SJCAM SJ30 vs SJCAM C400
In short: The SJCAM C400 costs $30 less; the SJCAM SJ30 collects light over 31 mm² against 18, which is 1.7× the area; the SJCAM SJ30 is waterproof to 5 m bare and the SJCAM C400 is not waterproof on its own at all; only the SJCAM SJ30 has horizon lock; the SJCAM C400 claims 7 h 17 min at 4K30 with the 3000 mAh handle attached; 172 minutes on the 54 g camera alone.
| Spec | SJCAM SJ30 | SJCAM C400 |
|---|---|---|
| Approx. price | ~$259 | ~$229 |
| Year-one cost | ~$259 | ~$229 |
| Type | Budget action | Budget action |
| Sensor size | 1/2-inch | 1/2.8-inch |
| Sensor area | 31 mm² | 18 mm² |
| Max resolution | 8K @ 20fps | 4K @ 30fps |
| Reframed resolution | n/a — already flat | n/a — already flat |
| Max fps at 4K | 60 | 30 |
| Max fps at 1080p | 240 | 120 |
| Max bitrate | Not published | Not published |
| Colour depth | Not published | Not published |
| Log profile | None | None |
| Stabilisation | SteadyMotion 2.0 | 6-axis gyro EIS |
| Horizon lock | 45° (lean only) | None |
| Aperture | f/2.8 | f/2 |
| Waterproof | 5 m bare, 30 m cased | 30 m in the case only |
| Claimed runtime | 7 h at 4K30 with the 4200 mAh power handle attached | 7 h 17 min at 4K30 with the 3000 mAh handle attached; 172 minutes on the 54 g camera alone |
| Tested runtime | No third-party test collected | No third-party test collected |
| Battery | 2000 mAh | 1250 mAh |
| Cold rating | -4°F | — |
| Weight | 162 g | 54 g |
| Screens | Flip rear touch + front display | Rotating screen on the handle |
| Mount | GoPro folding fingers | GoPro folding fingers |
| Replaceable lenses | No | No |
| GPS | No | No |
| Voice control | Yes | No |
| Storage | microSD | microSD |
| Subscription | None | None |
| Released | 2026 | 2025 |
A highlighted cell is the outright better figure in that row, and only where one direction is unambiguously better. Weight, field of view and battery capacity are left neutral because the better direction depends entirely on what you are shooting.
Strengths and drawbacks
SJCAM SJ30
- +Seven hours at 4K30 with the handle, second only to SJCAM's own C400 here
- +Two lenses with separate imaging chips, a real day-and-night system
- +5 m of bare waterproofing with no case
- +45° horizon lock, which most budget cameras omit entirely
- −The 8K mode runs at 20 fps, below the frame rate that reads as motion
- −45° horizon lock corrects lean but not rotation, unlike a 360° lock
- −Launched in 2026, so there is no owner track record yet
- −Dual lenses mean two lens surfaces to scratch, neither of them replaceable
SJCAM C400
- +Over seven hours at 4K30 with the handle, the longest figure in this catalogue
- +54 g module is lighter than a GoPro HERO and close to an Insta360 GO 3S
- +Rotating screen makes it usable for talking to camera
- +About half the price of the Insta360 GO Ultra it copies, and well under the DJI Osmo Nano
- +The camera module drops into the handle without a cable, so the changeover takes seconds
- −1/2.8-inch sensor — a quarter of the Osmo Nano's imaging area
- −No bare waterproofing at all
- −4K30 only, no horizon lock, no log profile
- −The module has no screen of its own; framing needs the handle