Choosing an SD Card for the OM-1 and OM-1 Mark II

The Olympus OM-1 (and its newer successor, the OM System OM-1 Mark II) do not come with memory cards in the box. Even if your camera arrived as part of a retailer bundle, the included card is often too small and too slow to keep up with the camera’s high-speed bursts or video features.

But what type of memory card should you get?

The short version: a full-size UHS-II SDXC card rated V60, somewhere in the 256GB to 512GB range, covers everything either body can do. V90 costs more and only earns its keep if you shoot long RAW bursts back to back. A UHS-I V30 card will still record the heaviest 4K video these cameras shoot, but it slows down how fast the camera empties its buffer.

This guide cuts through the technical jargon so you can get out shooting sooner. I have been testing SD cards for years, and the recommendations below focus on practical performance. Because neither of these cameras requires the absolute fastest memory cards on the market, overpaying for peak speed is a waste of money. While a top-tier card might speed up the process of offloading images to a computer with a fast reader, it offers absolutely no in-camera performance benefit.

You can see some of the real-world results I’ve gotten with this system in these posts:

– Olympus OM-1 Sample Images
– Olympus OM-1 High ISO Sample Images

Quick recommendations

If you just want a quick answer, any of the cards below will work flawlessly in either the OM-1 or OM-1 Mark II. They meet the technical demands of the camera, have a strong track record of reliability, and offer the best performance-to-price ratio based on my independent SD card speed tests.

A Quick Note on Naming: I refer to the original camera here as the Olympus OM-1 because it carries the Olympus name on the front, but the company is now officially OM System (the same naming situation applies to the OM System OM-5). The sequel is properly named the OM System OM-1 Mark II.

Compatibility & technical requirements

Both the OM-1 and the OM-1 Mark II feature dual SD card slots. Both of these slots are built around the faster UHS-II interface, and both are fully backward compatible with standard SDXC and SDHC cards. (Just avoid the newer SDUC or SD Express formats, as the camera cannot utilize them).

That’s worth spelling out if you’re coming from an E-M1 Mark II or Mark III, where only slot 1 had the UHS-II pins and a UHS-II card dropped to UHS-I speed in slot 2. On the OM-1 and OM-1 Mark II there’s no slow slot, so it doesn’t matter which slot your faster card goes in.

Both slots take full-size SD cards, not microSD. A microSD card in a full-size adapter will physically fit and work, but almost every adapter sold has only the single row of pins, so even a UHS-II microSD card runs at UHS-I speeds in one — which puts you right back into the buffer bottleneck. If you already own microSD cards, keep them for the drone or the action camera and buy full-size cards for this body.

Because the slots are backward compatible, you might be wondering if you actually need to buy a more expensive UHS-II card. Strictly speaking, no. You can put an older, slower UHS-I card into either slot, and the camera will power on and take photos perfectly fine.

In fact, the highest technical hurdle for video on these cameras is a maximum bitrate of 202 Mbps when shooting 4K or C4K at the fastest framerates.

Because 202 Megabits per second equals roughly 25 Megabytes per second, a standard UHS-I V30 card is technically capable of recording the camera’s heaviest video files without dropping frames. If you are only shooting casual video or single-shot travel photos, overpaying for peak speed is a waste of money.

However, I strongly recommend using UHS-II cards in this system if you plan on shooting action. The OM-1 series is built for incredible speed, capable of rattling off RAW bursts at 50 to 120 frames per second.

If you pair that kind of continuous shooting with a slower UHS-I card, you are effectively bottlenecking the hardware. The camera’s internal buffer will fill up almost immediately during a rapid-fire sequence, leaving you stuck waiting for the camera to slowly offload those heavy RAW files before you can fire the shutter again.

The two bodies aren’t equal here. OM System’s figures put the Mark II at about 256 RAW frames at 50 fps and 213 frames at its 120 fps setting, roughly double the original OM-1, which runs out at around 92 frames at its fastest rate. A card can’t make the buffer deeper, but the Mark II’s deeper buffer means there’s twice as much data waiting to be written when the burst ends, so the card’s write speed is what decides how long you stand there waiting.

The upshot is that upgrading to a UHS-II card allows the camera to clear its internal buffer quickly, keeping you ready for the next burst. You need a fast SD card to unlock the camera’s true potential, but as we’ll see below, you still don’t necessarily need the fastest, most expensive V90 cards money can buy.

Hardware Warning: Avoid the newer SD Express or SDUC cards. The OM-1 bodies do not have the internal interface required to utilize them, meaning you will pay a massive premium only to have the card drop back to UHS-I speeds — slower than a UHS-II card that costs less.

What the OM-1 manual says

If you go looking in the manual, you’ll find these recommendations in relation to compatible memory cards:

• The following types of SD memory card (commercially available) can be used with this camera: SD, SDHC, and SDXC.
• When recording movies, use an SD card that supports an SD speed class of 10 or higher.
• A UHS-II or UHS-I card with a UHS speed class of 3 or better is required when: a movie resolution of [4K] or [C4K] is selected . . .

There is an official SD card compatibility table for the OM-1, but it’s quite limited (only SanDisk and Toshiba cards) and hasn’t been updated for the newest cards.

Do you need to fill both slots?

No, the camera will function perfectly fine with a single memory card in Slot 1. However, utilizing both slots gives you excellent data management flexibility in the field. I’ve covered where these slot settings live in the menus separately. Depending on the shoot, you can set the camera to:

• Standard/Overflow: Record to one card, automatically rolling over to the second card when the first is full.
• Dual Independent: Save high-resolution RAW files to your primary card, while sending smaller JPEGs to the second card.
• Backup/Dual Same: Write duplicate versions of the exact same file to both cards simultaneously as a real-time fail-safe. If you use this method, you should buy two identical memory cards. Because the processor cannot clear the internal buffer until the file is written to both locations, the camera will always bottleneck to the speed of the slowest card. Pairing a premium V90 card with a budget V30 card here will instantly throttle your burst speed to match the slower card.

Decoding the SD card jargon

Memory cards are covered in cryptic acronyms. Here is exactly what matters for the OM-1 series, and what you can safely ignore.

• SDHC vs SDXC: This simply denotes the file system and capacity. SDHC covers cards up to 32GB, while SDXC covers cards 64GB and larger. The OM-1 is fully compatible with both.
• UHS-I vs UHS-II: This refers to the physical pins on the card. UHS-II cards have a second row of pins that allow for much faster data transfer. Because both slots on the OM-1 are UHS-II, a UHS-II card is what lets the camera clear its buffer at full speed. UHS-I cards still work, and a V30 UHS-I card handles even the heaviest video these cameras shoot, but it caps how quickly the camera recovers after a long burst.
• Video Speed Class (V-Rating): This is the most important metric. A V60 card sustains 60 MB/s, which provides plenty of headroom for the OM-1’s maximum 4K video bitrate. A V90 card sustains 90 MB/s; it is overkill for the video features, but offers the absolute fastest buffer-clearing performance for wildlife or sports photographers shooting massive RAW bursts.
• A1 or A2: Ignore this entirely. It is a metric for how well a card runs smartphone and gaming apps, and has zero impact on a camera’s performance.

What Size SD Card should you buy?

The OM-1 is compatible with capacities ranging from 4GB all the way up to 2TB.

For modern shooters, the sweet spot for convenience and price is usually between 256GB and 512GB. This gives you plenty of room for heavy 4K video files or a long weekend of RAW burst photography without forcing you to constantly dump your files to a hard drive.

Formatting & card prep

It’s best practice to always format your SD cards inside the OM-1 before a new shoot. This ensures the filesystem and folder hierarchy are perfectly matched to the camera, greatly reducing the risk of file corruption.

If you do a standard format in-camera, it simply rebuilds the file table. If you accidentally format the wrong card, you can still usually recover your deleted photos using recovery software.

However, if your card starts acting sluggishly or the camera’s buffer hangs unexpectedly, the flash memory sectors might be fragmented. At that point, you should connect the card to your computer and learn how to use a utility tool to execute a full format vs a quick format to completely wipe and restore the drive to factory performance.

One more number to be careful with: the big MB/s figure printed on the front of the package is almost always the card’s peak read speed, which only matters when you’re copying files off the card. Sustained write speed is what determines how fast the OM-1 clears its buffer, and the V rating is the only write figure the card is actually guaranteed to hold. A card advertised at 300 MB/s and a card advertised at 170 MB/s can be identical in the camera if they carry the same V rating.