Which Memory Card?
March 25, 2019
Whoever said that one of the keys to happiness was a bad memory probably wasn’t a photographer. Memory cards are the kinds of thing that beginning photographers start using and don’t think much more about until the day they either run out or fail. The more you shoot, the sooner you learn just how valuable it is to have at least one empty and reliable memory card—at all times.
If your camera was a head, and the lens a single staring eye, then the memory card would be like the camera’s memory – and just like people’s memories, some memory cards are more reliable than others. At CameraPro we carry mostly SanDisk memory cards as they have a proven track record of quality and reliability backed by a generous manufacturer’s warranty.
Which brings us to the question we get asked most frequently...
What kind of memory card do I need?
The answer to this depends on:
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What type of camera you’re using
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How much data (photos/videos) you plan to record, and
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How quickly you wish to record (and upload) that data
These factors will determine the type, capacity, and speed of memory card that you need.
Card Type
Memory cards come in a wide variety but most modern digital cameras will use one of six main types:
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SD (Secure Digital)
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microSD
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CF (CompactFlash)
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CFast (CompactFast)
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XQD
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CFexpress
(With the exception of XQD and CFexpress, the different card types are non-interchangeable.)
The type of memory card you need will generally be based on the camera you own. Some higher-end cameras will accept two different types of memory card but, in general, SD cards are the most common card type.
Capacity
Memory cards also come in different storage capacities, with our most common cards ranging from 32GB to 128GB, but with higher and lower capacity cards also available.
What size memory card do I need?
The answer to this depends on:
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The type of files you’re dealing with (i.e. JPEG/RAW format, resolution, bitrate) and
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The number of images or amount of footage you want to shoot before needing to clear the card.
For JPEGs and/or a few social or holiday snaps, you can get away with a smaller card (8-16GB). For RAW photo files, videos, and extended shoots you’ll generally need much more.
For a single shoot, we suggest as a bare minimum:
| Content Type | Minimum Card Capacity* | Card Type (if SD) | Speed Class | Speed Rating |
|---|---|---|---|---|
| JPEG photos only | 8-32GB | SD |
Minimum: C4 Recommended: C10 / U1 (UHS-I or II) |
Minimum: 40 MB/s Recommended: 80 MB/s+ |
| RAW photos | 16-32GB | SDHC | C10 / U1 (UHS-I or II) or U3 / V30 | 90 MB/s+ |
| JPEG/RAW photos + HD Video | 32GB | SDHC / SDXC | C10 / U1 (UHS-I or II) or U3 / V30 | 90 MB/s+ |
| 4K/UHD Video | 64GB | SDXC | U3 / V30 | n/a (refer to Speed Class) |
*You might require more (or even less) depending on how frequently you’ll be shooting, and for how long. More is advisable if you’re travelling, especially somewhere remote.
What’s the difference between SD, SDHC and SDXC cards?
The only difference between card types is capacity. SDHC is short for ‘SD High Capacity’; these cards can hold 4-32GB worth of data. SDXC stands for ‘SD Extended Capacity’; SDXC cards have capacities exceeding 32GB and can only be used with SDXC-compatible devices.
Should I get one memory card or multiple?
While it might seem obvious that you should just buy the biggest card and fire away with abandon, safe in the knowledge that you’ve got plenty of space, there are a couple of conflicting points of view on this.
Some people prefer to shoot on a bunch of smaller cards to minimise the risk of having a card fail and losing a whole shoot, while others opt for a larger card or two, preferring the risk of card failure over their own ability to lose a card or miss a shot while changing cards.
The advantages and disadvantages of each option are:
Multiple small cards
Advantages
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A corrupt card will only affect a small part of your shoot.
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Help you consider each shot if you know that space is limited.
Disadvantages
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More cards mean it’s easier to lose one.
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Missing a moment due to a full card.
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Having to swap cards in a damp or dusty environment could be dangerous to your cards and your camera.
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More wear and tear on the components of both your card and camera.
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More cards to keep track of when transferring your images to your computer.
Fewer cards with larger capacities
Advantages
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Less risk of losing a card as you need fewer and will keep a card in your camera longer.
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Less chance of missing an important shot while you change cards.
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Fewer cards to keep track of when transferring files to computer.
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Reduced chance of damage to the camera or card due to frequent changing.
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Larger cards are usually cheaper (on a per GB basis).
Disadvantages
In the case of a card failure you risk losing more, or all, of a shoot. This is the proverbial ‘all your eggs in one basket’ but can be alleviated somewhat if your camera has the option to shoot to two cards at a time; that way you always have a back-up.
Speed
Speed is the other key variable when it comes to memory cards. It’s important to understand the distinction between write speed (the speed at which your camera can write files to the card) and read speed (the speed at which your computer can read the files from the card), as well as speed rating and speed class.
Write Speed
Write speed is what matters in the field. This is especially the case for photographing in high-speed bursts, as well as 4K and 3D video recording. The faster your card’s write speed, the quicker your camera can clear its internal storage buffer—meaning the sooner you can take new photos and not miss a shot while waiting for your camera’s buffer to clear. A steady write speed is required to record video at an even rate, with no dropped frames.
Read Speed
Read speed affects how long it will take to empty a card onto your computer and in most situations is not a noticeable concern. You can plug your card into your computer, hit transfer and go make a coffee at your leisure; when you come back 20 minutes later your card will have finished dumping. However, if you shoot a LOT of pictures (e.g. for wedding photography) that transfer time quickly adds up. Faster cards will get your photos backed up and you onto bigger and better things in much less time.
What’s the difference between SD, UHS-I and UHS-II cards?
UHS stands for ‘Ultra High Speed’. Standard (non-UHS) SD card can only reach read speeds of up to 25 MB/s. UHS-I cards are capable of 104 MB/s and UHS-II cards can reach 312 MB/s—but only in compatible devices. The same rules apply to microSD cards.
Speed Rating (Rated Speed)
The speed rating, or rated speed, is the maximum transfer speed (in megabytes per second, MB/s) for writing and reading images to and from a memory card. (Some memory cards have different read and write speeds, in which case the speed rating indicates the card’s maximum read speed.) This is this speed you should expect to get with typical use, and is relevant to still photography.
Speed Class
On any SD card or microSD card you’ll generally see its storage capacity (in GB), speed rating (in MB/s), and a variety of other symbols and numbers. These symbols and numbers represent the card’s speed class, which indicates the card’s minimum sustainable write speed.
Speed class is important for video, which involves recording a steady data stream. Whatever format and resolution you choose will determine the minimum speed you require to record sustained, even footage with no dropped frames.
SD Speed Class
A number 4, 6, or 10 inside the letter C refers to an SD card’s ‘Class’, i.e. the minimum write speed in MB/s (megabytes per second) that it’s rated as capable of sustaining. So Class 10 cards are rated to write no slower than 10 MB/s (same as U1, below).
UHS Speed Class
Expressed as a number 1 or 3 inside the letter U, this rating is found on UHS-I and UHS-II cards. U1 cards are rated to write no slower than 10 MB/s (same as Class 10, above); U3 cards are rated to write no slower than 30 MB/s (but could have minimum write speeds higher than 30 MB/s).
Video Speed Class
Cards capable of 8K, 4K, 3D, HFR, HDR, and 360° video are identified by a video speed class rating (V_). V6 cards have a minimum rated write speed of 6 MB/s, V30 cards have a minimum rated write speed of 30 MB/s, V60 cards have a minimum rated write speed of 60 MB/s, and so on.
So what speed of memory card should I get?
This depends on:
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the type of files you’re dealing with (i.e. JPEG/RAW format, resolution and bitrate), and/or
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how quickly you want/need to photograph multiple shots.
Some cameras/devices require certain card types (e.g. CFast, XQD) largely because those card types satisfy their speed requirements.
For most other cases, here’s a rough guide to the minimum recommendations:
| Content Type | Minimum Card Capacity* | Card Type (if SD) | Speed Class | Speed Rating |
|---|---|---|---|---|
| JPEG photos onl | 8G | S |
Minimum: C4 Recommended: C10 / U1 (UHS-I or II) |
Minimum: 40 MB/s Recommended: 80 MB/s+ |
| RAW photos | 16GB | SDHC | C10 / U1 (UHS-I or II) or U3 / V30 | 90 MB/s+ |
| JPEG/RAW photos + HD Video | 32GB | SDHC / SDXC | C10 / U1 (UHS-I or II) or U3 / V30 | 90 MB/s+ |
| 4K/UHD Video | 64GB | SDXC | U3 / V30 | n/a |
Memory Card Care & Maintenance Tips
Whichever option you choose, you should always format your memory cards before use and regularly between shoots (after backing up your data, of course). This essentially ‘spring cleans’ the card of redundant or error-prone file info to help maintain the card's performance and storage capacity and prevent file corruption/loss, which can be timely, expensive, or impossible to fix.
Trusted brands like SanDisk are more reliable and less susceptible to errors. But no digital device or memory card is immune from malfunction. As the photographers’ saying goes, “If it doesn’t exist in three places, it doesn’t exist!” Be sure to make multiple copies of your files (e.g. on a physical hard drive and in cloud storage) and avoid storing files on your memory cards for long periods of time. It’s also a good idea to invest in a memory card wallet or holder to keep your cards protected and organised.
Find Out More
If you have any questions about memory cards, card readers or other products, we’d be more than happy to answer them. The staff at CameraPro are always available to offer advice on the card that would suit you best based on your shooting requirements. Feel free to visit us in store or contact us online or over the phone.