Pick the wrong card and the camera drops frames mid-take. Pick the right one once and never think about it again.
Last reviewed on May 18, 2026.
Memory cards are the part of a video kit that buyers under-think and then regret. A card that's fast enough for a digital camera's stills mode may still drop frames in the same camera's 4K/120 video mode. A "high-speed" SD card on a packaging blurb may actually mean "high-speed for photos" — a different bar from sustained video write. This guide explains the labels, the gap between burst speed and sustained write, and how to map a camera's video specs to the card class it actually needs.
SD-card packaging usually lists three or four speed numbers — read speed, write speed, a UHS class, a Speed Class number, a Video Speed Class, and sometimes a Bus class. For video, only two of those actually decide whether your card keeps up:
The big read-speed numbers ("up to 200 MB/s") are mostly used for transferring footage from card to computer afterwards. They have almost nothing to do with whether the camera can write to the card without dropping frames.
Approximate minimum card classes for common video modes. Real cameras may require more — always defer to the manufacturer's specification sheet — but this is a reliable starting point:
| Video mode | Typical bitrate | Minimum card class | Comfortable choice |
|---|---|---|---|
| 1080p / Full HD up to 60 fps | ~50 Mbps | UHS-I U3 / V30 | Any reputable V30 SD |
| 4K up to 30 fps, standard bitrate | ~100 Mbps | UHS-I U3 / V30 | V30, ideally UHS-II |
| 4K 60 fps, 10-bit 4:2:2 | ~200 Mbps | UHS-II V60 | UHS-II V60 |
| 4K 120 fps | 200–400 Mbps | UHS-II V60 or V90 | V90 / CFexpress |
| 6K oversampled, ProRes-style codecs | 400–800 Mbps | V90 / CFexpress | CFexpress Type A/B |
| 8K RAW or 8K All-Intra | 800 Mbps+ | CFexpress Type B | CFexpress Type B, dedicated |
Why "comfortable" is sometimes a class above "minimum": camera vendors specify the minimum that just works under controlled conditions on day one. A card a class above gives headroom for higher bitrates that arrive in firmware updates, and for the small write-speed drop that happens as a card gets older.
UHS-I cards have a single row of contacts and a theoretical maximum bus speed of around 104 MB/s. UHS-II cards have a second row of contacts and reach 312 MB/s in compatible cameras. The visual giveaway: flip the card over — UHS-II has two rows of gold pins. If the camera reviewed on a body like the Sony ZV-E1 records 4K/60 or 4K/120, UHS-II is essentially mandatory; UHS-I will bottleneck.
V60 cards sustain at least 60 MB/s (≈480 Mbps), V90 cards at least 90 MB/s (≈720 Mbps). For most 4K work, V60 is enough. V90 becomes necessary as soon as 4K/120, ProRes, or All-Intra modes appear in the menu.
CFexpress is a separate, faster format. Type A is used by Sony in cameras like the FX3/FX30 line (and as an option in the a7S III / ZV-E1 ecosystem); Type B is used by Canon, Nikon, Panasonic, and most cinema cameras. The two are not interchangeable — they're physically different shapes. Type B is much faster (1700+ MB/s read on current cards), which is why 8K RAW capture sits firmly on Type B.
Action cameras, drones, and pocket cameras like the DJI Osmo Pocket 3 use microSD. The V-classes work identically to full-size SD — the difference is mechanical, not in the speed system. A V30 microSD is V30 in any camera that supports it. The catch: microSD cards run hotter and throttle more aggressively than full-size SD, so leave more headroom than you would with a regular SD card.
Drones tend to ship with manufacturer-recommended microSD card lists. Use them as the first filter. Consumer drones like the DJI Mini 4 Pro and Air 3S work fine with V30 microSD for 4K/30 and require V60 territory for their 4K/60 and higher modes. Cinema drones (Inspire 3, professional rigs) use proprietary SSD-style storage that bypasses the SD card system entirely. The drones shortlist indicates which storage class each model uses; the drone regulations page handles the legal side that's often more limiting than the technical one.
Capacity needs vary enormously by bitrate. Useful rules of thumb at common bitrates:
For a creator shooting all-day travel content at 4K/60, a 128GB or 256GB card is the sweet spot. For multi-camera or cinema work, 512GB and 1TB cards are now mainstream. Don't economise on a single huge card, though: a card failure on a 1TB card loses ten times as much footage as the same failure on a 128GB. Two 512GB cards is safer than one 1TB.
Storage is the third quiet upgrade — alongside audio and lens choice — that disproportionately determines whether a shoot day ends with usable footage. None of those three matter individually if the others are broken. Once the storage chain is sorted, the camera body itself (covered in the cameras shortlist) gets to do the job it was designed for.
If stabilisation is your next question, the stabilisation explainer covers IBIS, OIS, electronic stabilisation, and when a gimbal still belongs in the bag.