yeah, needing to UL this obviously means I had to use it. My BRAND NEW sigma is/was front focusing slightly (by 1cm). So I went through the process of adjusting it in camera and it’s great now! I’m at +10 which might be a tad too much actually. When it was at 0, the back edge of the DOF was where I was focusing (instead of it being centered around that point). Now the focus point seems to be either in the front 1/3 or centered, so I’ll shoot with it like this for a bit before tweaking it anymore. The way I did the adjustment was to focus the lens in liveview, turn liveview off, then hit the AF button and see if the scale moved in the window at all. You want to do this from a tripod with the center AF point centered on the image at a distance of 50 times the FL in MM. So 50mm becomes 2.5 meters. Open the image in a new window and zoom in to “100%”. It’s in focus when it looks like the thumbnail below on the rear LCD on your camera.
Here’s a link to a paper .pdf version as well.
