Afterimage

Here's a neat version of an experiment you probably already know about. Follow these steps:

Open this picture in a browser tab.

Open this picture in a tab next to it.

With the color version open, place your mouse on the tab with the B&W image.

Pick a spot on the color version of the photograph and stare at that spot for thirty seconds to a minute.

Without moving your eye, click on the tab with the B&W image.

Try not to blink. Hold your eyes on the spot on the B&W picture you've been looking at and see how long the effect lasts.

Final step: Marvel at the wonderful weirdness of the human body. (That's a terrific book, by the way.)

I believe this is an instance of what's called "retinal afterimage" or simply "afterimage," and in this case it imposes colors on the B&W image that are complementary to those of the color version for up to 30 seconds.

Cool, huh?

Mike

Original contents copyright 2020 by Michael C. Johnston and/or the bylined author. All Rights Reserved. Links in this post may be to our affiliates; sales through affiliate links may benefit this site. As an Amazon Associate I earn from qualifying purchases.

Book of interest this week:

PhotoWork: Forty Photographers on Process and Practice, Edited by Sasha Wolf
(clicking on the link above takes you to Amazon)

(To see all the comments, click on the "Comments" link below.)
Featured Comments from:

Dunccan: "Wow, very cool indeed."

Darin Boville: "Here's another cool version: If you have an old-fashioned flash, go to a dark room and let your eyes adjust. It should be very dark, you should not be able to see your hand in front of your face. Now keep your eyes open and fire your flash on full power into the room—don't blink, don't move your eyes! Just wait. After a few seconds a ghostly version of the room will appear. Very cool."

Mike replies: I really want to try that but I have neither a dark room or a flash.  :-(

Malcolm Leader: "Bryson's books are always great. The Body is a fascinating and somewhat sobering tour of the human body. I recommend it a lot."

Comments

[Dave]

Similar to the old U.S. flag "trick" with a yellow background field for the stars and green and black stripes.

[JimF]

Here's another fun one. Go in a dark room with your electronic flash. Point the flash away from you and look in that direction. Then trigger the flash with your eyes open and wait. The image will come back to you and persist for a while. If I remember correctly it appears in B&W.

[Enrique de la Huelga]

It works much better if the color photo is negative. In very simple terms, your eye gets exhausted of looking at the same color for 30 seconds, and when you look away the inverse color is over-represented and briefly lingers until your eye recovers it's normal perception capacity. If the starting image is a negative, the BW version will briefly appear in the correct colors.

[Yonatan Katznelson]

Cool...

[Craig Beyers]

Mike...you have a flash on your iPhone camera and you can force it on...

[c.d.embrey]

As far as your brain is concerned, it's all ones and zeros. Sorta like your computer.

Persistence of vision, that's what makes movies work. Stand a dowel on end and shoot a few frame, then lay the dowel on it side. Your brain will provide the missing frames, so that the dowel appears to swing from verticle to horizontal. This is one of the many valuable lesson I learned in film school. Other things are to shorten action shots. Pay attention to what is really happening when you see a match struck, or a bridge blowing up.

[Mani Sitaraman]

"Mike replies: I really want to try that but I have neither a dark room ..."

Mike Johnston doesn't have a darkroom? Truly, we are living in the end times.

[Globules]

The Impossible Color Wikipedia page is an interesting (and related) read.

[Roger Bradbury]

It's possible, with a little practise, to view a stereo pair of photographs and see the 3D view, without a viewer. If you try this trick with a pair of identical photos, it will also seem to be a 3D view.

If you try this trick with a pair of photos that are identical except that one is about 8-10% longer and higher, the 3D effect is increased!

I found this last trick by accident here on TOP, when I clicked on a photo to enlarge it. The bigger version was only slightly bigger than the one I'd clicked on (this used to happen a lot here some years ago) but I tried anyway, with great success!

[Dogman]

I did this yesterday. I think I'm still seeing the effects today.

[BWJones]

Another fun example, here: https://webvision.med.utah.edu/2012/06/your-brain-develops-the-negative/

[dr.roger fisher]

sorry Mike did not work for me at all

anyidea why?

i have the idea that if you had not proposed the effect it would not have worked

[Most likely because you moved your eyes. Try again, and keep staring steadily at one exact spot. --Mike]

[David Elden]

I'm a bit late commenting here but Olafur Eliasson's "Big Bang Fountain" artwork relies entirely on visual persistence. You can find it easily on the web but it consists of a fountain viewed in a darkened room; the fountain erupts and is simultaneously lit by a flash lamp. After the flash the viewer "sees" the water frozen by the flash. It harks back to Edgerton's flash lamp photography (e.g. Milk Drop Coronet and also, to my mind at least, his sinister atom bomb test images - again can find these easily on the web).

Dave.