Review: OM System OM-1 Micro Four Thirds Camera

OM System and Panasonic continue to breathe life into the Micro Four Thirds ecosystem, releasing well-received cameras like the Panasonic DC-G9 II and OM System OM-1. 

The 20-megapixel OM-1 offers five-axis image stabilisation, 120fps continuous shooting, subject detection and 4K video up to 60p. The camera does well to mitigate the limitations of its Micro Four Thirds sensor, with relatively strong low-light performance for its class.

MPB’s Connor Redmond visited New Forest Wildlife Park and Brighton Karting to test the OM-1's performance in animal and motorsport photography. In this review, Connor reveals the mirrorless Micro Four Thirds camera’s features and capabilities. Check out Connor’s photos from the OM-1 and his overall verdict.

OM System (formerly Olympus) released the OM-1 with both brands across the front—Olympus at the top and OM System on the bottom right. Subsequent cameras, like the OM System OM-1 Mark II, bear the OM System name alone. 

First and foremost, this is a Micro Four Thirds camera. This review will judge the OM-1 on its merits within its class. At 25% of the size of full-frame, Micro Four Thirds sensors gather less light and tend to offer poor depth of field and low-light performance. For many photographers, the size, weight and price benefits outweigh the compromise of the smaller sensor. And some wildlife photographers, for example, use the format’s 2.0x crop factor to simulate longer focal lengths at a much lower cost. 

The OM-1 offers some pretty impressive specs, with some disadvantages—but a greater number of advantages. 

Key Specifications

• 20-megapixel Micro Four Thirds quad-pixel sensor

• 5-axis image stabilisation up to 7 EV steps

• 120fps continuous shooting

• Subject detection-based autofocus

• 4K video up to 60p in 8-bit or 10-bit 

Pros

• Great selection of different multi-shot modes, taking great advantage of the In-body image stabilisation 

• Good image quality and dynamic range for Micro Four Thirds

• Low-light performance significantly improved 

Cons

• Not a lot of resolution to crop in

• Continuous autofocus is disappointing

Improvements

How has the OM-1 improved since 2020’s Olympus OM-D E-M10 Mark IV? In short, there’s a stacked sensor at 20 megapixels, which results in faster readout speeds, a critical feature for its target audience. You also have improved computational multi-shot modes, revamped subject detection autofocus, more frames per second and options for high-speed shooting.

Computational Multi-Shot

The OM-1 is packed with a range of genuinely useful computational multi-shot modes. You can access these modes in the ‘Shooting Menu’ screen.

1. High Resolution mode

The High Resolution mode captures eight shots while precisely shifting the sensor to create a single, ultra-high-resolution image. The image is up to 80 megapixels for RAW files and 50 megapixels for JPEGs. This mode is ideal for landscapes, architecture and product photography, but you’ll need a photo tripods.

2. Hand-held High Resolution mode

The OM-1’s Hand-held mode is similar to the High Resolution mode, but—as the name suggests—it’s designed for hand-held shooting. This mode is perfect for situations where a tripod is impractical, such as street photography or travel. No tripod required!

3. Live ND mode

Live ND mode simulates a neutral-density filter effect, through varying exposures and shutter speeds. The mode enables blur effects, like smooth water or light trails, in bright conditions without an ND filter. Live ND mode is useful for landscape, cityscape and long-exposures.

4. HDR (High Dynamic Range) mode

The camera’s HDR mode extends an image's dynamic range by capturing and combining multiple exposures. HDR mode helps to Preserve details in highlights and shadows. It’s ideal for high-contrast scenes, such as sunsets, backlit subjects or interior shots with bright windows.

5. Live Composite mode

Live Composite mode allows you to capture light trails—like star trails and vehicle light trails—while keeping the background elements static. The mode is useful for night photography, light painting and low-light scenarios with moving light sources.

6. Focus Stacking mode

The OM-1’s Focus Stacking mode stitches images with different planes of focus together to create an extremely sharp image. This mode is ideal for macro or product photography.

I found that all of these modes worked well and result in a good range of options. 

Need high-resolution images? You won't necessarily need to switch to full frame. The OM-1's High Resolution mode mitigates one of the drawbacks of Micro Four Thirds sensors. You can shoot at up to 80 megapixels, albeit using a tripod.

Subject Detection Auto-Focus

As is now becoming a standard feature, the OM-1 uses a Subject Detection Autofocus system that builds upon the capabilities of the Olympus OM-D E-M1X. 

The OM-1’s autofocus system uses ‘deep learning algorithms’ to recognise and accurately track a wide range of subjects. These include trains, cars, planes, helicopters, birds and animals.

High-Speed Shooting

The OM-1 is impressive when it comes to high-speed shooting. The electronic shutter—in its ‘Silent Sequential Shooting High mode’—can shoot a whopping 120 frames per second. With a readout speed of ~1/125th, the rolling shutter effect isn’t too bad. Predictably, you get a more reasonable 10 fps while shooting with the mechanical shutter. 

Shooting at 120fps, your autofocus will be locked at your first exposure. You can get continuous autofocus at 50fps, but only using some Pro-series lenses. With other lenses, including most Pro series primes, the maximum burst rate—with continuous autofocus—drops to 25 fps or lower. But that’s still rather impressive.

The relevant pro telephoto lenses are the PRO-series 12-40mm f/2.8 PRO, 40-150mm f/2.8 PRO, 300mm f/4 IS PRO, 7-14mm f/2.8 PRO, 8-25mm f/4 PRO ED and the 12-45mm f/4 PRO. These will allow you to unlock the OM-1 fully and shoot at 50fps with full continuous autofocus. 

The OM-1 can capture up to 92 RAW or JPEG frames in a single burst at the maximum speed of 120 fps (with the electronic shutter). The buffer capacity may vary depending on the selected shooting mode, image quality settings and memory card write speeds.

Despite its limitations, the OM-1's burst rate is still remarkable—particularly for a camera of this size and price. You certainly won’t be machine-gun shooting with it nonstop. But, for those key moments, the burst rate is fantastic. 

Body & Controls

Olympus cameras were made in Japan and had a reputation for reliability. While OM System has since moved production of its cameras to Vietnam, the OM-1 is equally robust and well-built.

Function Lever

The OM-1 retains the classic Olympus Function (Fn) Lever, a handy control that has been a staple of Olympus/OM System cameras for years. The Fn Lever is a two-position switch located near the shutter release button.

If you frequently adjust settings—like autofocus modes—during shoots, the Fn lever is particularly useful. While it only has two positions, the lever’s simplicity and direct access to customisable functions makes it a much-loved feature. 

Viewfinder and Screen

The OM-1 features an impressive OLED electronic viewfinder (EVF) and a fully articulating touchscreen, providing a high-quality viewing experience and versatile compositional options.

The EVF also boasts an impressive 120 fps refresh rate. This provides a smooth and lag-free viewing experience, even when tracking fast-moving subjects or panning the camera.

Improved Menu System

The OM-1's menu system features a cleaner and more intuitive layout than the Olympus E-M1 models. Like all menu systems, it takes a little bit of time to get used to its quirks. But overall, OM System has laid out their settings in an easy-to-understand way.  

Super Control Panel

With the Super Control Panel, you can change your camera settings without diving into the menu system. I liked how the control panel worked. 

Battery

The BLX-1 battery provides a power capacity of 2,280mAh. OM System claims to give a battery life of 520 shots per charge, when using the rear screen. I found the OM-1's battery lasted for most of a day's shooting, but I’d recommend getting a spare.

Image Quality

Other photographers have noted a difference in low-light RAW performance, with the OM-1 producing less noise and better colour rendering compared to its predecessors. I agree with this assessment. In fact, I think the OM-1 has the best low-light performance in any Micro Four Thirds camera I’ve used.

The increased dynamic range in RAW files is very welcome. While the sensor won't quite compete with APS-C or full-frame, the OM-1's image quality and dynamic range are excellent for its class.

However, the OM-1's colour rendition is unremarkable. You can dial in some colour information, but there's nothing particularly inspiring about the JPEGs or RAWs. This is no Canon or Fujifilm. Plus, I'm not a big fan of the bokeh—especially with the extreme telephoto lenses—it can look a little 'mushy'.

ISO Performance

The ISO performance was very good in most conditions. The noise reduction works well, and images shot from ISO 100 to 16,000 tend to not have much difference in them at all. 

Autofocus

While the subject tracking is good, the OM-1's continuous autofocus mode leaves a lot to be desired. I found that it jumps around the frame a lot and generally doesn’t hit focus on the subject you intended. Sony and Canon are far ahead. 

I had to manually assign the autofocus area most of the time. Usually it’s fine, but I’d expect better from a modern camera. 

Video

The OM-1 can record 4K video (4096x2160) at up to 60 frames per second. That’s now pretty standard. The camera supports 10-bit colour, which results in smoother gradations and more accurate colour reproduction, especially in scenes with subtle tonal variations. 

One of the OM-1's standout video features is its ability to output 12-bit RAW video over HDMI to external recorders and monitors like the Atomos Ninja V 4K or Atomos Ninja V+. This allows you to capture footage in the ProRes RAW format, which provides greater flexibility for colour grading, post-processing and dynamic range. But the downside is needing the extra gear—and media storage—to shoot better video, where many of its competitors can do more internally. 

Overall though, there are much better options if you’re looking for a more video-focused camera. The OM-1 doesn’t quite match the quality and features of Sony and Canon.

Olympus E-M1 III vs OM System OM-1 vs OM-1 II 

The OM-1 offers some improvements over the Olympus E-M1 III, while the OM System OM-1 Mark II is only marginally better than the OM-1. 

In all honesty, there isn’t that much difference between the OM-1 and OM-1 Mark II. The only physical difference is a rubber grip on the OM-1 Mark II, and slightly more RAM for a larger buffer. Otherwise, they’re pretty much the same camera physically.

The main difference lies in the software. So why didn’t OM System just release a firmware update to the OM-1? In any case, the update is all about firmware tricks. There’s an improved Live ND feature, graduated ND filters, improved autofocus, subject recognition and better IBIS (rated up to 8.5 stops). 

Is it worth the upgrade? Probably not. The OM-1’s updates are mostly focused on a niche set of features for wildlife photographers. It seems to me only an update for the most dedicated bird photographers who are already deep into the Olympus/OM System world.

Verdict

Are the size and weight worth the compromise in sensor size? Personally, I don’t think so. The balance of lens size and ‘reach’ is impressive, and I found it was a nice change to bulky full-frame lenses. However, I’d rather have better performance—even if it means a little more weight. 

If camera portability is your only reason to use Micro Four Thirds, full-frame cameras are catching up. For example, the full-frame Canon EOS R8 weighs 23% less than the OM-1. Although that’s not taking into account the weight of lenses, and Micro Four Thirds lenses tend to be lighter than their full-frame counterparts. In any case, I think it’ll be interesting to see where the Micro Four Thirds system goes next. 

Ultimately, the OM-1 is a camera with a relatively narrow appeal. It is built to excel at sports or wildlife photography—especially bird photography—while offering a genuinely small and lighter option than Canon, Nikon and Sony. If you have decided that Micro Four Thirds is the right system for you, then the OM System OM-1 is a great choice.