OM SYSTEM OM-1 Mark I
The Olympus Mark I is a 20.4MP Micro Four Thirds mirrorless camera — with 4K video and in-body stabilization. Check GearFocus for current availability, with buyer protection on every purchase.
OM SYSTEM OM-1 Mark I
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Camera Overview — Olympus Mark I
Key Features — Olympus Mark I
20.4MP MFT Sensor: Micro Four Thirds format with a 2x crop factor pairs well with a wide range of native lenses for wildlife, sports, and travel photography.
TruePic IX Processor: OM SYSTEM's flagship image processor enables fast readout speeds, computational features, and the high burst rates the OM-1 is known for.
5-Axis In-Body Stabilization: Optical IBIS with up to 7 stops of compensation (8 stops when paired with compatible lenses) keeps handheld shots sharp across stills and video.
20fps Mechanical Burst: Continuous shooting at up to 20fps with the mechanical shutter, with high frame rate options at lower resolutions via electronic shutter.
Quad-Pixel Phase Detection AF: All 20.4 million pixels function as phase-detection points, delivering fast, reliable subject acquisition with eye, face, and animal tracking built in.
4K/60fps Video with OM-Log: Records 4K video at up to 60fps and includes OM-Log and Flat color profiles for greater dynamic range and flexibility in post-production.
Camera Specifications — Olympus Mark I
| Spec | Detail |
|---|---|
| Use Cases | Portrait, Landscape, Travel, Street, Studio |
| Type | Mirrorless |
| Sensor | Micro Four Thirds (MFT) |
| Resolution | 20.4MP |
| Processor | TruePic IX |
| ISO Range | 200 – 25600 |
| AF System | Quad Pixel AF, Eye Detection AF, Face Detection AF, Animal Detection AF, AI-Based Subject Tracking |
| AF Points | 121 |
| Max Photo Resolution | 5184x3888 |
| Burst Rate | 20 fps |
| Max Video Resolution | 4K |
| Max Frame Rate | 60fps |
Description — Olympus Mark I
The OM SYSTEM OM-1 Mark I is a Micro Four Thirds mirrorless camera powered by a 20.4MP sensor and the TruePic IX image processor. It operates across an ISO range of 200 to 25600 and delivers continuous shooting at up to 20fps, supported by a multi-system autofocus setup combining Phase Detection, Contrast Detection, Eye Detection AF, and Face Detection AF across 121 focus points with subject tracking enabled. The 5-Axis In-Body Image Stabilization works at the sensor level without digital processing.
For video, the OM-1 Mark I captures 4K footage at 24fps, 30fps, or 60fps, with OM-Log and Flat color profiles available. The 3-inch LCD display resolves at 1.04M dots, while the electronic viewfinder offers 2.36M dots at a 120fps refresh rate. The magnesium alloy body measures 134 x 91 x 69mm, weighs 599g, and is rated weather sealed.
Storage uses SD, SDHC, and SDXC cards. Connectivity covers Wi-Fi, Bluetooth, USB-C, Micro HDMI, and 3.5mm headphone and microphone jacks. The BLH-1 battery is rated at 440 shots per charge.
Pros — Olympus Mark I
- ✓5-Axis In-Body Image Stabilization provides optical steadiness (imageStabilization.type: '5-Axis In-Body Stabilization')
- ✓Fast 20fps burst mode suits action and wildlife shooting (photoSpecs.maxBurstFrameRate: 20)
- ✓Comprehensive autofocus with Phase Detection, Contrast Detection, Eye Detection, Face Detection, and subject tracking (autofocus.system)
Cons — Olympus Mark I
- ✗ISO minimum of 200 is higher than some competitors, limiting dynamic range headroom in bright conditions (iso.min: 200)
- ✗Electronic viewfinder resolution of 2.36M dots is modest compared to higher-end mirrorless options (viewfinder.resolution: '2.36M dots')
- ✗Single card slot with SD/SDHC/SDXC only — no redundant backup storage (storageMedia)
Videos — Olympus Mark I
OM System OM-1 Final Review — DPReview TV
Frequently Asked Questions — Olympus Mark I
What lens mount does the OM SYSTEM OM-1 Mark I use?+
The OM-1 Mark I uses the Micro Four Thirds lens mount, giving access to the broad range of lenses built around that standard. The mount information is listed explicitly in the specifications under mount.lens.
Does the OM-1 Mark I have in-body image stabilization?+
Yes, the camera features 5-Axis In-Body Image Stabilization, as listed under imageStabilization.type. The digital IS option is not active (digitalIS: false), meaning stabilization is purely optical/mechanical.
What video specifications does the OM-1 Mark I support?+
The camera records up to 4K resolution at frame rates of 24fps, 30fps, and 60fps. Color profiles available for video include OM-Log and Flat, which are useful for grading in post-production.
Is the OM-1 Mark I weather sealed?+
Yes, the body carries a weather-sealed rating and is constructed from magnesium alloy, as specified under bodyDesign.weatherSealing and bodyDesign.material. This makes it suitable for use in challenging outdoor conditions.
What autofocus features does the OM-1 Mark I offer?+
The autofocus system includes Phase Detection, Contrast Detection, Eye Detection AF, and Face Detection AF, with 121 focus points, eye tracking, and subject tracking all confirmed in the specifications under the autofocus section.
What connectivity options are available on the OM-1 Mark I?+
The camera offers Wi-Fi, Bluetooth, USB-C, standard USB, Micro HDMI output, a 3.5mm headphone jack, and a 3.5mm microphone jack. The hot shoe is Olympus Standard TTL, accommodating compatible flash units.