Just to let you know I have this lens as well and it will focus right down to the UV filter I have in front of it, there have been times when I have actually tapped on the subject I was focus on with the front lens. Also this lens produces excellent images with my 40D but for some reason not so great with my 50D ( yes I have tried the micro adjusting). Thats my experience with this lens so just thought I'd share it.