What happens is this (refer image 1 below):

- The aperture flex is fitted with a double sided tape to the lens barrel (blue arrow)
- This double sided sticky tape fails and the flex is now loose.
- As you zoom the lens, it bends the flex (visible under the red arrow)
- When you zoom back, the linkage lever catches the flex and rips it partially (green arrow)

Image 2 shows the damaged flex caused by the zoom linkage lever.

This is an expensive repair; to replace the flex the lens has to be completely dismantled.
The lens now has to be recalibrated as all lens groups had to be removed (original adjustments are no longer applicable).

We have come up with a simple and a cost efficient solution to prevent this from happening by fitting a special tape
to securely fix the flex to the lens barrel. It will never come loose on it's own this way.
See image 3 which shows the flex securely fitted with the special tape.

Remember the lens will fail on a job (and it will !) not by sitting in it's case!

Cost of the flex replacement is $720.00 which includes the fixing of the flex to the barrel.