How To Choose the Right Memory Card for Your Camera

It’s important to choose memory cards based not only on your camera’s user manual, but also based on what kind of photography you plan to shoot and what you plan to do with the footage after the fact. Remember, the SD stands for Secure Digital – and you want to be sure you choose wisely to keep your investment secure, whether it’s for a hobby, collecting memories, or for professional use. 

how to choose the right memory card for your camera

Most photographers will tell you right up front, do not choose an SD card from a no-name company and expect excellent results. You may save a little bit of money in the beginning but in the end, you are taking a chance on being very disappointed in your pictures, if not losing them altogether. Some recommended brands include Sony, Samsung, Lexar, Transcend, SanDisk, PNY and Kingston Technology. 

Is there any proof that one brand is better than another? Not really. And I’m an amateur, so you don’t necessarily have to trust me. But these brands mentioned are the ones a lot of professionals use. And for them to lose pictures because of a card failure, means they lose money and possibly future clients. So, I wanted to present their recommendations for this article. 

The Differences in the Types of Memory Cards 

Standard SD Cards & Micro SD Cards

These cards are pretty much the same. The difference is just in the size. SD is used in most consumer/professional cameras out there. The MicroSD fits in drone cameras, action cameras with smaller spaces, etc… A MicroSD card generally comes with an adapter that it slips into (like a sheath) that makes it the same size as a regular SD Card. This gives you the option to insert it into whatever device you’re using for reading it, just like a normal SD size card. Some readers and computers actually do have MicroSD slots available. 

Compact Flash Cards

These are faster and are often used in more expensive and professional cameras. You’ll need to see if your camera has a port for this type of memory card. 

CFast Cards and XQD Cards

These are the fastest cards you can get. These are only used in Professional Level DSLRs and Cinematic cameras. Because it is so specialized, you’ll need to see if your camera has a port for this type of memory card. 

And now that we have that out of the way, we get to the difficult part (at least for me). Why is it difficult? Well, there’s math involved. Not my favorite subject. 

Understanding the basics about a memory card

This diagram shows you what each number is called and below we will go over that. There are multiple other types of memory cards out there, and your device will usually tell you which you need to use. But, all of them have the numbers in common. 

Memory cards last a very long time. It’s more likely that a memory card will become obsolete before it actually fails. Or, if it does fail, it’s usually because of damage done to it. If you do have a memory card failure that is not due to physical damage, the failure is likely to happen immediately. Therefore, it is probably a good idea to take some throwaway pictures and format your card a few times to make sure it works properly.

Keep in mind that on the side of these SD cards is usually a lock that works to keep you or someone else from accidentally formatting over what is on a card, thereby erasing something important. My suggestion is to use this so long as you don’t want things removed from a card. Once you are done with a project and have the data off of my card, I immediately flip this and reformat, so I don’t have to wait on this step before moving into the next project.

Another suggestion I have? Considering I have a graveyard of empty SD card holders and MicroSD card adapters in my desk drawer, I suggest having a case for your cards, so you don’t lose them. If you have one card you use most of the time, always keep it in the camera! You’re less likely to lose it or damage it if it’s in the camera.  When you’re downloading – DO NOT MULTITASK – for the love of all that’s holy, just do this until you have the images on your computer and can shove that puppy back in your camera to reformat it. That way you don’t forget where you put it.

To move on, we have to break out the math and the graphs and the charts – none of which I like. If you want to do this correctly, you need to at least try to understand the numbers on the memory cards and know you’ve got the proper card for your needs. However, you can always just ask a professional for help or find quick guides here and there, should you want to skip the numbers section. Up to you. 

How to choose the memory card you need


Speed is important for wildlife and sports photographers and videographers. Otherwise, if you go by your camera’s manufacturer guidelines concerning memory card recommendations, you should be fine. 

The number on the SD card that ends with MB/s is considered the speed of the card. This is the maximum reading speed of the card, in other words, how fast the card can be read by the device you plan to use for downloading your images.  Though this is important, it is not the only number you need to be concerned with when choosing a card for a project. 

Choosing speed is a process. You can look at how fast your data processes for a given method of filming to decide what base speed you need on your card. Notice that the camera measures in Megabit (little b) per second and the cards all measure in Megabyte (big B) per second. So you’ll need to do a few calculations to see what speed you want for the cards depending on which format I use.  

1 Mb/s = 0.125 MB/s 

8 Mb/s = 1 MB/s       

90 Mb/s = 11.25 MB/s

My older model DSLR can film either MOV+ALL-I  or MP4+IPB formats

MOV+ALL-I  (shoots at 90,000kbits/s) MP4+IPB (shoots at 30,000kbits/s) 

1000kB/s = 1Mb/s

 90,000kb/s = 90Mb/s and 30,000kb/s = 30Mb/s

So it shoots at a maximum of 90Mb/s or 11.25MB/s

My Canon M50 Mirrorless shoots at a maximum of 120 Mb/s and 120Mb/s = 15 MB/s

Considering most SD cards come with at least a reading speed of 30MB/s, this is essentially not that big of a deal. I just go for the higher reading speeds (at least 150 MB/s) and then focus on what kind of writing speed and space I need. And that is covered below. 


The writing speed is shown using the “class” numbers on the SD Card. This refers to the speed in which your image data is written onto the SD card in the first place. I’ll provide for you the classic table for deciding on which class is best for your work as well as the newer table version: 

The Class Speed really is just reiterating the MB/s speed you already see on the card, and isn’t overly important here. However, the other pieces of the chart are very important. Especially in video, where you care about minimum sustained writing speed.  If the sustained speed drops below the video’s bitrate, you get dropped frames. Dropped frames can leave a video very jerky and difficult to view. To know the card’s sustained speed, you are looking not just at the Speed Class, but the UHS Speed Class. 

U1 = never slower than 10 MB/s

U3 = never slower than 30 MB/s

Keep in mind non-UHS cards (cards under speed class 10) max out at 25 MB/s. That’s it. No matter what it says elsewhere, you will never get the better speeds. Most photographers do not use non-UHS cards and obviously, you should never use non-UHS for videography and expect anything. 

The V-speed lets you know what type of video a UHS card is capable of shooting: standard, HD, 4K, 8K, 3-D…etc… Not all cameras are capable of these speed classes, so don’t buy a card that is beyond your camera’s capabilities. You can find out what your camera’s limitations and recommendations are by reading the manual or looking it up online. 

Size/Space – Memory Capacity 

The size of the card is measured in GB. This is the memory capacity of the card. There is no reason to get anything less than a 16GB card. Generally speaking, no matter the cost, the amount you spend per gigabyte usually remains about the same within a brand. Obviously, the card will cost more for more memory space. Space is very important when it comes to the type of footage you’re dealing with.  

For example, shooting 4K video at a max bitrate of 120Mb/s 64GB will give you one hour. So if you need to film an event for 2 hours, perhaps go with a 128GB card space? Or if you want to  take a more cautious approach and use several cards on one project, go with 64 for one hour or 32 per thirty minutes. This is for those who worry that one card may get damaged – in this case you’d still have the other footage. But remember, that means changing out the card during the event. 

To give you a photography-only reference, you can shoot over 2000 RAW format photos and store it all on a 64GB card. A JPEG file is a format that is already converted to save space by compressing the data. So you can get more of these on a memory card than RAW files.  

Think about how much storage you actually need.  A 4GB SD card can hold about 280 RAW images and 1,500 high-quality JPEGs. A 128GB card would be a nightmare to manage, with almost 9,000 RAW images and 48,000 high-quality JPEGs. Many photographers prefer smaller-capacity cards that can be easily labeled and managed. Videographers go for somewhere in-between. 

To give you a video-only reference, I shoot video with my Canon M50 in up to 20 minute segments. With a 64GB memory card, I have no issues capturing well over 3 hours worth of standard video footage. I have no need for 4K, though it’s capable of handling about 120 minutes of it. 


Once you know what kind of card you need to purchase, this listing gives you the basics on the minimum requirements for the type of shooting you plan on handling. Again, these are minimums and every year technology goes further and further. 

The biggest suggestion I see out there is to get the fastest card that is compatible with your camera, so you don’t have to buy a bunch of new cards in case you upgrade. If you plan on a lot of filming, more space and speed is always advisable. I found that it has always been easier to use one card per project to keep my photography and videography organized. 

But at the same time, don’t go after the maximum space available if you don’t have to. Sure, if you film events and need a lot of space, that’s one thing. Most of us just film or shoot pictures, then download them to our computer and reformat the card afterward. For that, you don’t need to spend the extra money on the fastest card with the most space. 

Use your camera’s references, use these references, choose a quality card, and get what you need from your memory cards. 

JPEG Photography

Reading Speed30MB/s
Writing Speed – Class10
Storage Capacity16GB at least, but 32GB usually doesn’t cost much more and it allows you twice as much space. 

RAW Photography and FullHD Video

Reading Speed45MB/s
Writing Speed – ClassU1 – 10
Storage Capacity32GB same here, you could take 32 and be fine, but you can double the amount of space and keep yourself from having to grab another card by just purchasing the next higher tier.

4K Videography

Reading Speed60MB/s
Writing Speed – ClassU3 – 10
Storage Capacity64GB at least. These cards are going to be more expensive as you go upward. 


As I talked about in this article, it is really important to have the right equipment for the job and memory cards are no exception. If I can give you any advice you can take to heart, it would be that. I have written other articles on this site covering the basic cameras and other articles that I would encourage you to check out while you are here.

There is also a great article on memory cards that was published by B&H Photo that would be an additional resource for you to read.

Be sure to drop me a comment below to let me know which memory cards you typically use.

Rachel Adams

I have used a wide variety of cameras over the years and wanted to share my experiences and knowledge with my readers. I don't have a degree in photography and I don't do this professionally. So, if you were looking for a photography expert - sorry. But if you prefer a practical person who admits she’s been a noob to photography and has learned from good people and through trial and error? I’m here for ya!

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