I hadn't used my 50-150mm 2.8 since the first of the year . At that time , it was working fine . But I took it out the other day and now it seems to be off . It seems to be front and back focusing, Other times , I can't tell what the heck it's doing ! In other words , it's all over the place .
I think the warranty runs out this month , I'll have to check . Tomorrow I'll mount it on a tripod and check it out more . I'll also clean the contacts
But I can't figure out how a lens can go from working great to this . Surely lack of use is not the cause. Any thoughts ?