Gimbals are getting easier to buy, cheaper, and more companies are making them, but they're still less popular than drones. Nobody I know has used a gimbal so I couldn't get any advice. I went ahead and got my own, so here are the features you might want to look for when buying your own:
- Modes, in order of decreasing freedom of movement / increasing restriction:
Point Of View - allows movement in all 3 axes (tilt, pan and roll). Basically just smooths your hand movement.
Following - smooths tilt and pan movements only. Doesn't allow rolling, i.e. keeps horizon horizontal.
Pan Following - only allows pan movement.
Locked - keeps camera pointed in the same direction, to the best of the gimbal's ability. If you move the gimbal a lot in one direction, the camera keeps pointing parallel to its original direction. i.e. the camera behaves like it's on a slider.
(most restricted) Note: the instructions are not strictly accurate. e.g. they say in Locked mode, all axes motors are locked. Obviously this isn't true, or the gimbal would behave as a selfie stick. What they mean is the motors compensate for and negate movements in any axis.
- Vortex mode, where the camera rotates about the lens/roll axis. In my opinion, this effect isn't as nice as the professionally done one, because the rotation axis isn't aligned with the lens, so there's another form of movement in the video. Vortex mode requires:
- Pan axis rotation. My gimbal says it's 360°, but it's really infinite rotation, which is much more impressive, because it has to have a slip ring system in there. Especially since the pan axis is the first motor, and all the connections to the other motors have to pass through the slip ring.
- Independent functions. I'm talking about what the gimbal can do standalone, without any connection or app. Because this way you can use it with any other app, or even other devices. Like making video calls. My gimbal can use all the above modes standalone. Actually the app doesn't seem to add that much functionality.
- Selfie mode - rotates the phone 180° to face you. Useful if you want to use the back camera for selfies.
- 90° mode - smartphone gimbals are usually designed to shoot horizontal video when holding the gimbal vertically, i.e. the phone is perpendicular to the gimbal, like a T. If you shoot a lot of vertical videos or streams, you might one that can quickly rotate or at least hold the phone vertically, parallel to the handle. Mine doesn't really do this, but it has a pseudo-90° mode where you can hold the handle horizontally and it stabilises the phone vertically.
- Tracking - this is probably the most important/useful function of gimbals, and it requires the app. You mark an object in the video and the gimbal tries to keep the camera pointed at it as the object/camera move. Obviously strongly dependent on how well it separates the object from the background, especially as the perspective of the object changes. You might put the gimbal on a table and have it track you as you walk around. Sort of like a security camera. You might track a model/building as you circle around it.
- Movement range of the gimbal. An important feature to look out for. As I said, mine can pan infinitely, but the movement range in other axes isn't so good. Actually the specifications are fine, but due to the small gimbal/large phone, the phone keeps obstructing the gimbal from moving freely. Another limitation is that its movement range allows it to hold the phone vertically, but it just isn't programmed to do so. If you want to do complicated movements, maybe start looking at a standing person's feet, scrolling up their body to the top of their head, then down the back of their body, you need to look at what the gimbal can and cannot do.
- Panorama mode. Controlled by the app, the gimbal moves to different angles and takes pictures, then stitches them into a panorama. Seems like this would be a good task for gimbals but they all seem slower than doing this by hand.