Lens not focussing

quick query, has anyone had a lens that has stopped focussing?

I have a 16-35 mkI that I have put on two bodies and tried different lenses and the common denominator is the lens. There is no hunting just the focus point flashes but the camera won't take a picture, I have it on the setting that it won't take a picture unless something is in focus.

A few weeks ago it did it a couple of times and now it is a permanent feature???

Try cleaning the electronic contacts on back of the lens. Just moisten a clean cloth with isopropyl alcohol (I think you call it something else on that side of the pond, here in the U.S. we also call the cheapest, widely available kind "rubbing alcohol). Carefully wipe the contacts with that. Keep off the optics of the lens. You also might want to clean the corresponding pins in the cameras, but if the lens fails on two different bodies, chances are it's the lens.

If cleaning the contacts doesn't help, then I'm afraid it's most likely something else in the lens' AF system has failed or some internal circuitry is disconnected for some reason. In this case, you'll have to refer to Canon or an independent repair shop that can handle it.

Alan thanks, I have tried cleaning and think it will need to be looked at properyly

Don't throw anything at me but do you have the switch on the lens set to AF or MF ? Also is there enough light for the lens to focus?

Mike

Mike sadly yes to both of them, I would have to have a long throw to reach you