Relative Coffee Cups

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Concerning the illusions, I found this one through Google image search. I really liked it. Now, if I started talking too much about it, the answer would become more than obvious. I wouldn’t like to ruin this one for you, so I’ll let you solve this by yourselves. All I can say is that it has something to do with Relative Sizes. Shouldn’t be too complicated, though.

Are these cups different in size?
Are these cups different in size?

113 Replies to “Relative Coffee Cups”

  1. the cube is a drawing on the paper and
    the 2 cups are just seperated from each other
    or spreat apart from each other
    both cups are the xact same

  2. Answer : Yes. Using my simple method of measuring the small one with my fingers and comparing that to the larger one, I can say (Without a doubt) that they are different sizes.

  3. They are both the same size in real life, one is just further away, making it look smaller. It’s not an illusion in the slightest, it’s just perception.

  4. No, they’re the same size. The “smaller” one is placed farther back and on top of the drawing of a cube (which, like the illusional chalk drawings, appears to be 3D when you stand at a certain angle).

  5. Yeah, they look different sizes, but the cube on the table looks like that 3D Drawings, and the “small” cup is just near to the edge of the table.
    sorry if my english is bad, i’m brazilian!

  6. No they aren’t the same, but I would compare them the same way I would two triangles with the same angles and different side lengths. They are similar coffee cups.

  7. Calvin is right, they are the exact same size. The cube is a drawing and the cup that looks smaller is farther away.

  8. in real world both cups are the same size, only 1 is in the foreground and 1 in the background

    in the picture the right cup is obviously bigger

  9. Going by pure measurements in 2D, no, they are of different sizes.
    Going by relative measurements of the cube, no, they are different sizes. One is approximately 1 1/2 block size, and the other 2 1/2 size.

    BUT… going by the wrongly shadowed cube, I would say that the cube is a drawing, and the cups are of the same size.

  10. In reality they are the same size. The “small one” is further that the “big one” and on a drawing as calvin suggested. This way the “small” looks small and on a cube, where it is the same size but further..
    …or something like that! :)

  11. Yes, the “dud” edges and lines of the cube are a giveaway. Also compare the directions (and number) of the shadows of the cups and box.

    So answer is, they certainly could be the same size. Or the far one could even be larger.

  12. The cube is obviusly a picture. The cups are same size, but one is nearer than the other. One detail: The light is over the cups, but the cube shadow is on its left ;-)

  13. In this picture the cups SEEM to have different sizes. But if you look close, you can see that the cube not real is but drawn.And so you can figure that the cups are the same size-in reality, that is…

  14. On the picture they’re not, but it is an real picture, so no photoshop or anything. The cube, and it’s shadow are drawn on the surface on which both cups are standing. The left one, a bit further away from the camera and in such a position that it seems as if it was on top of the cube.

  15. *spoiler*
    see that brown sheet of parer that everything is sitting on?
    the cube thingy is just drawn on it.
    then the “smaller” cup was set farther away on the paper, giving the allusion that it is set ontop of the cube.
    but the two cups are the same size, just the “smaller” one was set farther away :)

  16. illusion** sorry :P
    and u can tell that it is drawn, because the angle of the shadow of the cube, doesnt match the angle of the shadow on the cups :P

  17. Oh I see – the cups appear to be next to each other but at different heights and different sizes. But they are really the same size and one is farther away than the other.

  18. In real life they are the same size. One is further away than the other. This is hardly an illusion. In the picture they appear different sizes. This happens as the light is almost “collected” in to a point in our eyes. The further away something is the less light comes from it and the more light comes from its surroundings. Wikipedia says “If two objects are known to be the same size (e.g., two trees) but their absolute size is unknown, relative size cues can provide information about the relative depth of the two objects. If one subtends a larger visual angle on the retina than the other, the object which subtends the larger visual angle appears closer.”

  19. The cups are both in line with the corner of the cube so they are both the same distance from the viewer. The handle is not visible on the left cup but it is visible on the right cup. The diameter of the left saucer measures 1-1/2 inches and the right saucer measures 3-1/2 inches on my monitor. So I conclude the cups are different sizes, the right one being larger.

  20. Perhaps in real life they are the same size. On the screen, they are clearly different sizes. Doesn’t really seem like much of an illusion, at least without more explanation or another picture from a different angle.

  21. Its not to do with the size of the cups and saucers, it their relative position. The white cube is drawn on the brown piece of paper. Both cups and saucers are on the same level, with one being further away and therefore smaller. They are placed on the picture to give the illusion that one is ‘higher’ than the other – whereas they are on the same flat surface.

  22. They are the same size as they are both real cups and the rest ist a plain surface, both cups are placed on.

    or …….

    Only the cup in front is real while the rest is plain ???

  23. More explanation is needed tbh:P what exactly are you asking, do they LOOK the same? Are they the same? well no they’re not the same size… unless of course you mean IN THAT 3D WORLD,, then yes they are because i think the cube is fake,,,, and just a drawing or something… so yeah… but the closest cup to us is definitely bigger in size in the 2d image

  24. The brown piece of paper on the wood floor has a cube drawn onto it. one cup is close to the camera and the other (of equal size) is set far from the camera on top of the picture of the cube giving the illusion that the cup is actually on top of an actual cube. The mugs are indeed the same size.

  25. I think calvin is correct. The cube is a drawing, and the second cup is in the background, which is why it appears smaller. In life, the cups are the same size, but in the photo they appear different. This is an example of the technique known as forced perspective. It was used in some scenes in the Lord of the Rings movies to make the Hobbits look smaller than the other chracters without having to digitally alter things.

  26. I think I was trying to over complicate it. It was so obvious to me that the other cup was further away, and not raised on the “cube”, and that the cube was just a drawing – that I just spent about 20 minutes trying to figure out what the optical illusion was. Lol.

  27. To me it looks like two cups the same size at either set apart on a table with a cube painted on it; the cube looks like a drawing, not a real cube, because the way the shadows fall doesn’t match the cups’ shadows at all.

  28. Ooh, that’s very cool. I believe the cube is painted on the table (it’s not 3D). The smaller-looking cup is farther away on the table, but it appears close because it is on top of the cube. I say this, but it still seems like they’re different sizes when you look at them.

  29. This is a photo of two identical cups sitting on a piece of paper that has a 3D cube painted onto it. I don’t believe that it has been photo-shopped at all.

    The illusion is that our brains tell us that the right hand cup is a giant cup, and the left hand cup is a tiny cup. In other words, our brains tell us that if the cups were pictured side by side, the one on the right would be larger than the one on the left. But in fact they would be exactly the same size.

    Which I think is just another way of wording what Calvin said.

    Clearly it’s not an illusion like those ones of the identical cars along a road that look like they are getting larger as they go back.

    It’s more in the style of the 3D pavement chalk drawings.

    What I would love to see is the same image photographed from a different angle, say, from the side. I think that would highlight the exact nature of the illusion.

    Who knows, perhaps I will rig up my own version of this and post a few photos! ;-)

  30. Ok, I just opened the image in Paint and I concluded that the cups are different sizes! Of course, the finbgers measurement might also do the trick… and it is easier. Duh for me.

    By the way, I just used the Facebook button!!

    Yeah!!! Love your site! I visit it daily!!! Thanks iGoogle and Mighty Optical Illusions!!

  31. Go Tim ;D!
    I feel sorry for the people who don’t understand the “cube” is just a drawing.

    Another way to tell is the shadow on the cube is extremely long while the shadow on the cup and saucer to the right show that the lighting must be from above.
    The two shadows do not match.

  32. OMG! People who think that the cups are different and used their fingers or Paint or something else to measure them on the screen are just so stupid. I’m sorry for being harsh, but have you actually used your brain before writing that. I swear, you should be cited in the Stupidity Encyclopedia. This is the matter of perspective which gives us an optical illusion. It doesn’t matter if the cups are different on the screen, what matters is the way they are in REALITY and in reality they a re exactly the same. Read ‘calvin’ for details!

  33. “calvin” – You’re spot on.
    “KReatz” – Kudis for pointing out the false shadow that further verifies calvin.
    “Why” – You’re a moron, and have the arrogance to back it up.

  34. seeing as we can only tell if the two are the same size from a 2d picture. they are not the same size. you can’t tell depth and perception in 2d form. so comparing the two cups they ARE NOT the same size. we can assume that they are by knowing the cube is really a piece of paper and the smaller cup is father away but we can’t know if they are the same size or not.

  35. I’m going to second what first-poster Calvin has said. I didn’t notice it at first, but that box really it just a flat object and the cups are separated by horizontal, not vertical, distance.

  36. in reference to each other and/or to their surroundings they are the same size.

    in the picture each cup has the same measurements by counting cublets on the cube.

    in the 2D of drawings however they are indeed different sizes.

  37. even if this is 3D the two cups are different in size. the small one is NOT further back it is ELEVATED. if you look at the relationship of the two cups locations against the cube you find they are both the same distance from the camera.

    2D or 3D one cup is small the other large.

  38. It’s just a matter of perspective.
    The 2 cups are on a table and a drwaing of a 3D cube is also made on this table.
    Check out this drawing:

    Not very accurate (with MS Paint :-) ), but you can see that the perspective of the table goes to 1 point (blue lines). From this point you have to draw 2 lines (red) to the outer size of the cups. And if you compare the width between these lines at a certain point (the green lines), you can see that they’re actually of the same length.
    This proves both cups are in fact of the same size.

    Hope people understand what I’m trying to explain, my english is not that great :-)
    But it really proves they’re the same size. This is the only way you can tell for sure!!

  39. ok
    1) very cool
    2) the cups are the same size
    3) the cube is a drawing making it seem 3D
    4) the ‘smaller’ cup is just put at the end of the drawing, as if it was on the ‘cube’

  40. I agree with Calvin, the cube is a drawing on a piece of paper which is on the floor. The two cups are several feet apart and the same size.

  41. Vurdlak, reading some comments and suggestions on previous days (previous illusions) I now definitely agree that you do need to hire a writer.

    Now nothing personal here. I like you, I like this website and I like this particular illusion. But you didn’t present it right with your words. Hence some people (looking at comments in THIS post/illusion) didn’t get it. Or got it but didn’t even think it’s an illusion, just simple perception.

    Some people do get it that the key of the illusion is actually the 3D drawing of the cube. It’s not a real cube, but a 3D drawing of a cube to make the (seemingly) smaller cup appear to be on top of it, when the cup is actually the same size and on the same level of height (not higher) with the “big” cup, only placed farther away so it seems smaller.

    It’s a good illusion, but it would’ve gotten better response it deserved if you’d give it a better foreword.

    Just my two cents, pal. Hope you appreciate it.

  42. The illusion is that this is a real photo (unedited), of two cups, both the same size in real life, one of which is meant to look smaller and on top of a three dimensional cube, when in reality both are on a flat surface.

  43. It kinda reminds me of the guy that draws the chalk perspective images in the streets. Cups are the same size

    also checking to see how the Facebook image thing works… and yes, I can see my picture

  44. Both the same size as the cube is a drawing that looks 3-d and the left cup is further back therefore it looks a smaller.

    You are cool if you agree ^_^
    if you dont (like Tim collins) then…… o_O

  45. First, this shouldn’t qualify as an “illusion” as the perspective does exactly what we it should when translating 3D to 2D.

    Second, the shadowing of the cube is all wrong compared to the cups. It introduces a third light source that isn’t represented in the rest of the picture.

    This one is pretty lame.

  46. I think I’ve got it:

    The closest cup is from an Ancient Polynesian archeological dig site, and the furthest one was bought at a local thrift store, for about 50 cents.
    Since they are identical we can only be left to assume that the Ancient Polynesian culture was indubitably far more wide spread than modern anthropologists initially concluded.

    As for the 2 dimensional Rubik’s cube, it makes a pretty nice table by the looks of it.

    P.S. for those of you who don’t realize, I am completely joking, as this illusion has already been solved. ;-)

  47. same size.

    the cube is a drawing on the brown paper.

    angle of the shadow drawn on the paper dos not match the shadow on two cups.

    the ‘smaller’ cup is simply further away from the camera.

  48. We can not know. None of us.
    Apart from a confusing drawing of a cube with a shadow in the wrong direction we have got no means to presume a relation here.
    So I am surprised how many ppl apart from the jesters are able to give a smart and definite NO or YES while we have such an excusable reason to capitulate :-)

  49. Both are the same sizes, the thing is that are using a visual effect tring to make you think the are in the same position, but they arent, they are far, and the cube fisically doesnt exist there, it is a paper draw.

    How to know, look at the shadows!!

  50. I’d imagine the cups are the same size, but because the one on the left is further away… but still, i can kind of see the cube drawn on the paper… but now my head hurts so thanks…

  51. This is a photo. Look at the table and cups and the light reflections and the shadows. The cubes are a drawing. It is unlikely this photographer would have two identically painted, yet different sized cups and saucers to take a picture of. Therefore, the cups are the same size as each other.

  52. its an illusion and illusions answers dont arent based on mesurements. and for those of you that think they are different sizes illusions are supposed to trick your mind into thinking what you see is the real size or an impossible thing.

  53. They are different. There are two illusions. The one with the cube. The second with the cup placement. For the opening of the closer cup to be the size and angle it is, the table would have to be bent. You would not be able to lay a ruler flat across the top of the two cups.

  54. Shame there isn’t a second photo in the gallery, perhaps the view from directly above would reveal all. The “one-eye” of a camera can be fooled with such a contrived set up.

    The cube should be in carpet tiles at the main entrance, just inside the lobby.

  55. Yes they are the same size in RL.
    Yes the smaller one is placed further away in RL

    This has nothing to do with the intended illusion though.

    The illusion is that that cube make it appear to be at the same distance from the viewer, while in fact it is not

  56. I don’t think the illusion is supposed to be “are the two cups the same size?” I think it’s supposed to be “are to two cups the same distance away from the camera?” and the answer is yes. The cube that the smaller cup is sitting on is right next to the larger cup, but the smaller cup looks like it is farther away, but can’t be.

  57. The cups are visually different sizes, but we are led to believe that they are the same size “in real life” (although this is absolutely inverifiable).

    Good illusion, though this could be done much better.

  58. Being given the context (the site we are on), I wonder (without a hint) if the “large” cup isn’t in fact SMALLER then the “small” one…

  59. One of the keys to making this coffee cup illusion work is knowledgeable use of the camera. The photographer needed to use a very small aperture to get a big depth of field in order to not give away the distance of the coffee cups from the camera by way of focus or lack thereof. Viewers have learned to judge placement in a 2D image by focus, so removing that information is critical. They could have done a better job of faking the cube shadow, but otherwise pretty good.

  60. cody

    perception IS reality.

    The cups are different sizes IN the 2d picture. That is the perception, which makes it reality.

    The cups are the Same size if you were to see them in person, hold them, etc…..that is a different reality than what is shown in the 2d pic.

  61. fried man,

    perception is recognition and interpretation, the way our brain perceives things but it is never THE reality. That’s why it is an optical illusion, when our brain is tricked to see what isn’t really there.

    And here, it’s not the question if these cups are different in 2D. If it were the case, it would be too obvious and pointless to do this optical illusion.

  62. dear vurdlak, i feel so sorry for you… i enjoy coming to your site whenever i see something nice on my igoogle gadget and each time, out of curiosity, i read the comments people post… i’m sorry guys, but some of you are a real pain… who cares how vurdlak writes the article? this site is about illusions/mind tricks, not bbc latest news. also, why does everyone attack everyone else when they have different opinions? it’s all relative – of course the two cups are the same size (or so we can assume otherwise what would be the point of this illusion?) but it is true that if you’re talking about the picture, not the actual table with the two cups, they’re different sizes. ok, i personally think that’s a lame remark that doesn’t need to be pointed out, but still it’s true so just let people think what they want if it makes them happy… having said that, i do need to say that i love david redman’s comment… LOL!

  63. I must admit that this one stumped me for awhile until I read a comment that told the answer…I was very much dissappointed in myself for not figuring it out but of course stumping me get’s a five star rating on my side….

  64. it is not elevated how do i know look at the floor wood flooring then carpet then more wood flooring so the cups are on a carpet with a cube on it, how it works is your eyes are lieing to you, because of the 2d image with the 3d cups in a 2d picture so all of the 3d is 2d to u cant tell what is what

  65. Hey I believe that whole brown square the 2 cups are sitting on is a drawing. That would explain the inconsistancies of the shadows. They’re the same size, just a few feet apart.

  66. I have to say that the 2 cups are exactly the same, the rest of the picture is just a drawing to make our eye’s see that the one is bigger than that of the other, but than again, they really could be totally different sizes but I am still going for my first option of them being the same.

  67. OMG. It isn’t that hard! The cube is a part of the carpet, duh!
    If anybody knows how shadows work, you’d cleary see that the cube has a shadow thats going the wrong way. If the carpet was just 1 color it would be obvious to everyone. I think that the cup in the background is actually bigger. Just copy in paint, and cover the whole cube and it’s shadow until its not visible anymore. A whole other world will open for you dumb people. No offence to the ones that had it figured out, but I didn’t wanna frustrate myself so I didn’t read all the comments.

  68. What I’d like to know is how to draw geometrically these eyes-fooling perspectives (trompe-l-oeils).-Maybe something like the mypicx link given by Paul.
    Obviously one could project the picture of a cube on the table, at the same place one is going to take the picture, then draw.
    And, yes, the reel issue here is that there is no coffee in either of them!

  69. no they arent. they are the same size because the cube is painted on the table thingamajig & theres a copy of the cup on top.

  70. theyre not the same size… as 1. it is a picture. it has only one size (ownage 1 fkyeah).
    2. as i try to size the big cups with my fingertips, ga back to the other cup with the same size….not the same…

    Sorry u all got owned by ME

    1. i’m sorry but this is an optical illution, they are not the same size they are different sides of something, has it never occured to you things look smalled when they are further away, so no, we did not all get owned by YOU!

  71. the cups are the same size it is jst that one is on the other end of the coffee table and the cube that is on there gives it the illusion that it is smaller

  72. No way to tell. Its obvious the picture is setup to make one look bigger then the other. But with only the picture to go by, theres no way to say if one is larger then the other.

  73. Guys, no no. I’ve seen this before. Of course the cups are the same size. I’ve seen this in a tutorial on how to draw like Julian beever on paper!

  74. The cube gives it away: the right side is not vertical, meaning it was painted on the flat surface, and the artist didn’t do a very good job :o)

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