SD, SDHC and SDXC cards – Canon Rebel SL1 (100D), Rebel T3i (600D, Rebel t4i (650D), Rebel T5i (700D) , Rebel T6i (750D), Rebel T6s (760D),  Canon 6D, Canon 7D Mark II, Canon EOS M.  In the higher end models the 5D Mark III takes all of these SD cards plus Compact Flash and the Canon 1DX accepts Compact Flash Only.  See below for a Canon Chart Additionally, some recent models accept Eye Fi Cards , SD cards that enable the wireless transfer of images. Sony’s range of SLT cameras in common with Nikon and Canon accept SD, SDHC, SDXC but additionally their own Duo Memory Sticks. Nikon Memory Card Checker

What is the difference between the various SD cards?

Acquiring memory for digital devices including cameras, video cameras, tablets and phones has become a little bit complicated because manufacturers use different types of flash memory to create an SD memory card.  For this reason transfer speeds can vary and the codes on cards confusing. The key elements of an SD card are the memory and the speed of transfer between devise and card.  Capacity needs little explanation and with the increased sensor capabilities of cameras, photographs and long video clips can devour memory.  Transfer speed is crucial for video recording but also important with compact and DSLR cameras when shooting a multiple photographs.  If the card cannot cope with what is being captured, the video will become jerky or worse the recording will freeze.  Something I have experienced… firstly, I thought the camera was broken then realized I had an old Class 2 SD card with low transfer speed. Recording video requires a constant minimum write speed to ensure a smooth playback. In the case of still photographs, particularly if your are simultaneously recording in RAW and JPEG, the frame rate will be limited with a low rated card.  I  experienced this too when photographing a golfer’s swing. My Canon 7D Mark II will shoot at 10 frames per second but this drops off if the card cannot work with the camera at a fast enough transfer rate. SD cards for Cameras Speed Class has been standardised and is indicated by speed symbols to help consumers decide which SD card will provide the required minimum performance for reliability. There are two kinds of speed indications Speed Class using the C symbol and the more recently UHS Speed Class using the U symbol.   The Speed Classes defined by the SD Association are Class 2, 4, 6 and 10 referring to the number of MB/sec.  UHS (Ultra High Speed).  UHS, the fastest performance category available today, defines bus-interface speeds up to 312 Megabytes per second for greater device performance. It is available on SDXC and SDHC memory cards and devices. The Class rating system is limited but it can be a useful guide to the capabilities of different cards. A class 2 rating is fast enough for Standard Definition video recording, whilst classes 4 and 6 are fast enough for Full HD video (which one you need will depend on the bit rate of the video format you’re using). The highest rating, class 10, is faster than required for even HD video standard as the frames are comparatively low resolution of around 2 megapixels. The higher Class Cards 10 and UHS are aimed at photographers since they minimise the time it takes to write a photograph to the card.  Photographs on a consumer DSLR may be around 12 megapixels whereas high-end models often record more than 20 megapixels. Each image can therefore contain ten times as much information as a frame of video. Photographers wishing to capture the full tonal depth and quality of a scene will probably shoot in Raw mode, with no compression applied as would be the case with a JPEG image.   On my Canon 7D a single photograph captured in this way can easily require 25-30 MB of storage.

The SD Card’s smaller relation

MicroSDA few words about the Micro SD card as used in tablets and smartphones  In most cases, unlike as with a camera, you don’t need to go for a very fast SD card. A Class 4 or 6 card that’s capable of recording HD video will also be fast enough to play it back. However a faster card will sync with your PC much quicker, so if you regularly transfer big movie files or folders a card with a high transfer rate is worth considering.  A fast Micro SD card will also make games and utilities load more quickly, but often the difference won’t be noticeable.


A summary of which SD card is best for you?

  • Older Compact Camera Photos and Standard Video only – Class 2 SD will suffice.
  • Modern Compact Camera for Photos and HD Video – minimum of Class 4 or 6 SDHC.
  • Tablets and Smartphones – minimum of Class 4 or 6 MicroSD but consider faster if transferring large files between tablet and PC.
  • Modern Digital SLR Camera for Photos and HD Video – minimum Class 10 or UHS 1 SDHC/SDXC rated at 45MB/sec

The cost of memory has reduced dramatically in recent times.  There are many trusted names out there but this SanDisk 64GB 45MB/s with both large capacity and fast transfer speed is close to the ultimate for most. Enough Space for roughly 25,000 photos and what a bargain – originally a lesser version of this 64 gb card was at $199 but but you can now buy twice the capacity in the shape of the Samsung 128gb for just $47…..check out these cracking deals