Canon 100mm f2.8 macro - AF issue. Is this normal?

Discussion in 'Digital Photography' started by DGrieux, Sep 6, 2009.

  1. DGrieux macrumors newbie

    Joined:
    Sep 6, 2009
    #1
    I purchased this lens two months ago and I took a lots of macro shoots with it in the first few days. However, I haven't used it since few days ago when I tried to take some "normal" shoots: portraits, objects in the house and so on.
    The problem is, if the subject is within 2 meters from the lens, the AF seems to be working properly, but if I move a step further, the lens will just not focus. It's trying over and over again to get something into focus. Some mechanics inside are moving forward and backwards making the same sound as any lens would makes when try to focus on a wall or on a surface without details. Again, if I'm moving close to the subject the AF works ok.
    This happens regardless the position of the focus limiter switch.
    Did any of you have this problem? Is this a normal behavior because it is after all a macro lens?
    Thank you in advance.
     
  2. AlaskaMoose macrumors 65816

    Joined:
    Apr 26, 2008
    Location:
    Alaska
    #2
    Look at the distance switch on the lens barrel. For AF use on close-by subjects, switch to the lower number. For subjects farther ahead, switch to the larger numbers. This switch saves the lens time when auto-focusing. For example, lets say that you are taking photos of a subject nearby (very close). With the lens AF set to a closer distance, the lens' autofocus does not travel or hunts on the far end of the focus range, and then return to the close range. If you are taking photos of a subject that is a lot farther ahead and the switch is set to the number for long distance, then the lens does not have to try to find the correct focus spot on the close-by end of the full focus range. In this case it only hunts for the right focus on the far end of the range, thus saving a fraction of a second.

    When focusing the lens manually, then it makes no difference.
     
  3. someoldguy macrumors 65816

    Joined:
    Aug 2, 2009
    Location:
    usa
    #3
    Just out of curiousity , did you try to focus on objects that contain detail at greater than 2m.? I tried to duplicate your experience with my 100 2.8 and couldn,t . Mine will hunt in dim light when focusing on a dark featureless surface ( the side of my TV ), but thats not a surprise . If you take it outside , will it focus? Will other another lens work normally on the body?
     

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