Third Party Lens Calibration Question

Blog › Forums › Photography › Third Party Lens Calibration Question

Viewing 3 posts - 1 through 3 (of 3 total)
  • Author
    Posts
  • Feb 16, 2011 at 10:19 pm #8517
    travis_reynolds
    Member

    Just wondering how many of you out there have had to send a third party lens off for calibration.

    I have a Sigma 18-50mm f/2.8 HSM lens that is suffering from some fairly significant rear focus on my D90.

    Feb 17, 2011 at 12:30 am #72049
    travis_reynolds
    Member

    I got home and did a little focus test on the lens.

    18mm @ f/2.8 (looks to be pretty close)

    50mm @ f/2.8 (the 10mm line appears to be in focus to me)

    This confirms what I have been seeing while taking photos of my son lately.

    Feb 17, 2011 at 12:58 pm #72050
    Avatar photoRoy Conley
    Member

    Travis if you want a reasonably accurate test you must have a high contrast target that is vertical at the focus line. The sloping scale just provides to many focus issues to be reliable at the distances necessary for the focal length being tested.

  • Author
    Posts
Viewing 3 posts - 1 through 3 (of 3 total)
  • You must be logged in to reply to this topic.