The focus slop described, is the reason I sent my R-D1 to Epson for repair, referenced in another thread.
Add the typical front focusing and backfocusing to the backlash and it makes for a chancy environment for sharp photos.
RML is right, that proper procedure for focus is approaching focus point from one direction. My current method is to use infinity as reference, backoff toward focus point, go past, then finally focus from near to focus point.
When doing close focus tests, one should have 2 sets of test photos. One from each focus direction. It is possible to develop this method to deal with the backlash issue.
The drawback is either infinity or close focus will suffer. As I move the focus ring toward infinity, the R-D1 moves an stops (with perfect coincident images) perfectly at true infinity focus. But because of any backlash present, it will possibly back focus at close up distances. If the R-D1 was calibrated for close focus, any back focus would cause misfocus far off toward infinity. For me, its more important to have the close focus accurate, as the depth of field gets deeper toward infinity focus.
