Important! Promptly take note of this.

[Barefoot]

There exist a potential problem with your Nikon F-Mount lenses!

I relate this to you through personal experience. A few months ago, while in a rush, I had a brain fart and somehow managed to turn my Nikkor 16-35mm f/4 VR lens in the wrong direction to dismount. I seem to remember that it didn't want to turn in the correct direction and without thinking, I turned it the other way. It began to move, but I immediately realized that I had done something wrong. The resistance that I encountered told me to stop before I broke something on the lens or in the body or both. Completely perplexed by the situation, I concluded that I had two options and I chose the stupid one by continuing to turn the lens the wrong way to dismount. Luck was on my side from that point on. The lens separated from the body and I held it in one hand and the body in the other. I was much more concerned with the health of the body than the lens at the moment, so I inspected things and mounted another lens. Everything seemed ok.

Later that day I remounted the 16-35mm and again, everything appeared fine. WTF I thought to myself and forgot about it out of embarrassment for having done something so foolish until I saw in the forums of one of the other sites I visit that another photographer had a similar experience with the same lens on a D700. It was there that I discovered the root of the problem.

There is a super small screw referred to as a detent/stop screw on all F-Mount lenses that insures the lens can not go beyond its correct position. That screw was missing on my lens.

To ensure that you never have to endure such a terrifying moment, check your lenses to see if that screw is in place. Here is a link to an image that will identify its location.

Although it doesn't appear to be a common occurrence, it does happen. Don't let it happen to you.