Whilst shooting a couple of days ago the camera shut down with a horrible error message. 'Error 01 - loss of communication between the lens and the body" The lens was only a couple of years old. After doing a bit of self diagnosis it was pretty clear that the diaphragm had stopped operating correctly. The motor that drives this could be heard to be struggling. This apparently is a common failing - even to the point that someone had put a detailed description on how to strip down this costly piece of glassware, not for the feint hearted.
I appreciate the complexities of these lenses and know that he smallest bit of grit is likely to cause further problems. So the lens is being shipped off for repair. For a domestic user, some gnashing of teeth, a grumble at a costly bill, the kids go without food for another week.
But what about the pro whose livelihood depends upon it? This is why it is so important to have a backup when things go wrong. I have the ability to continue, two bodies and redundancy built in with the other lenses I have. I can also call on others to borrow kit if it was a dire emergency. Also access to the pro service channel means a faster turn around on repairs. So the same gnashing of teeth, and the kids still starve, but at least I keep going.
When booking that all important wedding photographer. Ask the question 'If you dropped your camera and lens on my big day, what would you do?" If the answer comes back "Use my I phone probably", then I suggest you walk away - fast.