EOS Rebel XTi Whirring Noise

[ahampton]

I have a digital rebel XTI model and I'm trying to use the auto focus setting on it. I've switched the notch over to AF from M but then whenever I try to take a photo the camera makes this weird whirring sound. I thought something might be broken until I realized the camera has other AF settings that are displayed on the screen. I set it to AI focus as well, still got the whirring noise, and it still wouldn't let me take any pictures. I set it to Auto Servo, it takes some photos, but still make a whirring noise. I tried taking photos in different lightings but It didn't seem to make much of a difference. Any ideas on what I could do to get it working properly? This is my first time using a camera like this so I'm by no means experienced. I'm hoping it's just user error. Thanks for any tips.

[rs-eos]

What specific lens do you have with your Rebel XTi?

[jrhoffman75]

What are you trying photograph and what lighting conditions?

The camera needs sufficient light and a subject with contrast to focus. Set the lens to AF. Set the camera to One Shot and select the center point. Go outside in good light and try to focus on a person’s face from about ten feet away. Don’t use AI Focus. 

[ahampton]

It's 28-135mm

[deebatman316]

What were the shooting conditions like when this occurred. If there is low light or contrast this will prevent the camera from locking focus. Avoid using AI Focus. Use One Shot AF. Also the lens you mentioned supports what Canon calls Full Time Manual Focus. Meaning it's safe to turn the focus ring in AF mode without having to switch the lens to MF. There is a clutch under the focus ring making this possible. You will be able to turn the focus ring to both extremes. This is normal and nothing to worry about.