How to Record Video with Action Cameras
- At least three action cameras.
- cameras may be of different models but must support one and the same pair of resolution and FPS
- All these cameras must be marked by some unique name/label to distinguish from each other.
- Optics of each camera must be calibrated.
It is almost the same as with web cameras:
- mount the cameras on tripods
- point the cameras that actor is fully visible in all cameras
- measure height of each camera over floor/ground
You can see example of scene set-up from the sample:
Four Important Things
When recording using action cameras there are four very important recommendations you have to follow:
- Use one and the same resolution and FPS on all cameras.
- After recording of scene calibration sequence cameras must be in totally stable position. In other case results of calibration become invalid.
- Video in each camera must contain a few seconds of clear scene (no actor, no moving objects, no glowing markers, etc.). It is required to evaluate background.
- Some short (visible exactly in one frame of video) event must be recorded in each video. It is required to synchronize videos from different cameras during creation of multi-camera video.
Uniform Resolution and FPS
Don't forget to set one and the same resolution and FPS for all cameras you're using during motion capture session.
Don't Touch Cameras
You shouldn't touch cameras after recording of scene calibration sequence till the end of all action recordings. There are two major options how to achieve this:
- use some remote control or smartphone application over Wi-Fi connection to start/stop recording
- or don't stop recording at all until the end of all action sequences.
The first option is preferable because it allows to save disk space and time required to copy and convert videos.
Don't forget to record clear scene in each camera. This is required to evaluate background.
When you're recording scene calibration video, it can be the moment when you turn on/off flash light (or Sony Move) which you use as a glowing marker. But be aware that flash light must be visible in all cameras at this moment.
When you're recording action video, you can also blink by flash light (or Sony Move). But we recommend to use external on-camera flash in manual mode like:
Use Test firing feature of your on-camera flash.
You can see an example of using such synchronization in the sample video: