At what HZ does the eye see?

Short answer:

It doesn’t, and it doesn’t matter how high fps you have, you can always do better.

Long answer:

Go outside, look straight ahead. Hold up one finger in front of your face and move it rapidly from side to side. The finger is blurry.
Now do the same thing, but instead of looking straight ahead, look at the finger. Notice how the background is blurry instead of your finger?

Now say that instead of being outside in the real world, you were inside in a cinema, watching a movie of a finger moving rapidly from the left to the right. Say the finger moves one full cycle in one second. Normal cinema runs at about 24 frames per second, so instead of seeing a single blurred finger along the entire screen, you’d see a focused finger in 24 unique locations.
To solve this, we can add motion blur to the finger, but then the finger will no longer look sharp when you follow it with your eyes.

(The next time you’re watching a movie in cinemas, pay extra close attention to the background when the camera pans. Horrible, isn’t it?)

If we were to speed up the movie ten times, the finger would be in 240 unique locations, or would be blurred 1/10'th of the 24 hz version, but it’s still not perfect.

This is the reason flourescent lighting is HORRIBLE. When looking straight ahead at a stationary object, you probably can’t tell what type of lighting there is, but as soon as you move your eyes, or something in the room moves, there is a strobe effect (even if faint) that breaks up motion.

When in doubt, wave your hand in front of your face and check if you see a smooth blurred hand or a series of “snapshots” of the hand. If your hand isn’t smooth, nothing lit by that lightsource will be smooth.


The next time someone tells you the eye can’t see more than 30 fps, stab them in the face with a screwdriver.

posted 14 years ago