Upload & Sell: On
Hi - this is a known issue with this lens. Basically the ribbon cable that allows communication between the lens and the camera body is bad...and this is known to Canon except they will not admit they manufactured a bunch of lenses that have problems - whose owners after about a year or so of having the lens suddenly cannot get AF (often at close distances) or get a proper exposure at anything more than F4-F5.6...stopping down to F8 and beyond you get an overexposed mess of an image.
Apparently Canon had a run of bad ribbon cables in this lens. I had this problem too - do a google search and you will find info on it (Luminous Landscape had a discussion about it in their lens/camera forum in summer 2010 or so.)
Luckily for me, I had just purchased the lens as a refurb from Canon...but the 90 day warranty had just expired (by about 20 days). I called their tech support 800 number and pointed out that this is a known problem that many people report (and that Canon refuses to admit the problem). The 800 number folks could only say to send it in for tech support in New Jersey to look at...
So I sent the lens in with a detailed explanation of the problem and again pointing out that many people complain of this issue on the net...and that please please Canon, fix it for free (because it was purchased as a refurb and this should have been fixed by Canon when they had it, and it was only 20 days or so out of warranty).
Bottom line - Canon fixed it for free and sent it back to me with no charge for postage.
If I had to pay for the repair it would run about $300 or so, perhaps a bit less. Sorry (my apologies) - just thought you might want to know info such as estimated repair cost...
Anyway, do a google search and this issue is discussed on the net. Good Luck! Send them a letter with supporting evidence from the net. This is something that is likely so widespread that Canon would take a big hit if they had to replace all the ribbon cables on this lens for most everyone - but they need to do what is right here for those people whose lenses develop this problem.
Robert DeCandido PhD
Update 1: "To anyone who is having "Err 01" problems on his Canon try this to determine whether it is really sticking aperture blades or dirty contacts: Choose a high aperture like f/11 or f/16 and press the dof preview button. Look at the aperture blades through the lens. You'll see them stopping down. When you release the button the blades should open up again. If they don't or they only partially do, it's sticking aperture blades." --- from a suggestion on a web site.
Update #2: see this discussion:
and the associated video.
Update #3: see this discussion at Luminous Landscape:
Update #4: for anyone in Australia, read this - it might be cheaper to send the lens to the USA and have it repaired here:
Anyway, this is an issue that the FM community could do a Poll on and send the results to Canon - so that one of the largest photo groups gets on record to Canon that the 24-105 has issues and when someone has the problem Err 01 it should be fixed for free or at a greatly reduced cost.