The autofocus on my EOS 100D (bought in the UK, but the same as an EOS Rebel SL1) has recently begun not working repeatedly. When I press the shutter button half way down, the camera attempts to focus, but doesn’t accept the final position (which I can only assume to mean that the autofocus process has failed), and so doesn't shoot. Occasionally it will work, but it’s doesn’t seem to be consistent. For example, it may work on the first photo being shot after being off for a while, and then no more, or after I change a lens, or do sensor cleaning or a settings reset, etc.
I have reproduced the issue with two lenses (the kit lens and a 24mm canon prime) and have also attempted to solve it by resetting the camera settings and firmware. Sometimes one of these changes works temporarily, but the problem comes back eventually. I have also attempted to clean the sensor using an air puffer, but this also had no effect, even temporarily.
My belief is that there is something wrong with the body’s autofocus sensor (or the software that controls it), since the autofocus works fine when the camera is set to live view mode (and I assume therefore using the main sensor). Does anyone have any experience with fixing this kind issue, or am I destined to have to send the body off for an eye-watering repair bill?
Thanks in advance!
How far away is the subject to the camera? Every lens has a MFD, minimum focusing distance. If the subject is too close, then the camera will be unable to lock focus.
If the camera cannot lock focus outdoors on a bright sunny day on subjects 20-30 feet away, then the camera may need to be serviced by Canon Support.