Action Camera (GoPro, Insta360)

🟢 Start — zero knowledge, plain words. 🟡 Hands-on — building or buying, specifics and tradeoffs. 🔴 Specialist — the physics and math behind it.

🟢 Start. A separate camera "on the roof", independent of the FPV system: it records 4K/60+ to its own card while you mount it in a printed TPU cradle. The FPV camera shows; the action camera records — a division of labour, not a duplicate.

🟡 Hands-on. The FPV world often flies "naked" GoPros — stripped of case and battery (powered from the drone), because ~30 g instead of ~130 g makes a huge difference. Stabilization: built-in (HyperSmooth) or — more often — Gyroflow in post: the software takes raw footage plus a gyro log (from the camera or from the FC's blackbox) and stabilizes with full control, including horizon lock. ND filters force cinematic motion blur in sunlight.

🔴 Specialist. Mass costs non-linearly. From momentum theory $P_{hover} \propto m^{3/2}$: adding 120 g to a 650 g five-inch (+18% mass) raises hover power by $1.18^{1.5} \approx 1.29$ — +29%, not +18%. A higher center of mass also changes pitch response and demands a tune touch-up. Gyroflow under the hood: syncing the gyro log to frames, a lens-distortion profile, rolling-shutter correction — which is why the result beats in-camera stabilization, which never sees future frames.