Can anyone explain the effect of zoom on speed perception with video?

Scuzi · 31 Oct 2009 at 23:03

A random question I know but whenever you watch the likes of Cops or any of the police TV shows it's noticeable.

Lets say the police car is travelling at 70mph and the camera inside the care is at a wide zoom angle. The perception of speed is quite high, i.e. the car appears to be travelling fast.
However, when the camera is zoomed in, the perception of speed is massively reduced. The car appears to slow down significantly where in fact it hasn't changed speed at all. when the camera zooms back out, the car appears to be travelling fast again.

I'm sure there's a logical explanation for this but I can't work it out. Can anyone explain it in simple terms?

Irish_Tom · 31 Oct 2009 at 23:16

I guess it's due to some form of relativity.

When the camera angle is wide, you see more 'background' flying past at high speed.

When the angle is narrow, and focused on a target moving at the same speed as the pursuit vehicle, the relative speed is less.

That's the only thing that comes to mind.

Panzer

Zefan · 31 Oct 2009 at 23:28

It's because things far away appear to be moving slowly relative to the things nearer you.

asim18 · 1 Nov 2009 at 00:05

Its because with a wide field of view you can see things to your left and right whizzing past.

With a narrow field of view you can only see a central part of the image, a smaller point which is directly in front of you, without any sides.

Your brain doesnt process any thing on the left and right whizzing past, only the central thing which is in tight focus.

Adrianr · 1 Nov 2009 at 10:22

Zefan said:
It's because things far away appear to be moving slowly relative to the things nearer you.

This. Wide view shows things near you, Zoom view doesn't.

Phate · 1 Nov 2009 at 11:53

I would've said it was something to do with distortion. On a wide angle lens to the sides it stretches so as you move the camera things seem to enter and exit the viewfinder faster due to the distortion.

laiman · 2 Nov 2009 at 13:17

Its been well explained above but think about it the same as when your actually in a car, if you look out the side windows you seem to be racing along but if you look through the windscreen your speed appears much less.