Is this a sudden change whereas everything worked fine before?
Don't know. First noticed isue recently while attempting city skyline from 1 mile+. Prior use was all close in.
There's a mode switch for 1.8m-infinity or 6.5m-infinity near the AF-MF switch. Does it make any difference if you slide this to one or the other.
Made no difference.
Have you tried the lens on another camera body? Cleaned the contacts on the lens and camera?
Yes, both. I may try another round of cleaning. Sending the lens to Canon would be a last resort, having heard too many sad tales.
Thanks, Nick. Very much appreciate the input.
Just some thoughts.
photography -- a compatible blend of tech and art --