Do you own a 14-24AFS? I’ve had mine since they were first introduced in 2007. It comes with a Slip On Front Lens Cover which does a great job of protecting the large front element until it gets used alot. Then it just falls off on its own. I had this happen to me so I went and got the LensCoat Hoodie (actually mine is from NPS from long ago). It’s not the same as the plastic cap that comes with the 14-24AFS as its front has some play in it. So I always zoom my lens back to 24mm when I put the Hoodie on. The video above demonstrates just what I’ve talking about. It’s a small thing but it protects a big element!