Achieving smooth video footage is essential to being able to create good videos. But smaller and lighter radio controlled aircraft are more susceptible to air turbulence which results in frequent deflections along each of it's three main axes (pitch, roll and yaw) that can make video footage appear 'jerky' and in many cases uncomfortable to watch. This can be most evident when the camera is directly attached to the aircraft. Flying when there is little or no wind helps a great deal, but even then, small changes in air pressure can translate to unstable video footage. Some form of video stabilisation can in most cases help create smooth video footage. The videos below illustrate some of the methods used and the resulting footage, starting with an example where no stabilisation is used.
No video stabilisation
The video below was taken using a Mobius Actioncam directly mounted on the nose of the Mini Skywalker plane. The camera was hard mounted to the plane so any movement the plane makes in flight is translated directly into the video. Although it was a very calm morning there is still a significant amount of movement as the plane itself is small and quite light. In some parts of the video you can see a small amount of waviness, often referred to as 'jello', and arises due to vibrations from the motor. These vibrations can often be reduced or eliminated by strengthening the motor mount and adding a foam damper between the camera and the plane.
Stabilisation using a camera gimbal
This video was taken using a camera gimbal to stabilize the video footage. A 2-axis gimbal was used that compensates for movement around the roll and pitch axes. The gimabl has been built into a pod that can be mounted at the front of the aircraft. The short video below shows it in operation.
The gimbal pod was made to be fitted onto the front of a full-size Skywalker airframe capable of taking the additional weight of gimbal. With a wing-span of 1.8m and a flying weight of a couple of kilograms, it is less susceptible to turbulence but still requires the gimbal to provide smooth video footage which is demonstrated in the clip below.
In-camera stabilisation
More recently, advanced sports action cameras provide the ability for the image to be stabilised in the camera itself. It does this by capturing an image that is bigger than the resulting image, and using the resulting margin and a built-in gyro, adjust the image to compensate for any short term disturbances to the pitch, roll and yaw axes. Some cameras process these adjustments in the camera itself, while others record the gyro information alongside the video and then process the video in software on a computer. The advantage of this latter approach is that the camera need not include the processing power, and hence the weight (including the additional battery power) needed to process the image.
The video below shows a side-by-side comparison of both original and stabilised clips that gives an idea of the degree of correction that can be achieved. The video was taken with an Insta360 SMO 4k camera on a ZOHD Nano Talon with a flight controller that had not been tuned resulting in it flying poorly.