A thought on photography.
Light is fast.
Think of those toys with a cardboard disc with a picture of a bike on one side and the rider on the other, and hopes for string at the sides. You pull the string and that rider is suddenly on the bike. The rapid movement doesn't let enough light hit your eye if either side, so they appear transparent.
Just wave your hand in front of your face really fast, it basically disappears.
A good camera picture needs a lot of light to bounce off the subject.
If the camera is going fast and of lower quality, like video, and the subject is moving fast, possibly lower light conditions due to clouds, not as much light gets to the camera.
The actual time of the frame shot has movement, so that allows the background with stronger light emitting from it to take presidence over the lower light of the moving object.
That's why legs blur on runners and spoked wheels disappear at speed.
This could cause things to disappear, especially if they are only there for one or two frames.
Just a thought to those wondering.
