Cees Mutsaers
Veteran
Yes when it is sharp at 10 meters and i want to get something sharp at 11 meters or more I have to turn the focus ring about 1 mm
Something is very wrong - back focus set quite a bit away from optimum would do this easily - even with the lens opened up to 2.8 the difference between 11 and 10m is not really a lot.
One thing you could check - how close to the distance markings on the lens are you - if you are wide then with the image sharp (which you've said it is at 10m) is the focus ring on or near to 10? The rotation to go from 10 to 11m is quite small.
Being frank - you need to get the camera checked by the dealer or somebody else who's camera experience is deep. Only then can you start to work out what is happening. It's kind of like we know you're ill, but the symptoms are just 'not well'