Truthfully I find it quite easy and fast to focus on the bright moon. I use center focus point only, somewhere between ƒ/8 to ƒ/16.0, start with a 1/200 exposure at ISO 200, take a shot or two to dial in my exposure and or ISO as necessary depending on the current brightness of the moon. It's the same process on a tripod, but first line up the center point using liveview to get in the ballpark then turn it off to use the viewfinder. Using my K-3's liveview to focus on the moon @300mm with that lens is not reliable in my experience.
Originally posted by bobbotron Out of curiosity, how do you focus on the moon with that lens? I was trying with the same one tonight, I felt like I could never quite get it right.