Wyckoff principle (Extended Response Photography)

Here are the 2 exposures that made up a family portrait I took a number of years ago. Deliberately, I never took a correctly exposed picture. Instead, I took one grossly overexposed picture and one grossly underexposed picture. These two pictures provided me with a much richer description of the scene than a correctly exposed picture would have.

Dark exposure

Light exposure


Composite image

(Fullsize high resolution images are in mannfamily_dark.jpg and mannfamily_light.jpg.)

Notice how the combined image captures both the shadow detail of the deliberately overexposed image, and the highlight detail of the deliberately underexposed image. I call this the "Wyckoff principle" in honor of Charles Wyckoff, inventor of the XR film, black and white film implemented on a color film stock (processed C22).

It's always been a dream of mine to figure out a way to develop the old C22 film (or maybe appropriate C41 to this purpose with some kind of hardner), and do this the more nostalgic (though less practical in today's digital age) way. Let me know if you're also interested in the tradition behind the Wyckoff principle or if you have any leads on developing Wyckoff's film.
Visit The Wyckoff Theory Page

ece1766 skeletal and example implementations

skeletal program pnmwyckoff.c

corrected program example to use as skeletal framework for assignments in chapter 5