I've had this lens for a few months and regardless of what I try (focus adjust, MF, DC, etc.) I just cannot get what I consider to be an acceptably sharp image at anything less than f/4 when I shoot handheld or on a tripod. However, I did manage to get the image a bit better by MF in LV without DC, but it still wasn't impressive and that's not how I want to shoot portraits. I've found a number of threads on various forums from people claiming similar problems, while others claim it is sharp at f/2. But who knows what some people consider sharp. I am comparing to my 50 and 85 /1.8. I really want to like this lens, but I could use some advice on expectations or solutions.