HogansHeroes wrote in post #16845742
That is one suggestion made by Canon because I never use live view,or rarely.So I am going to try that today now that we finally have some decent weather.
AF settings I have tried them all to no avail.
A static object even on a tripod is still blurry right now taken with the viewfinder
I will try to drop a note here if the live view gives me some clues as to whats going on.
Canon said its very possible i might have to send it in,If so no big deal it works Great with other lenses.
The reason I mentioned Liveview is that focus is done using contrast detection (as opposed to the phase AF sensor, which could need tweaking with MFA).
If a static subject is sharp when focussed using Liveview but soft when using phase AF then it probably needs MFA (though the body+lens combo may be so far out that it's beyond the body's MFA range - in which case Canon may be able to get the body closer to 0, or Tamron could do the same for the lens).
If a static subject is soft when focussed using Liveview but sharp if manually focussed then there may be some compatibility issue with your body driving the lens. Unlikely, unless one is damaged I guess.
If it's soft even when manually focussed then I'd say the lens was probably defective (unless the mount on the camera had become damaged and wasn't parallel to the sensor), but I think you'd mentioned the lens is good on another body and other lenses are ok on this body, so probably neither of those is likely.
If you're going to be doing pixel peeping tests with the camera on a tripod, I'd highly recommend enabling mirror lockup, with either a remote cord or timer setting - as even the mirror slap can result in minor vibrations that'll make a viewfinder shot softer than a Liveview shot (as Liveview inherently has the mirror locked up).