Why Your Memory Card Matters
Your memory card is the bottleneck between your camera's sensor and your images. A card that's too slow causes buffer delays (the camera freezes mid-burst), dropped video frames, and frustrating wait times when writing files. A card that's unreliable can corrupt an entire shoot's worth of images. Spending a few extra dollars on a quality card from a reputable brand is one of the best investments in your kit.
Card Types
SD / SDHC / SDXC: The most common format for consumer mirrorless cameras. SD cards top out at 2GB, SDHC at 32GB, and SDXC at 2TB. In practice, you'll buy SDXC cards in 64GB, 128GB, or 256GB sizes.
CFexpress Type B: Used in professional bodies like the Nikon Z8/Z9, Canon R5 II, and Sony A1 II. Dramatically faster than SD — necessary for 8K video and high-speed bursts. More expensive.
CFexpress Type A: Sony-exclusive format used in the a7 IV, a7R V, and a1 II (which takes both Type A and SD). Compact but costly.
microSD: Used in action cameras (GoPro, DJI) and drones. Same speed classes as full-size SD.
Speed Ratings Decoded
| Rating | Min Write Speed | What It Means |
|---|---|---|
| UHS-I | Up to 104 MB/s bus | Sufficient for most entry-level cameras, 4K30 video, moderate burst shooting |
| UHS-II | Up to 312 MB/s bus | Required for high-speed bursts, 4K60+ video, and cameras with UHS-II slots |
| V30 | 30 MB/s sustained | Minimum for 4K video recording |
| V60 | 60 MB/s sustained | Recommended for 4K60 and high-bitrate video |
| V90 | 90 MB/s sustained | Required for 8K video and professional workflows |
Trusted Brands
SanDisk Extreme / Extreme Pro: The industry standard. Extreme (UHS-I V30) for general use; Extreme Pro (UHS-I V30 or UHS-II V60) for higher performance. Widely available and well-tested.
Samsung EVO Select / PRO Plus: Excellent reliability and performance. The PRO Plus line offers UHS-I V30 speeds at competitive prices.
Lexar Professional: Strong performer in both SD and CFexpress formats. The 1667x (UHS-II V60) line is a favorite among professional photographers.
Sony Tough: Premium cards with IP68 waterproofing and bend-resistant construction. Overkill for casual use, but trusted by professionals in extreme conditions.
How Much Storage Do You Need?
A 24MP camera shooting RAW produces files around 25-30MB each. A 64GB card holds approximately 2,000 RAW images. For a day trip or casual session, 64GB is plenty. For a multi-day trip, wedding, or event, 128GB or 256GB provides comfortable headroom. Two smaller cards (2× 64GB) are safer than one large card (1× 128GB) because a single card failure loses half the images rather than all of them.
Recommended Cards
Best value: SanDisk Extreme 128GB UHS-I V30 — Shop Amazon | Shop eBay
Best performance (SD): SanDisk Extreme Pro 128GB UHS-II V60 — Shop Amazon | Shop eBay
Best budget: Samsung EVO Select 64GB UHS-I V30 — Shop Amazon | Shop eBay
Frequently Asked Questions
What speed SD card do I need?
For most mirrorless cameras, a UHS-I V30 card is sufficient. If you shoot 4K60 video or rapid bursts, upgrade to UHS-II V60.
Does the brand of SD card matter?
Yes. Stick with SanDisk, Samsung, Lexar, or Sony for reliability. Cheap no-name cards have higher failure rates.