Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: What am I seeing here?

  1. #1

    Join Date
    Apr 2004
    Posts
    832

    What am I seeing here?



    I was selling a lens so I put it face-down on a scanner to picture it.

    Feel free to disabuse me of delusion, but would the image be showing a cross-section (albeit distored) of the elements up to the aperture? I'm wondering if with some modification it might be a way to investiage lenses, possibly showing cemented elements as well.

  2. #2

    Join Date
    Mar 1999
    Posts
    769

    What am I seeing here?

    It sures like that. But my guess is that it is a reflection of the light source in the scanner, perhaps being reflected from multiple surfaces. Cheers, DJ

  3. #3

    What am I seeing here?

    Bummer, if it had been a Jesus image you could have sold this one for a zillion.... :-)

  4. #4
    Scott Rosenberg's Avatar
    Join Date
    Jan 2001
    Location
    The Incredible Pacific Northwest
    Posts
    859

    What am I seeing here?

    this is one of the most cleverly disguised adverts i've seen in a while.

    nicely done.

  5. #5

    Join Date
    Apr 2004
    Posts
    832

    What am I seeing here?

    No Scott, it WAS for sale. It's over. I was reviewing pictures when I came about it.

  6. #6

    Join Date
    Dec 2001
    Location
    NJ
    Posts
    8,490

    What am I seeing here?

    Not enough reflections ...

  7. #7

    What am I seeing here?

    The best rendition of a UFO for some time.

  8. #8

    What am I seeing here?

    The lens has 8 elements in 5 groups, each of the five groups is showing a prismatic reflection from the front of each of the five coated lens surfaces (four of them seen thru prceeding elements). The scanner illuminates the subject with a horizontal lamp off-axis of the sensor path, and the curvature of the lens surfaces relative to the straight light source cause the reflections to be curved and off center to one side of the lens center. You are not observing the cross section of any group.

    I assume the white semi-circle has to do with light going thru the lens from the ambient room light or a white background behind (above the lens) during the scan.
    see http://www.zeiss.de/C12567A8003B8B6F/EmbedTitelIntern/BiogonT4538_engl/$File/Biogon4_5_38_CFi_e.pdf

    Even though the rear elements are as physically as large as the front elements, each groups reflection of the scanning light appears smaller than the preceeding one when viewed from the front.

  9. #9

    Join Date
    Apr 2004
    Posts
    832

    What am I seeing here?

    Terence [...]
    I assume the white semi-circle has to do with light going thru the lens from the ambient room light or a white background behind (above the lens) during the scan. [...]


    Thanks for that.

    Just a small data point: the semi-circular shape is almost certainly a reflection from the shutter, which was closed, so no part of the image could have come from the rear clusters.

    If it would help, I can scan a lens with which others are familar. If I have one.

  10. #10

    Join Date
    Dec 2001
    Location
    San Joaquin Valley, California
    Posts
    9,607

    What am I seeing here?

    Obvious---lenticular clouds ;-)
    "I would feel more optimistic about a bright future for man if he spent less time proving that he can outwit Nature and more time tasting her sweetness and respecting her seniority"---EB White

Bookmarks

Posting Permissions

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