Results 1 to 6 of 6

Thread: Afterimage

  1. #1
    Join Date
    Jan 2010
    Location
    Virginia, USA
    Posts
    33

    Default Afterimage

    The post by drlava in 445nM:
    http://www.photonlexicon.com/forums/...al-capillaries
    and the ensuing discussions reminded me of an optical illusion I stumbled into many years ago. I had a darkroom setup in a spare basement bathroom. One night I set off a camera flash in the complete darkness and noticed what appeared to be my image remaining in the mirror. I started experimenting with this and discovered that if the flash were held in the right position while I faced the mirror, I could indeed see a very clear image of myself for approx 10 seconds. I think this is what is referred to as afterimage, and I expect most of you are familiar with it. In my experimenting with it I discovered what turned out to be a really freaky party trick. The person doing it should begin moving their arms around while experiencing the afterimage. They realize they are moving while their perceived image is not. If the mood of the party is right and a few somewhat naive people are in attendance, you can really spook some people. One peculiar thing I noticed is that you have to keep your eyes still and staring straight into the mirror otherwise the afterimage immediately disappears. Fascinating.

  2. #2
    Join Date
    Jun 2010
    Location
    El Paso, Texas USA and Juarez,Chihuahua Mexico
    Posts
    296

    Default

    And what could I say to get these ladies into the bathroom with me? "come into my bathroom I wanna take a couple pictures?" Cool trick but it will take a little planning. Thanks.-jimmy
    Wiki:The first visible wavelength laser diode was demonstrated by Nick Holonyak, Jr. in 1962.



    FS: hi grade SEAL DUST

  3. #3
    Join Date
    Jan 2010
    Location
    Virginia, USA
    Posts
    33

    Default good point

    Quote Originally Posted by jooopy View Post
    And what could I say to get these ladies into the bathroom with me? "come into my bathroom I wanna take a couple pictures?" Cool trick but it will take a little planning. Thanks.-jimmy
    Good point Jooopy. It does take some finesse. Good luck.

    Chuck

  4. #4
    Join Date
    Jun 2010
    Location
    El Paso, Texas USA and Juarez,Chihuahua Mexico
    Posts
    296

    Default

    Whoa it feels and looks like somebodies watching me. Tried alone and almost spooked myself. Not that my own shadow scares me or anything. LOL -I got one of those rubber "body opponent bags" -Bob for practising martial arts and the 1st few days it was in my studio I would freak thinking someone got in.
    Wiki:The first visible wavelength laser diode was demonstrated by Nick Holonyak, Jr. in 1962.



    FS: hi grade SEAL DUST

  5. #5
    Join Date
    Jan 2010
    Location
    Virginia, USA
    Posts
    33

    Default Practice

    Quote Originally Posted by jooopy View Post
    Whoa it feels and looks like somebodies watching me. Tried alone and almost spooked myself. Not that my own shadow scares me or anything. LOL -I got one of those rubber "body opponent bags" -Bob for practising martial arts and the 1st few days it was in my studio I would freak thinking someone got in.
    One more thing I'll mention to you, I found it takes some practice to get the position of the flash just right. If you are at all intersted in further playing with it, I would try holding the flash above your head pointing at various angles toward mirror . . . takes several attempts to find perfect angle. If too direct into mirror the afterimage is just bright light, If too indirect then just a shadow of yourself. When you do find the perfect spot you will amazed (spooked?) by how perfect the afterimage is of your reflection in the mirror. It's almost impossible to convince yourself you are so clearly seeing something that isn't there. It becomes especially weird when you change expressions or move somewhat and see your "reflection" remaining the same. You have to be guarded about not moving your eyes because the afterimage immediately goes away if you do. No idea why this happens, but I suspect the brain anticipates a new vision to be "incoming" when you move your eyes and therefore erases the old one.

    Chuck

  6. #6
    Join Date
    Jun 2010
    Location
    El Paso, Texas USA and Juarez,Chihuahua Mexico
    Posts
    296

    Default

    Hey Chuck there are many optical illusions that are based on the burned in vision and yeah sometimes you got try a few angles. With yours I was able to see detail like my vest but quickly became a shadow like image. 1st try. I love the colors that I see when a flash goes off in front of me. I tell my wife this is the color I want to paint my next car. This blue green yellow red thing I'm seeing lol.
    Wiki:The first visible wavelength laser diode was demonstrated by Nick Holonyak, Jr. in 1962.



    FS: hi grade SEAL DUST

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •