I have a Nikon D5100 with the 18-55 kit lens.
It was working fine till a few days ago. The auto focus used to work from the very next second after turning ON the camera.
But now the auto focus does not start working immediately after switching ON the camera. I have to wait a random amount of time anywhere between 30 to 60 seconds OR have to take a snap or two in manual focus (M) mode after which the auto (A) focusing starts working.
I have not changed any settings between these two scenarios. I have checked and tried various settings after this started happening.
If I have to correlate this to some event, then in most likelihood this behavior began after I removed the lens and mounted it back a few days ago. This was not the first time I did so. Once in a while I do remove the lens to see if some dust has gathered.
Can anyone suggest what might have happened or how to solve this issue?