Originally posted by Larrymc
This feature is exclusive to some Pentax lens, not all. Most auto focus lens focus rings can only be turned if the camera is set to manual focus. Quick shift allows you to make adjustments to the focus without switching to manual focus on the camera body, this is especially useful for situations where you are very close to the subject and the AF system can't quite get the focus or you have placed the subject in a position other than the center of the photo and you don't want to move the focus point in the viewfinder. Quick Shift is very useful if you use live view and the focus peaking feature of the camera. Somewhere on Pentax Forums there is a chart with Pentax lens features but I can't find it at this time.
If I focus outside of center, I focus on-center, then flip to MF, and slightly rotate my camera so the original point of focus remains. I am trying to figure out how quick shift, benefits. Can you help me? Don't want you to think I am being critical how you accomplish this - your photo is greatly appreciated. On the contrary, I am a duffer. I am trying to learn.