I own a Canon XTI, and it always seems my shots are slightly out of focus. I usual have my camera set to the center focus point, and usually half press the shutter button to establish the focus on the item I want to focus on before actually taking the shot. Yet I still seem to have a problem with a lot of my shots being out of focus.
I was searching around and found out that higher end Canon DSLRs actually have an option in their menu to adjust the auto-focus, yet my XTI does not have this option. I searched around some more and found this page on adjusting the autofocus on a 350D with an Allen wrench. I assuming there will be a similar screw in my 400D?
Can someone tell me what this screw adjusts exactly? Is this something that typically needs adjustment? Should I even mess with this, or should I just send my camera/lens into Canon? I'm no stranger to opening up small electronic devices, so I'd rather not pay $100+ to have someone turn an easily adjustable Allen screw.