How to Choose a Memory Card for Your Camera

July 11, 2025

How to Choose a Memory Card for Your Camera

A memory card is an essential part of a camera. Its specifications affect the camera’s performance, the quality of video recording, and even the safety of your data. Let’s break down how to choose a memory card that fully meets your needs.

1. Key parameters of a memory card

Memory card capacity

The capacity of a card is indicated by numbers with GB or TB labels. The larger the capacity, the more photos and videos it can store. However, there’s an important nuance:

If you use a large card (128 GB or more), you risk losing a massive amount of data if the card fails.
Using several smaller cards (16–32 GB) and swapping them during shooting minimizes the risk, as only part of the material would be lost in case of a failure.

For standard photography, 64 GB is usually enough. For high-resolution video, it’s better to use a card of 128 GB or larger. If your camera has two slots and supports recording duplication, using a single large card (128–256 GB) becomes safer and more convenient.

Write and read speeds

W (write) — Write speed: critical for continuous shooting and video recording.
R (read) — Read speed: affects how fast you can transfer files to your computer.

If only one speed is indicated (e.g., 80 MB/s), it’s usually the read speed. For photo and video work, write speed is more important.

Look for cards with write speeds of 100 MB/s or higher if you plan to shoot 4K video or do continuous RAW bursts.
For slower-paced RAW photography without bursts, a write speed of 30–60 MB/s is sufficient.

Video speed class (V6–V90)

This rating indicates the minimum sustained write speed for video:

V6 — HD video (6 MB/s)
V10 — Full HD
V30 — 4K video
V60 and V90 — for 8K video and high-bitrate recording.

If you shoot in 4K or 8K, choose cards rated V60 or higher to avoid recording interruptions.

How to Choose a Memory Card for Your Camera: Complete Photographer’s Guide

2. Types of memory cards

SD (Secure Digital Memory Card)

This is the most popular card format, supported by almost all modern cameras, including Canon, Nikon, and Sony. Current SD card types include:

SDHC — up to 32 GB

SDXC — up to 2 TB

SDUC — up to 128 TB

Eye-Fi — cards with built-in Wi-Fi for wireless file transfer.

Choose the latest generation cards (SDXC), but make sure your camera supports this format before purchasing.
CF Cards

CompactFlash (CF) cards were traditionally used in professional cameras due to their high speed and reliability. They are ideal for recording large amounts of data and working in harsh conditions.
However, note that the CF format is gradually becoming outdated. Modern mid-range and high-end cameras are increasingly switching to faster standards like CFexpress and SD UHS-II. If you plan to upgrade your gear in the coming years, it’s better to focus on these newer formats.

MicroSD Cards

Originally designed for smartphones and drones, MicroSD cards can also be used in cameras with an adapter.
Some sources claim that MicroSD cards are less reliable. However, modern MicroSD cards from leading brands (SanDisk, Samsung, Lexar) combined with a quality adapter are almost as reliable as SD cards. Their main advantage is the affordable price.

3. Additional features

UHS Bus Version (I, II, III)

This is indicated by Roman numerals:
UHS-I — basic speed
UHS-II and III — offer higher performance thanks to a second row of contacts.

If your camera doesn’t support UHS-II or III, there’s no point in paying extra for such cards—they will still operate at UHS-I speeds.
Speed Class (C2, C4, C6, C10)

This rating shows the minimum guaranteed write speed (in MB/s):

C2 — 2 MB/s

C10 — 10 MB/s

The higher the class, the better the card handles photo and video recording.

Conclusion

If you shoot in RAW and record 4K/8K video, choose SDXC cards with a V60/V90 rating, write speeds of at least 100 MB/s, and UHS-II bus version.

For standard photography, cards with a C10 rating, write speeds of 30–60 MB/s, and 64 GB capacity will be sufficient.

Don’t be afraid to use MicroSD cards as long as they are from reputable brands and paired with high-quality adapters.

Tips for Protecting Data on Your Memory Card

Format the card only in the cameraAlways format your memory card in the camera, not on a computer. This creates a file structure optimized for your camera model and reduces the risk of writing errors.
Never remove the card during recordingDo not take out the memory card while the recording indicator is flashing. This can corrupt files and damage the card itself. Wait until the recording process is complete before removing it.
Use cards from reliable manufacturersBuy memory cards only from trusted brands and official suppliers. Cheap cards are often counterfeit.
Back up your data regularlyAfter each shoot, immediately transfer photos and videos to your computer and make backup copies on an external drive or in the cloud. Don’t keep important files only on the memory card.
Avoid filling the card to capacityTry to keep at least 10–15% of the card’s space free. Completely full cards are more prone to file system errors.
Replace cards over timeEven high-quality memory cards have a limited number of write cycles. Professionals are advised to replace cards every 1–2 years of active use.