EOS Rebel T3i 18-55mm lens won't take a picture - happened with two lenses

Question

I'm a reporter for a small town paper - Early in 2012 we had a body of a T3i go bad and it was replaced new body and we used the old 18-55mm lens. It worked fine for 7-8 months. I do a lot of sports shots, and I found the sports setting would often cause shots to be blurry, so I started using TV setting with ISO 6400 and a I got better action shots. After several months of shooting this way, the lens stopped working. It wouldn't auto focus in any of the settings and when I pressed the shoot button, it would grind with the camera eventually taking an out of focus shot. It would not work in any of the AF settings.
We had another old lens and I put this on the new body. It worked fine for six weeks and then the same thing happened. Wouldn't focus, grind and take an out of focus pics.
The days before this final breakdown, I took several hundred sport shots over several days. I did not change out the lens or readjust it before this happened. The only other thing I've done over the last year is take sunrises and sunsets without filters. Shooting the sun at the horizon is the most exposure the lens and camera got. This was mostly using the first lens and definitely not with the second lens? Any thoughts as to what's going on would be appreciated.

Answer 1

The grinding noise is an indication that the lens motor is damaged. As mentioned in the comments, manually adjusting the focus while the AF is switched on can damage the AF motor. Certain lenses (usually the expensive ones) have full time manual focus where you can have the AF on and use the manual focus ring without worry.

I have not handled a lot of lenses, but from what I can tell if the AF moves the focus ring or if you can only move the focus ring so far in either direction then it does not have full time manual focus. Conversely, if the AF does not move the focus ring and/or the focus ring can be rotated infinitely in either direction then it does have full time manual control.

Edit: the AF motor does make noise during normal operation, but I imagine that you know what this sounds like by now. This is not the same as a grinding noise that could occur if you cause damage to the AF motor's gears.

Answer 2

You said you have two lenses that are having the same problem. They both exhibit the same problem regardless of the camera body.

I think it is almost certain that the focusing motors are damaged.

What are the exact model of the lenses?

Most 18-55 kit lenses do not come with USM motors. This mean if you forcefully or accidentally turn the focus ring while it is set to AF, you can damage the motor.

This does not apply to more expensive lenses with USM focusing motors.

You do a lot of sports photography, perhaps in AI Servo mode a lot, too. If you can give us an idea how many photos have you taken with the lenses, we can better evaluate if it is simple wear and tear.

DSLR and lenses, especially entry level equipment, will fail after extensive use. AI Servo put the focusing motor of the lens in constant use.

I would not be surprised if two entry level kit lenses stopped working after tens of thousands of shots have been taken.

You did mention both lenses were once working for a period of time. Perhaps you shoot 2,000 photos for one event every day and the lenses simply has reached the end of its life. My kit lens still work after 25k photos or so, but depending on how you use it, the motor can be worn-out. (much faster with the use of AI Servo, too)

Kit lenses are not best known for its durability or reliability. If you get a premium lens, you can reasonably expect it to work for decades. I won't expect anything near that for a kit lens.

A kit lens costs only US$100 so it wouldn't cost much to replace them. Upgrading to a lens with a USM motor will be a good investment too since it offers high speed focusing that sport photography sometime demands.