Morning Star wrote:
I'm not familiar with your lens (or camera), but I did a quick Google. In one of the pictures showing this lens, there are two switches visible: one is for AF or MF, the other one just says On Off and I can't tell what it is for.
Is it possible that one of these two switches isn't seated properly, maybe not pushed all the way to the position they should be?
A third switch simply says Lock, but again I don't know to lock what?
I looked for a manual on-line, but couldn't find one.
I'm thinking the "lock" switch is for locking the lens barrel to prevent lens creep. You may want to look at how far you are from the subject. If your lens is trying to focus below the minimum focus distance, the shutter will not fire. Since I shoot Canon, I'm familiar with Nikon lenses, but every lens has a minimum focus distance.