By on May 5, 2006, with 79 Comments

How come these two chinese girls have so small heads? Are they shrinked in some vodoo way? Probably not, but if you solve this, please comment and share your thoughts with me. I have no clue! This optical illusion picture was taken by Shoji Uchida, a very talented and interesting photographer whose pictures are showcased here.

• Angela

It is the defraction of light that makes their heads appear smaller. Look at a straw in a glass of water. Notice how the straw appears to be a different size under water than the straw above water.

• Dave Goodman

What Angela said. :)

The refractive index of water is much different from the refractive index of water. A lens is created by light passing through materials with a different refractive index, and the water against the camera magnifies more than air against the camera.

• roundglass

Straw in a glass of water… Is the glass round? Then it is acting as a lens and the girls must be in a round tank also. Do fish look bigger in a rectangular fish tank?

• Uli Romahn

Well, the above is only partially true ;)

So, the actual projection of a real picture onto a two-dimensional pane of a film (or a digital sensor like a CCD) is done through one or many lenses. Actually, the lenses of a camera are a combination of multiple lenses with even different material per lens to get certain attributes.

To keep this story short, each lens is engineered to project the “real world” onto two dimensions with a certain scale. Now, this gets actually accomplished by passing light rays emmitting from the original object (e.g. sun light that gets reflected from that object) through the lense onto the projection pane. When the light travels through the lens, it gets “diffracted”, i.e. “bend” in a certain way. The amount of “bending” or “refraction index” is determined by the material. However, this refraction index is not an absolute value but always relative to something.

For example, the average refraction index of light in glass is 1.5, but always relative to air at “standard conditions” (to explain that would really take too long ;).

And herein lies the solution to this picture: when the lense is submerged in water, the refraction index of its glass is not relative to air anymore, but relative to water. The refraction index of water (relative to air) is 1.33. When light travels through water into the lense, the resulting relative refraction index is actually 1.5/1.33 = 1.13. This is a much smaller value, which means the lens is much “weaker”. In this case, the lense was probably slightly “magnifying” and since submerging it into water made it weaker, the magnification was less – et voila, here you have your smaller heads.

Guess, that was still a bit long, but Physics is just not easy.

• Guanti

it doesn’t matter about shape. Try it in a bath with your fingers at different angles half in the water, its cool.

• me

… but did you all keep in mind, that the photographer’s outside the tank!?!?

• Tony Carbajal

Any scuba diver knows that the mask magnifies underwater images beacause of the different light defraction index of water and the air inside the mask. Thats why we love to dive naked :-)

Those who live in San Diego can verify this effect in the dolphins pool on Sea World. The distance seems to be greater above the surface than in the side window.

• Hai

i think somehow the water magnifies the rest of their bodies so their heads look small

• Chaos

nice one…… well, that is the same trick when a pencil is put to a glass of water……
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• biclops

two words, genetic engineering

• John

Dave Goodman on 9:02 PM
What Angela said. :)

The refractive index of water is much different from the refractive index of water. A lens is created by light passing through materials with a different refractive index, and the water against the camera magnifies more than air against the camera.

How is water different?

The refractive index of water is much different from the refractive index of water.

• The Spud

Um, it’s so obvious that their heads aren’t small, it’s just that their bodies are huge!

• Amy

they just have small brains that’s why they’re heads are that small.. hihih..

• Kat Bell

Angela is right! this trick is made simply by the effects of light on water, when you put your hand in the sink you will notice that your hand is wider that it is out of water.

A simple trick but very effective!

• neitocus

there HOT

• M 2 the H O

things look bigger underwater,put your fingers in a glass of water, they are bigger in the water than out of it, freaky!

• Terri

is that why my ex husband always wanted to sit in the jacuzzi?

• momo

PHOTOSHOP!!!!!!!!!!!!*^_^*

• sum guy

lol they look wierd

• jean-ius

thank you eveyone for stating the obvious.

• RandomGuy

tho the ‘magnifies thro refraction’ theory is valid when they are actually i the water but it is clearly photoshopped. im suprised no one else noticed this but their bodies are shiny and their white shirts arent very, well to be blunt, see through so its clerar that their bodies wernt underwater at time of photo and the the water/air border provides a nice space to merge the 2 photos (two bodies to two heads) together. another mystery solved…

• Matt

Water bends light, period, just like glass or any other transparent material. It’s hard to notice, because windows are so flat and smooth, but the images you see our your living room windows are distorted as well, just not much.

• Pandas

no clue. :)

• anonymous

I think it is because the photo was shot from under the water, looking up, so the head and body sizes are different

• Mrs Dumbness

Firstly i would like to say to he/she Uli Rohman that we dont need to know that much of your stupid science knowledge, secondly it aint really that hard, obvioulsy when you put somthing in water it appears larger DUHHHHHH. finally to dave goodman (your name gives it all mr goody too shoes) we dont need a science lecture.

WATER MAKES OBJECTS APPEAR LARGER THAN THEY ARE….. WOOOHOOO IM CLEVER IM MRS ROHMAN GOODMAN.

• Mrs. Pitt

That is really wierd. I think that they took two pics and ethier used image blender or Adobe 6.0 Photo. And by the way vodoo or whatever you call it does not exit even though you may think that it is cool and that is does exist you are going to have to face the facts some day. Well I thought that i would just let all you pepps know what I think so now you know. Have a good.:)

• thomas .h

if u take a clear galss of water then a straw put it in the water look at it about the hight of the water then notice the straw is somahow bigger in tha water it warks the sam way ur eyes suck lol jk

• Anonymous

weird

• Anonymous

its pretty obvious…when you put something halfway in water, the top half appears smaller than the bottom half

• Anonymous

Those girls are obviously Japanese. Don’t just asume because they are oriental that they are automatically Chinese. There is a huge difference.

• Anonymous

I’m ‘oriental’ and I can’t tell the difference between Japanese and Chinese people.

• Anonymous

I’m sorry but all of you are wrong (well you are right when it comes to expaining how water works and the index and other stuff) but the photo wasn’t made that way. There were 2 pictures taken: one of the water and the second one of the girls. THE GIRLS ARE NOT IN THE WATER. They just seem to be in it. Now in photoshop you duplicate their heads onto an other layer, erase their original heads and resize the copied ones. Now on top of those two you add the water (with thish you can play a bit and make it more transparent leaving the line visible). On the rest of the body u use a gradient (from black to transparency) and add a backgroud above the water level (u can even draw it by hand).
The Picture is so great because the photographer used the rules of nautre for his cause but because everybody who looks at it think he did :)

sorry for spelling mistakes (english isn’t my native language)

• Anonymous

This am be an photojiggered picture, albeit based upon a photo that illustrates a real phenomenon (refraction of light by water).

The manipulation performed was to move the heads, but leave the size unchanged. Unmolested, the photo would have the models’ heads closer together, and apparently disconnected from their necks.

The explanation is due to the angles between the focal point (i.e. the observer’s eye) and the models. Just as the light from the bodies is refracted (it appears larger), so is the space between the models.

The contrived illusion takes advantage of the casual observer’s experience of refraction (the pencil in the water bending), and the fact that they will not think about empty space being refracted.

• Candy

Weeeeelllll…..

I think it’s pretty obvious……

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• its almost 4/20/07 !!!!

well i think it may be just a painting that the girls are standing behind. and its an advertisment for nike i mean look at the logo on their swimsuits.. !]

• qwertyuiopasdfghjklzxcvbnm’s wife

my husband got me hooked on this website! It looks really cool!

• qwertyuiopasdfghjklzxcvbnm

where are they swimmin’ it looks so dark?

• Anonymous

Shoji Uchida is a Japanese name… any chance these are Japanese girls, not Chinese?

• Anonymous

there are tow diffrent pics

• Anonymous

All u smart ppl rule the world!

• phillip

there are two diffrent pics

• Anonymous

Photo shop of two pictures:-D.

If they were really underwater, we would be able to see their boobs; they’re wearing white sports attire. I mean come onnn, they don’t even look wet. and the shadows on the bottom corners, they spell out photo shop.

• Anonymous

I think its one of those boards you stick your head in to get a photo lol, notice how you cant see the right chicks hair in the water

• Ana-maria

welll maby he took the two girs from the water and then just cut off the heads in the pichure editing and then took another pichure when they r out of the water and cut the body of that pichure and then just connected them toghether

• Yoda82

The water magnifies the body, the head it actual size

• http://www.moillusions.com Loudogg

I Will stick with your solution.

• the David

Yoda82 is one of the few who have it right here. Don’t you does remember elementary school science. What light passes through water gets distorted. That’s why you can use a drop of water as a magnifying glass

Water distorts things, making them seem bigger. Taken from a unique angle,it makes them look like they have small heads. And I think they’re Japanese, not Chinese.

• Sarah

In Chinese culture it is very attractive to have a small head

• krista

if u ever look under watter everything would be a bigger size so when they took it they put the cam a bit under the water so when they did

light in water acts differntly to light in air. It bounces off every particle in the water and distorts the image of the two girls, making the imagine below the water larger. Water kinda acts like a magnifier.
I’m a high school grade C student and even i know that!!! Also if you look at the surface of water from below it it acts like a silver mirror and you cant see above it, unlike if you look down on the surface you can see the bottom!

• bella

what happens is the light is bent as in refracted so there bodys appear bigger but they are not as big as they apear btw this is from a 5th grader!

• O_o

Holy mother of magnification.

the reverse of clear air makes objects looking nearer as they are.

water magnifies. (look into an pool which isn’t too deep an you see what i mean.

an a photo which depicts both elements (in water and out of water) looks of course strange to the normal eye.

it might be shopped (2 pics one over the water one under) to increase the “alienation” but i think it’s a play of angle and distance.

• mysteryman

its probably just from one half under the water and one on top

• http://www.wtf.com idc

• منتديات

very good
and picshr ver good

• دردشة

very goooooood

• دردشة

This am be an photojiggered picture, albeit based upon a photo that illustrates a real phenomenon (refraction of light by water

• ERgs

it’s because the water magnifies the bodies. hope you had a waterproof camera!

• ali

its the water, it dis-ordinates(yeah i know thats spelled wrong) the body

• PM

Cool pic. The illusion is that we think the girls are under water. Their bodies are well oiled, but their clothes are dry.

• http://www.pbase.com/dantom/aqua Daniel

Well easy! Water magnify, so when you have picture partly in the water, it makes that illusion!

• photographer

There is such thing as a split-lens camera where you can, as in this photo, zoom in underwater and stay zoomed out above water. NatGeo marine photographer David Doubilet uses this quite a bit.

• Rasengan

Just put your finger in a glass of water and you’ll get the answer :P

• moris

this is crap, are you trying to make my lady gaga?

• gujjar

well i believe that the models are standing behind a screen that has two headless underwater bodies i.e the bodies and heads do not belong to same person

• Anonymous

the bodies are underwater, making them look bigger Einstein

• madam curie(in making though) :)

Its just the effect of REFRACTION OF LIGHT!!!!

• aunglay

good sex>>> :P

• http://kittentumour.blogspot.com/ Jon

Light is refracted (bent) more in water than in air. So if you are under water, things appear a third larger and a quarter nearer. So the girls’ bodies appear bigger than their heads.

• http://moillusions.com hunter

its because when when the object refracts through water the object is magnified. one example of this is if you were to put a straw in a glass the straw would look bigger in the water.

• Saeed Yaqoob

who said that the bodies belong to the same girls who’s heads are in the pic?!!! infact the lower part of the pic “the bodies in the water” is just a drawing.. and the heads only r the reall.. and the 2 pics “heads and bodies” been photoshopped as if the girls bodies r under water!!

• Anonymous

Look up Snell’s Law.

• Maya

I know! so water makes things look WAY bigger. experiment- put half a pencil in a glass of water. What does it look like?

• ron(rustic)

i think its the way it was taken the lense of the camerA THE ILLUSION BEcause it was shot at the top veiw…..i think..

• Alysha

things look bigger under water

• angelina

refraction of light dude……try elementary school again. =)

• I say

The light and vision that reflects in the water makes the picture in the water bigger than the picture above it. Fysiks only. ^^

• http://myaple.blogspot.com/ lost in translation

very fun