please explain this weird visual effect

Discussion in 'Photography Beginners' Forum' started by tr888, Jul 7, 2010.

  1. tr888

    tr888 TPF Noob!

    Joined:
    Jul 7, 2010
    Messages:
    5
    Likes Received:
    0
    Location:
    Eastern seaboard USA
    Can others edit my Photos:
    Photos NOT OK to edit
    Although I consider photography an art form, this question isn't about the art: I'm taking crude utilitarian pictures with an autofocus camera (Nikon Coolpix) and encountered something weird (at least to me).

    We are trying to learn who made some silverware passed down in our family, and so I photographed the mark to send a picture to an expert. I haven't sent it yet because the picture is oddly inverted: the engraving shows up like embossing and the embossing shows up like engraving.

    The photos
    (Edit: two pics now in the album; spoon-bowl-up is correct to my eyes; spoon-bowl-down is the weird one).


    The letters STERLING are actually engraved but they look embossed in the picture. The cursive upper-case D is actually embossed in a shallow oval scoop, but the oval scoop looks embossed and the D looks engraved.

    How did that happen?

    Thanks for any light you can shed on this matter. :blushing:
     
    Last edited: Jul 7, 2010
  2. pmsnel

    pmsnel TPF Noob!

    Joined:
    May 26, 2010
    Messages:
    231
    Likes Received:
    1
    Location:
    The Netherlands
    Can others edit my Photos:
    Photos OK to edit
    Maybe you need glasses because I just see the embossed and engraved in the right places... (Or might be due for a new pair myself! :biggrin:)
     
  3. tr888

    tr888 TPF Noob!

    Joined:
    Jul 7, 2010
    Messages:
    5
    Likes Received:
    0
    Location:
    Eastern seaboard USA
    Can others edit my Photos:
    Photos NOT OK to edit
    Is this an optical illusion affecting my eyes and my brain only? :confused:

    On the one I have tagged as weird, does the oval itself look embossed or scooped/engraved to your eyes?
    There are two pics now in the album. Spoon-bowl-up is correct to my eyes; it looks like the real-life actual spoon. Spoon-bowl-down is the weird one that looks inverted (engraved<->embossed, concave<->convex).
     
    Last edited: Jul 7, 2010
  4. OrionsByte

    OrionsByte No longer a newbie, moving up!

    Joined:
    Jul 6, 2010
    Messages:
    1,500
    Likes Received:
    261
    Location:
    N. California
    Can others edit my Photos:
    Photos OK to edit
    Here's how I see each of them, and I'm understanding you correctly, I'm seeing it "right":

    Spoon bowl down: Embossed oval, embossed "Sterling", engraved "D"
    Spoon bowl up: Scooped oval, embossed "D", engraved "Sterling"

    Not sure what you're seeing that would make it look different. There are several cues that point to a light source from top left of the frame, so that means that an embossed feature will be lit on the top left and shadowed on the bottom right, and engraved features will be the shadowed at the top left and lit on the bottom right.

    Embossing/engraving can play tricks on the eyes under certain circumstances, but personally I don't see anything illusory here.
     
  5. Josh66

    Josh66 Been spending a lot of time on here!

    Joined:
    Oct 31, 2007
    Messages:
    14,604
    Likes Received:
    1,236
    Location:
    Cedar Hill, Texas
    Can others edit my Photos:
    Photos NOT OK to edit
    I don't see it in any of those pictures (they all look 'right' to me), but I know the illusion you're talking about.

    [​IMG]

    In this picture, do the letters look like they're raised, or recessed?
    (They are recessed.)
     
    Last edited: Jul 7, 2010
  6. Ashlorraine

    Ashlorraine TPF Noob!

    Joined:
    Jun 25, 2009
    Messages:
    24
    Likes Received:
    0
    Location:
    California
    Can others edit my Photos:
    Photos OK to edit
    I completely see what you are talking about! Thats strange....it is like an optical illusion. It looks like the "sterling" is popping up as opposed to being engraved..I can't even get it to look right in my head. Must be the lighting? Hmm no clue
     
  7. flyingember

    flyingember TPF Noob!

    Joined:
    Mar 31, 2010
    Messages:
    318
    Likes Received:
    0
    Location:
    Kansas City, MO
    Can others edit my Photos:
    Photos NOT OK to edit
    there's too even a shadow so we don't have a frame of reference.

    for example, if there were obvious shadows going one direction we can determine which direction the text goes (in vs out) based on the shadows on the letter.
     
  8. Hartley

    Hartley TPF Noob!

    Joined:
    Apr 4, 2010
    Messages:
    40
    Likes Received:
    0
    Location:
    Phoenix, AZ
    Can others edit my Photos:
    Photos OK to edit
    Hi,

    I think the illusion has to do with the light source - we expect the light to come from above, so the two with the spoon "bowl up" shade the impression the "correct" way, while the other two reverse it. The difference is subtle, but it sure looks that way to me..

    Hartley
     
  9. Dwig

    Dwig TPF Noob!

    Joined:
    Mar 11, 2009
    Messages:
    1,261
    Likes Received:
    0
    Location:
    Key West FL
    Can others edit my Photos:
    Photos NOT OK to edit
    Bingo, the man with the correct answer.

    Without some clear dominant clue about the position of the light source you brain defaults to assuming that light is coming from above as is does most often. When rotate the image so that the light is coming from the top of the print the hallmark looks correct, recessed. When the image is rotated so that the light is coming from below your brain, lacking any real clues, assumes it comes from above and perceives the hallmark as being raised as that is the only way the shadows and highlights would be where they are if the light was coming from above.
     
  10. tr888

    tr888 TPF Noob!

    Joined:
    Jul 7, 2010
    Messages:
    5
    Likes Received:
    0
    Location:
    Eastern seaboard USA
    Can others edit my Photos:
    Photos NOT OK to edit
    I've now been able to cause my brain to interpret the rotated image correctly. :crazy: Sometimes. Cannot do it "at will" yet.

    It is easier to control what my brain sees with the images as thumbnails. But if I click on them to bring out to a larger size, it's much more difficult.

    I should add that turning my monitor upside down doesn't remove the illusion.
     
    Last edited: Jul 8, 2010
  11. tr888

    tr888 TPF Noob!

    Joined:
    Jul 7, 2010
    Messages:
    5
    Likes Received:
    0
    Location:
    Eastern seaboard USA
    Can others edit my Photos:
    Photos NOT OK to edit
    They look raised to me.
     
  12. tr888

    tr888 TPF Noob!

    Joined:
    Jul 7, 2010
    Messages:
    5
    Likes Received:
    0
    Location:
    Eastern seaboard USA
    Can others edit my Photos:
    Photos NOT OK to edit
    Yes, you're seeing it as I do: the embossed oval and embossed STERLING are tricks of the eye. There is no such spoon.
     

Share This Page

Search tags for this page

ground beef pasta sauce

,

weird effects when looking at light source