2007-03-07 12:20:26 · 18 answers · asked by g0th_k1d666 1 in Science & Mathematics ➔ Alternative ➔ Other - Alternative
depends on the wavelenghts of light and reflected by light
vision is a learned skill is also a dynamic process,; constantly adapts as we move and as illumination levels change, light is captured by the brain to give us the sense of vision, light has a direction, an intensity, a polarization, and that it comes in wavelengths (colors). within every light source is a combination of wavelengths of light. These wavelengths correspond to what we perceive to be colors. The short wavelengths are the blue, indigo, and violet end of the spectrum. The long wavelengths are the red, orange, and yellow ends. The human eye (central vision) is most sensitive to the wavelength corresponding to yellow. Yellow is the most "seeable" wavelength.
2007-03-07 13:26:45 · answer #1 · answered by Byzantino 7 · 3⤊ 1⤋
The answer is dependent on the situation. If you are in a dark room using a strong high speed strobe light you can easily see an event that lasts less that 1/1,000 of a second. The signal takes much longer to reach the brain and even longer for the brain to decide what it saw.
The idea that a person can only see at less that 1/25 of a second is due to the brain "filling in the gaps". As evidence of this you can look to the theater industry in the early to mid 1960s. Many theaters would replace single frames in a film with a picture of popcorn, Mike-n-Ikes, or (fill in your favorite) and they often saw an increase in sales of that product. The practice is referred to as "Subliminal Advertising" and has been banned by law.
So... normally we see at about 20 frames a second, but under special circumstances (adrenalin rush, strobe light, etc) we can see much faster.
2007-03-09 01:51:57 · answer #2 · answered by Balddragn 2 · 1⤊ 0⤋
Ever looked at the sun and then looked away? It takes about a second or more for the visual system to recover, right?
So, the speed of visual detection is dependent on the intensity of light. When we look at the sun it's an extreme case of saturation/overload and that's not indicative of normal viewing conditions.
When you go to the movies you only see 24 frames per second. With the intense light and the slow damping speed of the eye this is enough to ensure smooth perceived motion.
So, at higher light intensities (but below saturation) the reaction time of the visual system is LONGER than 1/24th of a second.
At lower light levels faster updates are needed, so the TV sets run at 25 (Europe) to 30 (US) INTERLACED frames per second.
2007-03-08 14:24:05 · answer #3 · answered by Andre P 3 · 3⤊ 0⤋
Our eyes are receptors of light which travels at a constant speed. However the moment of awareness of seeing varies from person to person. You can look at this question another way if you see a star 4 light years away it has taken you 4 years to see it
2007-03-08 18:18:57 · answer #4 · answered by des_wilms 2 · 1⤊ 0⤋
The signals get to our retinas at the speed of light - 300 million metres/second in a vacuum, slightly less than that in our atmosphere. How long it takes our neurons to process that information into anything our perception understands is a different matter.
2007-03-09 17:25:19 · answer #5 · answered by Megs 3 · 1⤊ 0⤋
Between the time photons impinge on the retina and the time the 'signal' travels the length of the optic nerve to begin processing is about 10 to 15 ms (.010 to .015 second)
HTH âº
Doug
2007-03-10 01:36:17 · answer #6 · answered by doug_donaghue 7 · 1⤊ 0⤋
The retinal cells need approximately 1/20sec to reset, dependant on intensity & colour. TV & film use this retinal speed to make the pictures appear smooth. (The brain scans the suroundings for movement, filling in stationary objects from memory)
2007-03-08 21:11:33 · answer #7 · answered by archolman 5 · 1⤊ 0⤋
I think this question is more related to time perception of sight. People can not register movement or light fluctuations that are faster than about 1/16th of a second up to 1/25 of a second in interval. This is why cheap TV animations look "choppy"; the frame rate is usually slower than 1/20, and you percieve the differences between one frame and the next. In higher quality video/film, at rates of 1/25 or faster, your eye can no longer percieve the images as individual pictures, and you percieve it as in motion.
This interval perception of the eye is also why hubcaps on moving cars often appear to be rotating backwards, when logically you know they are moving forward.
2007-03-07 21:40:31 · answer #8 · answered by perringer 1 · 4⤊ 2⤋
I believe it was approximately 1/10 of a second to process something. :/
2007-03-08 00:51:50 · answer #9 · answered by Bob R. 6 · 0⤊ 0⤋
Light speed
2007-03-11 09:59:45 · answer #10 · answered by jack_scar_action_hero 3 · 0⤊ 2⤋