Why won't my new Canon Rebel T3i take a picture with the 18-55mm lens in autofocus mode?

  • I just purchased a brand new Canon Rebel T3i kit from Costco.. I used it for a couple of days, but now when I have the 18-55mm lens attached and the camera on auto-focus, it will not take a picture. Still will take a picture in manual focus. And will take a picture in either focus with the other lens on (55-250mm).

    I've been told by a friend that the lens may not be seating right. Are there any other settings I can check? I am very new to the camera and I probably messed with some settings or accidentally bumped something I shouldn't have.

    Or I can take it back to Coscto and exchange it.

    Have you tried focusing in live-view?

    Try cleaning the contacts on the lens and lens mount.

    did you hear the click it makes when the lens is completely fitted to the camera? also, i am not really sure, but maybe the camera wont take the picture if it's on AF mode and the lens can't focus (i.e. you're too close or too far)

    I've tried taking pictures with that lens in really bright light outside, close and distant, and it still will not shoot a picture. I don't know what focusing in live-view is but I can look it up and try that.

    Had my T3i for over 3 weeks, no problems, then today I started experiencing the same issue. Must be a defect in the line. Going to see if I can get a replacement as it is only 3 weeks old.

    I ended up exchanging the camera for a new one... new one is working fine.

  • Troubleshooting a lens:


    • Toggle: Make sure the toggle on the lens is firmly in the AF position.
    • Contacts: Check the metal contacts on the lens to make sure they are clear of debris and are clean.
    • Ring: Make sure the focus ring isn't obstructed. It should move freely when on MF and become more firm when on AF (for your lens, not all lenses do this).


    • AF Setting: Select center point focus (this is your most accurate point of focus on the T3i) and attempt to focus via viewfinder)
    • If you have a confirmed focus (beep or solid red light in the VF), then the problem is in the camera.
    • Attempt to focus via live-view. If this works, then the problem is in the camera's phase AF (live-view uses a different, more basic system) and the lens and contacts are fine or the shooting environment.


    If the camera legitimately cannot find a focus when on AF mode, it will not fire. This is usually caused by the camera not being able to determine distance to the subject. A solid color wall, or a very dark environment can cause this. This can also be caused by being outside of the focus range of the lens (usually too close).

    If you haven't been able to solve your issue, here's a troubleshooting entry by Canon. I also found a post saying this behaviour can be caused by "mirror lockup" (is this the same as live-view?). Anyway, please let us know if you managed to solve it (you too, @Kenneth).

  • I had the same problem. I fixed it by removing both battery and the card

  • I had this problem and discovered that the very end of my lens was slightly stuck...I gave it a gentle twist then it worked great :)

  • I had the same problem, which turned out to be the camera was trying to focus on a dark, nonspecific area and couldn't lock into a particular subject. You can tell this is happening when the auto lens continually tries to focus moving back and forth, but can't focus on anything. In my case, I was trying to take a picture of my dark dog lying on a print rug in a dark living room.

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Content dated before 7/24/2021 11:53 AM