how to take pics of the insides of lenses

Discussion in 'Lighting' started by darinwc, Jan 23, 2011.

  1. darinwc

    darinwc Subscriber

    Messages:
    2,456
    Joined:
    Dec 14, 2003
    Location:
    Sacramento,
    Shooter:
    Multi Format
    i have a enlarging lens that I am returning. It was advertised as clear but shining a light through it shows a considerable amount of haze and spots.

    I would like to document it so the seller wont balk when I return it.

    however I am having a heck of a time photographing the inside.

    Does anyone have suggestions for how to accomplish this?
     
  2. ic-racer

    ic-racer Member

    Messages:
    7,485
    Joined:
    Feb 25, 2007
    Location:
    Midwest USA
    Shooter:
    Multi Format
    A few weeks a go I did this same thing to return an enlarger lens with "cleaning" marks (from cleaning with sandpaper it looked like :smile: ).

    I held the lens up to a light in the basement ( I use spotlights) and aimed the view throught the lens at the dark ceiling. That way the marks on the glass show up a white on black. With the other hand I snapped the pictue with a digicam on macro. I used manual to bracket the exposure to get one that shows a good the marks very well. It was actually quite easy, and I did a comparison lens and emailed both pictures to the seller.
    [​IMG]
     
    Last edited by a moderator: Jan 24, 2011
  3. Q.G.

    Q.G. Inactive

    Messages:
    5,682
    Joined:
    Jul 23, 2007
    Location:
    Netherlands
    Shooter:
    Medium Format
    In theory, what you can see, you can take a picture of.
    So the way to do it is to put the camera where your eye is/was. May require macro-equipment.
     
  4. darinwc

    darinwc Subscriber

    Messages:
    2,456
    Joined:
    Dec 14, 2003
    Location:
    Sacramento,
    Shooter:
    Multi Format
    I was able to get what i needed.

    I used the tip from ic-racer. The glass surface of the lens was reflecting much of the room. (white ceiling, white bookshelves, brass lamps). That was one obstacle. I ended up using a black card to mask out the reflections.

    Then I used a focused beam from a LED light to illuminate the inside of the lens.

    Finally I found i had to use manual focus so the camera would stop focussing on the front of the lens and focus exactly on the imperfections.

    Thanks all.