Hello Shooters. For about a month I have been using a new Sigma 50mm Macro lens for the 10D. The lens is very sharp and focuses quite fast for a non-Canon prime lens. The problem I 'm having is when the lens is set on AF and the barrel extends and then withdraws hunting for focus lock, there is a twisting type sound like it needs lubrication. The withdrawal of the tube only makes the sound when camera is eye level in landscape position. Pointing the camera in other positions like downward doesn't seem to make the sound. Has anyone else that has this lens experienced this glitch. I guess if this continues, I will return it for replacement. But perhaps it has a break in period and has to loosen up.
thanks katt
