Autofocus stutters intermittently and requires lens to be removed to correct. When you try to focus on a moving target, it searches back and forth and "forgets" when done enough, where infinity is. The only way to fix this was to remove the lens and then reinstall it. Very uncomfortable. Aside from the autofocus issues, the lens is quite comfortable. Feels like learning. The focus ring has a longer travel than I expected, requiring more than one turn to go from minimum to maximum. There is some