Originally posted by Lowell Goudge Obviously you will have manual focus, but if you set the focus mode switch to AF-S the shutter will only trip with focus confirmation (this is usually referred to as trap focus), in AF-C or Manual, the shutter will trip when you press the button.
Whatever you do don't pull a homer simpson like I did with this one. I tried to figure out how to make it work several months ago and never got trap focus to consistently work. I just now figured out why. My body is an ist-ds so I don't know if newer body's are the same. Setting the camera to af-c or af-s in the menu is not enough to enable it. On mine at least, there is an AF/MF switch on the front of the body. It has to be set to AF for trap focus to work, despite the fact that it is a MF lens.
Trap focus can be good if you have a problem manual focusing as it will only take the picture when the camera detects focus. Further, with a moving object, you can just press the shutter all the way, and when the subject comes into focus and focus is detected, it will fire.