Talk:Lilac chaser

History
Why is it called the Pacman illusion? The article doesn't mention it.
 * Because pacman eats those little dot-things. Maddie was here 04:29, 14 June 2007 (UTC)

Moving Image
But one real point is whether the content of WP should include a moving image--are there any others?--or do i misunderstand and the effect is produced from a static gif--in which case it should be pointed out in the article. DGG 09:02, 10 February 2007 (UTC)


 * Yes there are other moving images on Wikipidia. Particularly in the physics and astronomy sections.  The article does specify the affect is from the movement of the image.David Eagan 17:27, 14 June 2007 (UTC)

Beta or Phi?
Is the movement really beta and not phi?? --RawEgg 00:05, 14 June 2007 (UTC)
 * I have some trouble differentiating Beta movement from the Phi phenomenon after skimming their respective articles (at 3am local time). I notice however that the external link on both pages titled "Phi is not Beta" appears to be dead. The "classic" (i.e. only) example described in the Phi article is referring to two lines or images although on reflection I think this illusion can satisfy both criteria on one level or another.--Chris (talk) 01:59, 11 October 2009 (UTC)
 * The link works for me. The speed of this effect is somewhere between Phi and Beta examples in that presentation, so i cannot tell what it is (and I also did not get what is color of Phi phenomenon). (90.183.57.98 (talk) 21:00, 31 May 2010 (UTC))

at Phi_phenomenon it shows the Lilac chaser saying it's phi phenomenon and contrasts with other image showing beta, whereas the page here says it's beta

the illustration is actually borderline between the two phenomena. In beta movement you see one dot appear to jump to fill in the gap left by the preceding dot. In Phi phenomena, instead of seeing the dots move you see a phantom chaser dot which is the same size colour as the background. In the lilac chaser illusion you have the mixing up of two perceptual illusions, phi phenomenon and after image. An after image happens when you stare at a defined area of flat colour, say a red triangle and then look away. When this happens you see a ghost shape of the triangle in the complementary colour (in this example green). Now in the lilac chase illusion the after image interferes with the phi phenomenon, creating conditions whereby the dots actually erase themselves. (By the way, the confounding of the two illusion is why the lilac chase should not be merged with phi phenomenon in the Wikipedia pages) --Rodmunday (talk) 17:10, 2 July 2010 (UTC)

Inverted colors
There are three inverted colors on this Optical illusion.

Twentythreethousand 19:27 12 July 2007, who placed it on his


 * Instead of using eleven lilac out of twelve try using nine numbers from one to nine out
 * of ten number digits putting a space instead of ten and the result of the movement is a shadow (the
 * inverted color is shadow).

user:Twentythreethousand 21:50 05 October 2007

Not working properly?
Has someone vandalised the lilac chaser? It does not appear to be working properly on my computer whereas previously it has worked fine. —Preceding unsigned comment added by 82.44.4.243 (talk) 18:13, 16 August 2007 (UTC)

I can't seem to see it properly. When I stare at it, fairly soon I start seeing a light blue disk running along the lilac disks. But the lilac disks don't disappear regardless of how much I stare at it. J I P | Talk 10:39, 29 October 2006 (UTC)


 * They don't all disappear at once; it's only two or three at a time that do. Lycanthrope777 04:33, 28 December 2006 (UTC)


 * I can make them disappear all at once.  Stare very fixedly at the center. Redquark 00:58, 7 February 2007 (UTC)
 * Like many such visual effects, different people will see them differently. Some traditional demonstrations of optical illusions do work for me, some don't. (This doesnt). —Preceding unsigned comment added by David Eagan (talk) 17:27, 14 June 2007 (UTC)

Not disappearing!
In the image, the purple dots do not disappear: they are replaced by a larger dot of a colour similar to, but not with the exact same texture, as the background.

Does the illusion only work if this is the case?? If so, this needs to be mentionned in the text. —Preceding unsigned comment added by 142.157.192.76 (talk) 20:50, 7 March 2008 (UTC)


 * Illusion works as described for me. Try playing with settings on the interactive version at Michael Bach's web page of illusion --Chris (talk) 01:59, 11 October 2009 (UTC)
 * It's easy to get distracted by the apparent movement in the image and have your eye try to "track" the "green dot" (once it appears). Also, when intently fixating on a single point, your eye naturally makes small, quick movements called microsaccades which tend to ruin the illusion. I suspect one or a combination of both of these phenomena caused the effect described by the original IP commenter. I find if I "relax" and "zone out" a bit, the involuntary eye movements are lessened and the iilusion starts to work as advertised. - dcljr (talk) 22:16, 5 October 2017 (UTC)

Color Inversions
If the inversion of the lilac color is green, then shouldn't the inversion of blue be orange? I think that magenta color's opposite is green, and I know blue's opposite is orange. 69.14.217.129 (talk) 15:35, 4 April 2010 (UTC)
 * No, you are mixing the traditional RYB (or Goethe) color scheme, which is used in painting, with the RGB color scheme, which the eye uses. In it, the opposite of green is magenta, the opposite of blue is yellow (Yellow isn't actually a color the eye sees, the eye sees a mixture of red and green), and the opposite of red is cyan. -- megA (talk)

Why is the gap a lighter grey?
As described in the text, the gap in the GIF on the page is definitely a lighter bluish-gray, which is quite noticeable. It's not an illusion. You can open the GIF in an image viewer or editor and look at the single frames. Why is that so? I find it distracting and unnecessary. -- megA (talk) 18:44, 18 June 2010 (UTC)

I'm only counting 11 circles instead of 12, making me think someone manually edited out the twelfth at some point. My eyes are a little tired from staring at the screen too long, though, so if someone could double-check this that'd be good! -- Bryndel (talk) 02:15, 28 June 2013 (UTC)

a 4th illusion
if you move slightly away from your screen while still focusing on the center, you will see green dots all around the purple ones for a very short time. —Preceding unsigned comment added by 71.93.97.69 (talk) 04:47, 16 May 2011 (UTC)

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