SJCAM action and 360 cameras

SJCAM carried the SJ20's two-lens idea forward and gave each lens its own sensor and processing path — a 1/2-inch daylight sensor, and a 1/1.8-inch starlight sensor behind an f/1.8 lens for night — which is a more serious piece of engineering than the price suggests. The headline is 8K, and the honest reading of it is 8K at 20 fps — below the 24 fps that reads as motion, so it is a stills-adjacent mode rather than a usable video one; 4K60 is the real ceiling. What is unambiguously good is endurance: a 2000 mAh internal cell plus a 4200 mAh power handle gives a claimed seven hours at 4K30, which only SJCAM's own C400 beats here. Horizon lock is the 45-degree kind, which corrects lean but not rotation.

A pocket-shaped body rather than a GoPro-shaped one, and the whole design is organised around recording for hours: a 1000 mAh camera battery that clips into a 2800 mAh grip, for a claimed six hours at 4K30. That makes it a body-cam and vlogging tool more than a sports camera, which is how SJCAM markets it. Dual touch screens, six-axis gyro stabilisation, a 30 m case. The limits are the usual ones at $159 — 4K30 with no horizon lock, no bare waterproofing, and no published bitrate — plus a form factor that does not sit as well on a helmet as a standard action-camera body does.

SJCAM has been building GoPro-shaped cameras longer than most of the brands that undercut it, and the SJ11 Active is its mainstream model: a Sony sensor behind an Ambarella processor, dual screens, 5 m of bare waterproofing and 30 m in the case. At roughly 18 mm² its sensor is among the smallest in this catalogue, which matters more than the 20 MP on the box. Where it does well is the dual-screen layout and a 4K30 image that holds together in daylight. Slow motion is 1080p120, there is no horizon lock, and SJCAM rates the 1300 mAh battery at 100 minutes of 4K30.

Two lenses on the front, and neither of them is for 360 capture. One is an f/2.0 daylight lens; the other is an f/1.3 night lens, and the camera switches between them. It and the newer SJ30 are the only cameras in this catalogue that answer low light with a second, faster lens rather than a bigger sensor or noise reduction, and for night riding or filming from a car that is a genuinely different answer. The cost shows up everywhere else: each lens sits on a small 1/2.8-inch sensor, 4K stops at 30 fps, the bitrate is 25 Mbps — the lowest figure in this catalogue, and low enough that fast motion visibly falls apart — and there is no horizon lock. It did surprise on endurance: in road.cc's four-camera drain test it stopped within three minutes of the DJI Osmo Action 5 Pro, about half an hour after the Insta360 Ace Pro 2.

A 54 g camera module that drops into a handle carrying a 3000 mAh battery and a big rotating screen — the same split-body idea as the DJI Osmo Nano and Insta360 GO Ultra, executed for well under their price. Seven hours and seventeen minutes at 4K30 with the handle attached is the number SJCAM leads with, and only its own SJ30 comes close. What it does not have is the sensor those two carry: 1/2.8-inch against their 1/1.3-inch and 1/1.28-inch, a quarter of the imaging area, which is the whole difference in low light. Nor is there bare waterproofing. Read this as a very long-running vlogging camera rather than a small flagship.