Optical Illusion - Lost in Perspective

This is another classic optical illusion. The name for this is the Ponzo illusion and has a lot to do with our perception of distance and using cues from perspective to judge an item's size.

Enough chitchat for now. Look at the image below and guess which yellow line is longer.

Step 1: Get an image with perspective

OK, all images have perspective, but we want one where many lines are converging to the same vanishing point. In this picture that vanishing point is right above the end of the escalator.

The source image can be found here on Flickr.

Comments

[Magnelectrostatic]

Uhhh, the lines all look the same length.

[shooby]

Yeah, same for me. I do several perspective drawings per week, so maybe I'm just not affected. I'd experiment with different patterns on the surface that these lines are on.

[mdgnys]

its like the one with the paper plates their the same size but look different because their curved!

[PKM]

I agree- in the last image the illusion is pronounced but the bridge picture doesn't really have enough strong linear cues. You might be better off with a higher-contrast image or a photo with more linear perspective (looking down city streets, for instance).

[hg341]

look at the last pic with the black lines i noice the effect good job

[craig3]

when you look at them all over wit the black lines it kinda looks like the length change but when you look up and down the lines one at a time, the illusion doesn't work

[ItsTheHobbs]

yeah.....

[Davo250]

They all look the same length to me anyway :/