Talk:Afterimage

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[edit] Flag Image

Any pictures besides the United States flag (with appropriate color substitution) to include in the main Afterimage page??

The inverse U.S. flag is a fairly classic example of the afterimage effect; I've seen it elsewhere. Why do you want to change it?

It is unbelievable the subversiveness of having to fix our eyes on the USA flag. Why not another country? If you saw it, it was probably in a US book. The image should be abstract and impartial. It is unacceptable. —Preceding unsigned comment added by 194.80.199.152 (talk) 18:08, 9 January 2008 (UTC)

You want another image, make another image. All you have to do is invert the colours! Leushenko (talk) 03:13, 4 February 2008 (UTC)

Actually upon thinking about it, a more neutral image would be great, but what would it be? The only thing that comes to mind is a selection of flags.... and then we could be upset about precedence instead...Leushenko (talk) 14:51, 6 April 2008 (UTC)
I once saw an afterimage effect that included movement. You stared at a spiral/whirlpool thing for thirty seconds, and then looked at a picture of clouds. The result was that the clouds then started to shimmer like water, due to the afterimage of the spiral overlaid on the clouds. It was a really interesting effect and would only require a simple animated gif. --ErgoSum88 (talk) 15:57, 6 April 2008 (UTC)

[edit] Not rods and cones

There is not universal agreement about wheither a negative afterimage results from adaption of cones; increasingly people are looking at adaption in ganglion cells in the retina and cells in the lateral geniculate nucleus of the brain.--Heida Maria 14:46, 22 November 2005 (UTC)

But I thought one can rule out LGN neurons' being primarily responsible for afterimages by showing that pressure blinding abolishes afterimages. That would be consistent with afterimages' being mediated by the photoreceptors or by the retinal ganglion cells. Robert P. O'Shea 07:06, 26 April 2007 (UTC)

[edit] YouTube links

This article is one of thousands on Wikipedia that have a link to YouTube in it. Based on the External links policy, most of these should probably be removed. I'm putting this message here, on this talk page, to request the regular editors take a look at the link and make sure it doesn't violate policy. In short: 1. 99% of the time YouTube should not be used as a source. 2. We must not link to material that violates someones copyright. If you are not sure if the link on this article should be removed, feel free to ask me on my talk page and I'll review it personally. Thanks. ---J.S (t|c) 07:29, 7 November 2006 (UTC)

[edit] This article needs to be improved

I'm sorry to be negative, but the level of explanation in this article is simplistic in some places and possibly incorrect in others. Dubious statements include:

  • "This is closely related to the phenomenon called the persistence of vision". If so then persistence of vision would have to involve positive afterimages but the explanation is for negative afterimages. For that matter, positive and negative afterimages are not distinguished.
  • "Normally the eye deals with this problem by rapidly moving the eye small amounts". This does not make sense linguisitically or logically. The eye does not move itself.
  • "the motion later being "filtered out" so it is not noticeable". Citation needed here.
  • "When the eyes are then diverted to a blank space, the tired photoreceptors send out little signal and those colors remain muted." This is very a very confusing sentence.
  • "The green color tires out the green photoreceptors". Although Hering thought there were green photoreceptors, no one thinks that nowadays. There are three cone types that respond to virtually all wavelengths of light but with peak sensitivities for short (S), middle (M), and long (L) wavelengths. A green light will stimulate the M cones the most, the L cones almost as much, and the S cones only a little. The ratios of these activities signal green. After adaptation, the ratios of activities of L, M, and S cones when exposed to white light are supposed to be the same as if the retina had been exposed to light of the complementary colour to the green light.

Perhaps Heida Maria can improve it. She seems to be better up on the literature than I am.Robert P. O'Shea 07:04, 26 April 2007 (UTC)