Strange object captured over Malvern Hills, Western England - Reddit

[Z.W. Wolf]

They also don't appear to note how it travels on a curving path.

Right. They show how a straight line can be curved by a rolling shutter. Not how a wobbling arrow can show up as a mostly straight arrow.

Also, we're looking for zebras instead of horses. How likely is it that some guy will randomly capture an arrow passing a few feet over his head versus an insect or a plant part? C'mon.

 

[Z.W. Wolf]

There are two types of oscillation involved:

https://www.bow-international.com/features/dynamic-behaviour-of-arrows/#:~:text=That is, the fletching is,with its direction of travel.

... the fletching is used to minimize oscillation in pitch and yaw (or in archery terms, to minimize porpoising and fishtailing).

Seems that would be a complicated motion. Would the shape of the arrow be so consistent across the entire frame? Even as the oscillation was changing?

Also, I've found lots of examples of straight shapes - in motion - that are distorted into curved shapes. But I can't find any image of a curved shape distorted into a (mostly) straight shape.

This was caused by a true rolling shutter on a film camera rather than a "rolling shutter" on a digital camera.

But... the rolling shutter really = the exposure timing pattern. Not the physical shutter.

A old fashioned cloth curtain focal-plane shutter at high speeds creates a rolling shutter exposure.

A visual example. This is an old focal plane shutter with a horizontal timing pattern.



You can see how the bottom of the tires was exposed first and the top afterward. The top of the tires had moved on by that time.

 

[Mendel]

The superposition that Mick posted in post #5 completely rules out an arrow, because it requires that the tip of the arrow and the tail of the arrow move on parallel paths that never cross.

 

[KalleMP]

I wonder if it (grass, pine needle, seed) was launched into the air stuck to the frizbee with some dog saliva and had some elevation and momentum imparted to it.

Is there some equation that will determine at what distances a small object can be resolved with a camera based on point of focus, size of object and distance from camera (for some given camera and lens)? Perhaps it fell of the disk but was too small to resolve, then drifted in the wind until it came close enough to resolve even though it was out of focus.

Kalle
--
Helsinki, Finland