Local Contrast Illusions

This link was over on the Digital Print Yahoo board--thought it might be interesting here, too:

http://web.mit.edu/persci/people/adelson/checkershadow_illusion.html

--Darin

www.darinboville.com

cool.

Strand used principles like those in his printing. He has prints where the highlights appear so glaringly bright they're almost hard to look at, but if you compare them to the white of the paper, you see they're actually quite dark. this let him give the illusion of bright light, without losing a sense of texture and substance. It was all done with relationships of neighboring tones. It's why I almost always like his prints more than Ansel's (he tended to create a sense of brightness with absolute rather than relative lightness of tone, so the highlights were often barely darker than paper base white. Which to me tend to just look like paper, not light light).

John Sexton teaches this effect in his workshops, i.e. to make something appear lighter in the print you don't necessarily need to dodge it, you can leave it alone but darken the surrounding area.

This picture is one of my favorite examples. The effect holds up even in a crappy web reproduction:

http://www.aperture.org/store/prints-detail.aspx?ID=310

I learned a lot about printing from studying the reproduction of this image in a book that was separated by Richard Benson.

Paul,

Have you read Bensons essay in the big Friedlander book - fascinating

I haven't yet. maybe i'll go pick up that book instead of going to the gym ;)

here's a few more

http://www.echalk.co.uk/

select: amusements / illusions