# What kind of optical illusion is this (pic in thread): **URL:** \ **Category:** Factual Questions\ **Created:** [March 2, 2012, 4:02pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555 "2012-03-02T16:02:24Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![cainxinth](https://avatars.discourse-cdn.com/v4/letter/c/7bcc69/32.png) [@cainxinth](https://boards.straightdope.com/u/cainxinth)\ **Post date:** [March 2, 2012, 4:02pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/1 "2012-03-02T16:02:24Z")
[pic](http://i.imgur.com/UjRML.jpg) Just curious if this effect has a name. ---
**Author:** ![Mahaloth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mahaloth/32/1079_2.png) [@Mahaloth](https://boards.straightdope.com/u/Mahaloth)\ **Post date:** [March 2, 2012, 4:04pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/2 "2012-03-02T16:04:29Z")
Is that an optical illusion or merely duplicating his mouth and eyes? [I’ve seen the Thatcher Effect, but am not sure if this is what has been done in your picture.](http://en.wikipedia.org/wiki/Thatcher_effect) ---
**Author:** ![Gyrate](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gyrate/32/3588_2.png) [@Gyrate](https://boards.straightdope.com/u/Gyrate)\ **Post date:** [March 2, 2012, 4:18pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/3 "2012-03-02T16:18:01Z")
> [@cainxinth](#): > > [pic](http://i.imgur.com/UjRML.jpg) AAAAAAAH!! Kill it! Kill it with fire!!! Oh wait…it’s just a picture of Steve Buscemi… AAAAAAAH!! Kill it! Kill it with fire!!! ---
**Author:** ![DCnDC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dcndc/32/2842_2.png) [@DCnDC](https://boards.straightdope.com/u/DCnDC)\ **Post date:** [March 2, 2012, 4:19pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/4 "2012-03-02T16:19:27Z")
I believe it’s called “Photoshop”. ---
**Author:** ![Keeve](https://avatars.discourse-cdn.com/v4/letter/k/f07891/32.png) [@Keeve](https://boards.straightdope.com/u/Keeve)\ **Post date:** [March 2, 2012, 4:25pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/5 "2012-03-02T16:25:54Z")
Ditto. I don’t see any illusion. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [March 2, 2012, 4:34pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/6 "2012-03-02T16:34:11Z")
> [@Keeve](#): > > Ditto. I don’t see any illusion. I don’t know about you, but for me, I find it extremely difficult to focus on the picture. My eyes keep fluttering back and forth between the two faces and it’s kind of making me feel like I’m drunk. My eyes or brain are trying to force the picture into single vision. ---
**Author:** ![cainxinth](https://avatars.discourse-cdn.com/v4/letter/c/7bcc69/32.png) [@cainxinth](https://boards.straightdope.com/u/cainxinth)\ **Post date:** [March 2, 2012, 4:37pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/7 "2012-03-02T16:37:14Z")
I thought maybe [future perception](http://en.wikipedia.org/wiki/Optical_illusion#Future_perception)? ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [March 2, 2012, 4:48pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/8 "2012-03-02T16:48:11Z")
It’s called [the double face illusion](http://www.perceptionweb.com/abstract.cgi?id=v100595), and the effect is indeed the difficulty in focusing on it. ---
**Author:** ![Enright3](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/enright3/32/2897_2.png) [@Enright3](https://boards.straightdope.com/u/Enright3)\ **Post date:** [March 2, 2012, 4:49pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/9 "2012-03-02T16:49:39Z")
> [@pulykamell](#): > > I don’t know about you, but for me, I find it extremely difficult to focus on the picture. My eyes keep fluttering back and forth between the two faces and it’s kind of making me feel like I’m drunk. My eyes or brain are trying to force the picture into single vision. That’s my take too. Something about the picture screws with my brain. ---
**Author:** ![Hail\_Ants](https://avatars.discourse-cdn.com/v4/letter/h/dc4da7/32.png) [@Hail\_Ants](https://boards.straightdope.com/u/Hail_Ants)\ **Post date:** [March 2, 2012, 5:00pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/10 "2012-03-02T17:00:51Z")
> [@pulykamell](#): > > I don’t know about you, but for me, I find it extremely difficult to focus on the picture. My eyes keep fluttering back and forth between the two faces and it’s kind of making me feel like I’m drunk. My eyes or brain are trying to force the picture into single vision. Me too. Its not an optical illusion per se, but it makes ma’ puzzler hurt looking at it! Human brains are hard-wired to recognize the human form, faces in particular, so anomalies like this make it hard to ‘render’ it, your mind keeps re-seeing it over & over. > [@Mahaloth](#): > > Is that an optical illusion or merely duplicating his mouth and eyes? I’ve seen the Thatcher Effect, but am not sure if this is what has been done in your picture. I never knew that was called the ‘Thatcher effect’. I remember when it was first discovered. I think I saw it in the now defunct science mag _ **Omni** _. I also saw it on Carson but he used a pic of Reagan (and others, maybe Thatcher). > [@cainxinth](#): > > I thought maybe [future perception?](http://en.wikipedia.org/wiki/Optical_illusion#Future_perception) That checkerboard & green cylinder illusion next to that paragraph totally blows my mind. When I first saw that a few years ago I was like, “What are they talking about? The two squares _ **are** _ different shades!” Liked it so much I made a T-shirt of it… ---
**Author:** ![standingwave](https://avatars.discourse-cdn.com/v4/letter/s/9de0a6/32.png) [@standingwave](https://boards.straightdope.com/u/standingwave)\ **Post date:** [March 2, 2012, 5:52pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/11 "2012-03-02T17:52:23Z")
> [@Hail\_Ants](#): > > That checkerboard & green cylinder illusion next to that paragraph totally blows my mind. When I first saw that a few years ago I was like, “What are they talking about? The two squares _ **are** _ different shades!” Liked it so much I made a T-shirt of it… I was actually playing with that one the other day trying to convince someone that they were the identical, even photoshopping the image by removing everything except the two squares. Then I was accused of cheating. :smack: The funny thing is, my artist BIL saw it almost immediately. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [March 2, 2012, 6:13pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/12 "2012-03-02T18:13:24Z")
> [@standingwave](#): > > I was actually playing with that one the other day trying to convince someone that they were the identical, even photoshopping the image by removing everything except the two squares. Then I was accused of cheating. :smack: The funny thing is, my artist BIL saw it almost immediately. That one isn’t that surprising to me–those shades look pretty similar to me, although I see that one is supposed to seen as lighter than the other, even though they’re the same exact color and shade. It’s [this one](http://blogs.discovermagazine.com/badastronomy/2009/06/24/the-blue-and-the-green/) that always gets me. The “blue” and “green” spirals are actually the same color. ---
**Author:** ![jackdavinci](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackdavinci/32/3259_2.png) [@jackdavinci](https://boards.straightdope.com/u/jackdavinci)\ **Post date:** [March 2, 2012, 6:28pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/13 "2012-03-02T18:28:56Z")
> [@pulykamell](#): > > “blue” and “green” spirals are actually the same color. I’m very disappointed in whoever created this. It might indeed work as described, but the actual graphic used is not an accurate rendering of the description. Whatever graphics program they are using has caused the one green spiral to be bordered by blue pixels. So it’s not surprising it looks blue. It is partially blue! I’d like to see if the effect works as well when rendered properly. ---
**Author:** ![tdn](https://avatars.discourse-cdn.com/v4/letter/t/94ad74/32.png) [@tdn](https://boards.straightdope.com/u/tdn)\ **Post date:** [March 2, 2012, 6:45pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/14 "2012-03-02T18:45:24Z")
> [@Keeve](#): > > Ditto. I don’t see any illusion. It looks like he has two mouths and four eyes. But in reality he has four mouths and eight eyes. That’s the illusion! ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [March 2, 2012, 6:58pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/15 "2012-03-02T18:58:22Z")
> [@jackdavinci](#): > > I’m very disappointed in whoever created this. It might indeed work as described, but the actual graphic used is not an accurate rendering of the description. Whatever graphics program they are using has caused the one green spiral to be bordered by blue pixels. So it’s not surprising it looks blue. It is partially blue! I’d like to see if the effect works as well when rendered properly. Well, the amount of color feathering there is enough to be negligible, in my opinion. It looks to me like it was an issue in downsizing the graphic (if you don’t use “Nearest Neighbor” interpolation you get color blending) or possibly the compression (I didn’t check what file format that image was in.) Anyhow, the graphic below that one shows the effect pretty clearly, too, but here’s my chopped up version (sorry, I didn’t have time to create spirals). [See here.](http://www.pawinskiphotography.com/public/illusion2.png) ---
**Author:** ![yearofglad](https://avatars.discourse-cdn.com/v4/letter/y/b782af/32.png) [@yearofglad](https://boards.straightdope.com/u/yearofglad)\ **Post date:** [March 2, 2012, 6:59pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/16 "2012-03-02T18:59:01Z")
> [@jackdavinci](#): > > I’m very disappointed in whoever created this. It might indeed work as described, but the actual graphic used is not an accurate rendering of the description. Whatever graphics program they are using has caused the one green spiral to be bordered by blue pixels. So it’s not surprising it looks blue. It is partially blue! I’d like to see if the effect works as well when rendered properly. It’s “rendered” just fine. There is no border of blue pixels; that’s your eyes playing tricks on you again. Zoom in to, say, 3200%. You’ll note that the blue “border” remains the same size despite all that zooming it; it’s because the border is created by your eye, not by whoever created the image. No need to be “very disappointed.” You can now be “very impressed” or “suitably entertained.” ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [March 2, 2012, 7:43pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/17 "2012-03-02T19:43:43Z")
> [@yearofglad](#): > > It’s “rendered” just fine. There is no border of blue pixels; that’s your eyes playing tricks on you again. Zoom in to, say, 3200%. You’ll note that the blue “border” remains the same size despite all that zooming it; it’s because the border is created by your eye, not by whoever created the image. There is a small amount of anti-aliasing if you look at the first graphic at 100% in Photoshop. Like I said, it’s a negligible amount that doesn’t contribute at all to the illusion, so far as I could see, but you can click on my graphic for a completely true 3-color image. ---
**Author:** ![RadicalPi](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/radicalpi/32/9806_2.png) [@RadicalPi](https://boards.straightdope.com/u/RadicalPi)\ **Post date:** [March 2, 2012, 7:52pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/18 "2012-03-02T19:52:58Z")
> [@pulykamell](#): > > There is a small amount of anti-aliasing if you look at the first graphic at 100% in Photoshop. Like I said, it’s a negligible amount that doesn’t contribute at all to the illusion, so far as I could see, but you can click on my graphic for a completely true 3-color image. The anti-aliasing might be resulting from Photoshop. I opened the image in Paint, and there doesn’t appear to be any anti-aliasing at all. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [March 2, 2012, 8:04pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/19 "2012-03-02T20:04:13Z")
> [@RadicalPi](#): > > The anti-aliasing might be resulting from Photoshop. I opened the image in Paint, and there doesn’t appear to be any anti-aliasing at all. :smack: You are indeed correct. I should have realized that. Opening it up in Preview and inspecting the first file on that page indicates that it is, indeed, comprised of exactly three colors with hard edges. I am a double idiot. It does open up fine in Photoshop, showing only three colors. I must have accidentally resized it or something, because otherwise I can’t explain how I got aliasing when I first looked at it. ---
**Author:** ![Bytegeist](https://avatars.discourse-cdn.com/v4/letter/b/9dc877/32.png) [@Bytegeist](https://boards.straightdope.com/u/Bytegeist)\ **Post date:** [March 2, 2012, 8:07pm UTC](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555/20 "2012-03-02T20:07:31Z")
> [@Gyrate](#): > > Oh wait…it’s just a picture of Steve Buscemi… He’s kind of funny-lookin’. More’n most people. [Next page](https://boards.straightdope.com/t/what-kind-of-optical-illusion-is-this-pic-in-thread/614555.md?page=2)