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Posted on 28/03/13 12:56:58 PM |
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Mariner
Renaissance Mariner Posts: 3007 Reply  |
Amazing Optical Illusions
This site should keep you amused for a while http://www.michaelbach.de/ot/ |
Posted on 28/03/13 1:18:12 PM |
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Steve Caplin
Administrator Posts: 6994 Reply  |
Re: Amazing Optical Illusions
Fantastic collection! There's a couple of hours wasted today... |
Posted on 15/04/13 5:34:18 PM |
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Sjef
Flying Dutchman Posts: 571 Reply  |
Re: Amazing Optical Illusions
Deleted, wrong image. |
Posted on 15/04/13 5:37:25 PM |
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Sjef
Flying Dutchman Posts: 571 Reply |
Re: Amazing Optical Illusions
Nice hyperlink Mariner. The eyes, following my cursor made me smile. In particular “Turning the Tables” I found very brainbreaking: http://www.michaelbach.de/ot/sze_shepardTables/index.html I imported this image in Photoshop and it remarkebly worked like the video showed!! I have a book titled Unbelievable Optical Illusions and most of the items from de site are printed in there. This one (in the book) shows what is often the problem in Steve's Friday Challenges: how to set the perspective the right way. In this example you understand both small figures are eaqual in height (the optical illusion). But when you look at the height of their heads, the big figure maybe is far too small in relation to the figure behind. I hope the lines I've put in tells what I mean. And another point: Steve allways tells us to watch the horizon and put the eyes on the same hight, so this print should be wrong, but when I look at it, it seems right (not the small figure in front of course). So I'm often confused about this matter. Maybe one of the readers have the answer (or maybe Steve himself). 
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Posted on 15/04/13 7:43:39 PM |
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Jota120
Ingenious Inventor Posts: 2615 Reply  |
Re: Amazing Optical Illusions
Well I think you need find the horizon from the viewers perspective. He might be sitting on a chair in this shot. And it should not be forgotten perspective works in 3D space, horizontal and vertical. Specifically the little guy, more we should be looking down at him and the big guy look up to him unless you want to cheat like Michael Angelo's David where in the sculpture he made the head very large to fit in with common perceived perception when looking from below. My quick-take before disturbed concentration (pain) again ..... 
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Posted on 15/04/13 7:57:42 PM |
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Jota120
Ingenious Inventor Posts: 2615 Reply |
Re: Amazing Optical Illusions
Ref: David by Michaelangelo
So we can have reality or perception. I do both. |
Posted on 16/04/13 11:13:40 AM |
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Sjef
Flying Dutchman Posts: 571 Reply |
Re: Amazing Optical Illusions
Yes, vertical is what I was talking about. See the vertical arrows. I interpret I was looking at the big figure straight into his eyes. Perhaps that is the wrong approach. I've increased the small figure in Photoshop to conclude the two men are about equal in height. So how come the figure behind is taller than the pillar, but the figure in front is smaller than the same pillar? So I'd ask myself, which figure is imported wrong? (again, I'm not talking about the small figure at the front). The old Greeks did that perception on their pillars and columns long before Michaelangelo. |
Posted on 17/04/13 12:53:53 PM |
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Mariner
Renaissance Mariner Posts: 3007 Reply |
Re: Amazing Optical Illusions
Sjef, I am continually bumping into illusions of perspective and have given up trying to understand them. Now I just stick to what Steve recommends and things usually look right. Unless I am dealing with very tall buildings I tend to ignore vertical perspective, because mistakes are not very noticeable. None of my Friday entries have leaning verticals because that is the first thing I change, and, so far, Steve has not mentioned that in his critique. The mind corrects the mistakes so that they look right. Complicated shadows at times cause me big perspective problems and nowadays I tend to paint them in and see how they look, then play about until they look right. Sorry I couldn't help. |
Posted on 18/04/13 07:20:23 AM |
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Steve Caplin
Administrator Posts: 6994 Reply |
Re: Amazing Optical Illusions
Sjef, If you look at the pillars to the side of the front figure, you can clearly see they appear to be sloping down as they recede into the distance. This is a clear indication that they're some way above the horizon - and therefore above the eyeline of the viewer. Trace the perspective lines - those on the wall on the left are clearest - to establish the vanishing point, and you'll see the horizon in this image is actually very low (the red line, as I've drawn it here): 
From this, it's clear that the photographer was either very short, crouching or sitting down to take the shot. That's why the eyelines of the people aren't on the same plane as the viewer. |
Posted on 18/04/13 09:07:58 AM |
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Sjef
Flying Dutchman Posts: 571 Reply |
Re: Amazing Optical Illusions
O yes, the vanishing point! A great help Steve, thanks a lot. Now I see that if the viewer would have been standing up, he would have been 'looking down' at the figure in the distance, and seeing the front figure in the eyes. Now I realize I also made a mistake with the red lines. Of course the pillars looks smaller than the back figure because that pillar is further behind him and not sideways to him. With some help of the pillar size I could place the small blue figure next to the hindmost one (valued). Thanks to you and Jota120 I know now the viewer looks up to both figures (his eyes under the horizon), but I don't know which lines to follow so I'd know exactly how tall I should make the hindmost figure. I hope my English is sufficient enough to have made you understand what I mean. Thanks a lot for your answer Mariner 
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Posted on 18/04/13 11:22:47 PM |
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Jota120
Ingenious Inventor Posts: 2615 Reply |
Re: Amazing Optical Illusions
Sjef your English is fine  Thanks. Diversion: Don't ask me to speak Dutch because when we were students in Germany, my Dutch fellow students just wanted to learn English swear words, so in exchange they gave me all the Dutch ones even though my friend and I did not want to know! Its quite useful sometime though as you can swear many places in frustration or pain, apart from Holland , and no one understands!
Diversion over, sorry about that .... On the size of the figures, the pillars are all the same size, so very good clue to get the scale of the figures, excepting we are all different sizes apart from head size similar most times. Have a look at e.g. Nicolas Sarkozy, and 007 Pierce Brosnan, short but head gives it away whatever props they use. I'm quite short myself 5'7". Converse, some very tall people still have normal head size as us all. All I'm trying to say, very useful scaling factor in the general scheme of imagery .... sorry incomplete I have to go ....... |