I considered posting this on other SE sites such as Audio-Video Production and Photography, but I didn't feel I'd get the definitive, fact-based (rather than experience-based) answer I'm seeking.
I used a GoPro HD Hero (which has a 170-degree view) to record a track day (driving a car) and a snowboarding trip. Playing back the videos after each event, I sensed immediately that they seemed slow. However, since clocks and speech seemed to progress at a normal rate, I dismissed my senses, figuring adrenaline and wind must've made me perceive real life faster than it actually was.
And there's probably some truth to this adrenaline-and-wind explanation, but watching the videos again today (more than a year later), I sensed the slowness as I always did. I came up with a potential, partial explanation, but still lacking; I was hoping someone might be able to shed some light as to whether this "slow video" phenomena is merely psychological, or an expected effect of optics.
I think there may be an effect, due to depth perception being altered by wide-angle lenses.
Suppose we were to record a skateboarder from the side, i.e. so the skateboarder would skate from left to right in our camera's field of view. In this case, because the axis of movement (the skateboarder's "line") would be perpendicular† to the axis of distortion (the camera's "line", or depth), there would be no distortion of perceived speed: the skateboarder moves relative to an undistorted frame of reference (the ground).
However, if we were to mount the camera on the skateboarder's helmet, i.e. record in a first-person view, then the axes of movement and distortion would be one and the same. From here though, I'm not sure how to explain why this translates to slower-seeming playback.
In layman's terms, my problem is, "The ground and the trees pass by me slower," when playing back a wide-angle video.
- Is this psychological, or is there a physical explanation?
- Is there a mathematical formula that can tell by how much one must speed up playback in order for "the ground and the trees" to pass by as they seemed to in real life?
† Technically, I guess "perpendicular" would be a curve, i.e. staying equidistant from the camera, but for simplicity, suppose the skateboarder is far enough from the lens that we may consider the curve a "line".