Optical Illusions » Optical Illusions

Hybrid Portraits

david — Fri, 25 Nov 2011 17:40:37 +0000

Hybrid portraits superimpose one portrait on top of another, so that one appears with close viewing, and the other emerges with more distant viewing. Or with reduced image size. Or just by taking off your specs, if you are just a little way away and are seriously short-sighted. Whatever works for you, here Charlie Chaplin becomes [...]

Magic Ring

david — Tue, 27 Sep 2011 07:25:47 +0000

Here’s a movie of a brilliant, double spiral novelty illusion ring. It’s available to buy from Grand Illusions, and on that link you can also see another movie of the illusory effect. As the ring is rotated, it seems to expand when rotated one way, and contract when rotated the other [...]

Hidden Message

david — Wed, 03 Aug 2011 14:49:25 +0000

Can you read the message encoded in the image? A few months back I posted about embedding hidden messages in images. Since then I’ve come across a much better way of doing it, using the lettering in the image above. Lettering? What lettering? You may not even have been able to spot the lettering [...]

Judith with the Head of Holofernes – or is it the other way round?

david — Mon, 04 Jul 2011 14:49:49 +0000

Who owns the body? Judith does to start with, but then Holofernes does, and finally, it’s ambiguous. Here’s a new addition to our series of ambiguous improved artworks. Apologies this time are due to Rubens. I got the idea for these illusions from a print by Picasso. For a downloadable [...]

The Thiery-Wundt and Muller-Lyer illusions

david — Fri, 03 Jun 2011 15:59:58 +0000

Top left is one of the simplest of all illusions. The yellow dot is just half way up the vertical height of the triangle, but looks decidedly nearer to the apex. The effect was reported over a century ago, and has been named for its original researchers the “Thiery-Wundt illusion” by recent experimenters Ross Day [...]

Hiroyuki Ito’s new depth illusion

david — Thu, 05 May 2011 20:44:06 +0000

Do you see an effect of depth as if looking into a tunnel in the right hand spinning pattern? It’s a new depth illusion published by Hiroyuki Ito last year. It’s not all that strong in my example, but it’s certainly there to my eye, and it gets stronger [...]

Sleights of Mind – illusions and magic

david — Wed, 02 Mar 2011 12:18:54 +0000

The dome in the left hand picture is an illusion! It was painted on the ceiling of the Jesuit church in Vienna by Andrea Pozzo a bit over three hundred years ago. Seen from just the viewpoint of the photo on the left, it’s one of the classics of trompe l’oeil painting. The right hand [...]

Truth Lies Hidden

david — Thu, 11 Nov 2010 16:02:08 +0000

A few weeks back the site got a load of US visitors from a link from a discussion on Reddit. Someone got caught out illegally downloading at college, and as a punishment had to produce a poster about the evils of pirating. The poster was to be inspected by the authorities and if approved, [...]

80 Illusions poster – compact version

david — Fri, 24 Sep 2010 16:53:00 +0000

One of our most popular images seems to be the 80 illusions poster. For everyone wanting a giant version, there’s been one available 35 x 23 inches, on our selling site at www.cafepress.com/optoct. I was pleased with the quality of the printing when I got one. Because of the interest, we’ve now reformatted the [...]

Watchful heads

david — Wed, 15 Sep 2010 12:04:25 +0000

I was in a Picasso show recently and noticed the head of a portrait sculpture apparently turning to follow me as I walked past. More on the Picasso later, the movie above is my reconstruction of the effect, using the head of the emperor Augustus (I think). It’s not done [...]