Oh Dear my 70 - 300mm Canon zoom finally died yesterday aftertnoon. From the moment I bought it it has given me trouble and I had it repaired under warranty in March last year. The problem was the zoom mechanism kept on sticking when I tried to retract the zoom, it stuck out anywhere form 1 cm to 5 or 6 cm. Canon supposedly replaced a part but it continued to have the same problem although much less frequently. It didn't occur all the time and sometimes I could go for weeks or months before it happened again.
Two weeks ago I was using the zoom to photograph my daughter sailing and it started sticking again. Then my camera flashed an error message that said" camera unable to communicate with lens clean contact points" I also noticed that the lens was becoming very hot around the mount so I turned it off immediately and cleaned the contact points and changed lenses.
I pulled the 70-300 out yesterday to photograph some lorrikeets on my back deck and was getting some bizarre readings eg I had camera on 400 ISO and 5.6 aperture (sunny day)and I could not get the light meter to say correct exposure no matter how slow I dialed down the shutter speed. I thought this was odd so I bumped up ISO to 800, same strange response from camera.I tried a few different things before realising that there was a serious problem and putting lens away.
I also forgot to mention that the zoom mechanism has a very strange feel to it now. Off to Canon on Monday morning. I am hoping that as this has happened within 12 months of the first repair they will repair it again for free even though my lens is actually out of warranty now.