Action camera DJI Osmo Action 4 — 4K Ultra HD, CMOS sensor, 155° FOV, MicroSD up to 512 GB, waterproof 18 m, 145 g

DJI Osmo Action 4 is a compact action camera designed for high-resolution outdoor and underwater recording. It features a 1/1.3” CMOS sensor with a wide f/2.8 aperture and 2.4μm-equivalent pixel size to capture detailed images from sunrise to night. The camera records up to 4K UHD at 120 fps, supports a 155° ultra-wide field of view, and accepts MicroSD cards up to 512 GB. Lightweight and waterproof down to 18 m without an additional case, it includes dual touchscreens, magnetic quick-release mounting, native vertical shooting capability, and fast-charge battery support for extended use.

Advantages

Action 4 combines a large sensor and wide aperture for improved low-light performance and detailed footage, while 4K/120fps enables smooth slow motion. Dual water-resistant touchscreens and a magnetic quick-release system simplify framing and mounting. Native vertical shooting preserves full resolution for vertical content, and extended battery life with fast charging reduces downtime. The camera is rated for 18 m waterproof use and supports features such as timecode sync, GPS data recording, AI selfie stick removal, and Wi‑Fi livestreaming.

Suitable for

• Action sports and biking where high frame rates and stabilization are needed
• Underwater snorkeling and shallow diving up to 18 m
• Vlogging and social media content including vertical videos
• Multi-camera shoots requiring timecode synchronization
• Outdoor adventures in cold environments (down to −20 °C) with extended recording times

When it may not be suitable

While the camera offers broad versatility, professional cinema productions requiring larger sensors or interchangeable lenses may find its fixed wide-angle lens limiting. Also, if shooting deeper than 18 m or in extreme technical diving conditions, a dedicated underwater housing and equipment rated for greater depths are necessary.

Key specifications

• Image sensor: 1/1.3″ CMOS
• Aperture: f/2.8
• Effective pixel size: 2.4 μm (equivalent)
• Maximum video resolution: 3648 × 2736 (4K UHD)
• Frame rate: up to 120 fps (4K)
• Field of view: 155° ultra-wide
• Waterproof depth: up to 18 m without case
• Memory card: MicroSD support up to 512 GB
• Weight: 145 g
• Dual water-resistant touchscreens
• Fast-charging: up to 80% in ~18 minutes
• Low-temperature operation: recording down to −20 °C

How to use

Mount the camera using the magnetic quick-release or approved mounts, insert a compatible MicroSD card up to 512 GB, and power on. Choose resolution and frame rate (for example, 4K/120fps for slow motion) and select horizontal or native vertical mode using the protective frame. Use the front and rear touchscreens to change settings, preview shots, and start recording. For underwater use, ensure seals and ports are clean and the camera is rated for the intended depth. When livestreaming, connect via Wi‑Fi or a phone hotspot and use an external power source for long broadcasts. For multi-camera shoots, enable timecode sync and, if needed, pair the GPS Bluetooth remote to capture telemetry data.

What to consider before purchase

• Planned shooting depth (camera is waterproof to 18 m without a case)
• Need for interchangeable lenses or larger sensor for cinematic work
• Required storage capacity and MicroSD card speed for sustained 4K/120fps recording
• Compatibility with existing mounts and accessories (magnetic quick-release system)
• Battery life expectations and access to fast charging or external power for long sessions

Recommendations

Use high-speed UHS-II or UHS-I V60/V90 MicroSD cards for reliable 4K/120fps recording, enable timecode sync for multi-camera setups, and rinse the camera with fresh water after saltwater use. For vertical social-media content, use the native vertical shooting mode to avoid cropping and preserve full resolution.