Trouble with Focus, Third-Party Repair?
I have a Canon 70-300DO, which I hadn't used in a while and never on my 6D. Today when I mounted it on my 6D I noticed it appeared to have trouble focusing, there was quite a bit of hunting. At first I figured it might be because it was cloudy outside, so I then mounted my 600EX, which has IR assist, and tried some indoor shooting but it didn't seem to make anything better. So I tried using it on my old SL1, focusing was a bit better but not as good as I recalled - LV was probably the only reliable way to focus, but this wasn't possible on the 6D as it couldn't make as minute adjustments as the SL1.
So basically, on the 6D it would hunt and overshoot back and forth, and when it managed to actually acquire focus, about half the time it'd be out of focus - this is very evident without taking a shot - I could probably manually focus quicker and more accurately (which is in actuality pretty slow).
I know, the lens probably needs to make a trip down to Canon Canada, but I want that to be a last resort because 450-500$ to fix a lens (350 is the automated quote value + shipping and taxes). This is quite daunting seeing how I paid about 700$ for this lens - it was working fine back then (as far as memory serves), and I have a new 70-200 F4L IS sitting right beside it - paying that kind of price I could pretty much buy a 1.4x III, slap it on and call it a day.
Is there any reliable third-party that can fix this? I wouldn't mind shipping to the US either if the price is right.