Re: E-3 back focus
I once had my E-3 calibrated. The technician knew what he was doing and did a good job. Of course, the lens you want the camera to be calibrated with has to be left on the camera. Also, if you normally you use a protection filter, leave it on. I had the camera calibrated on a long lens and noticed there was a very slight difference in autofocus with the filter on and off. I figure the slight phase shift through the filter glass affects the phase detect autofocus. These issues don't affect contrast detect autofocus on m4/3 cameras other than the E-M1 when used with 4/3 lenses.
E-M1, 12-40mm PRO, 60mm macro, MMF-3
E-450, 50-200mm SWD, 25mm f2.8, EC-14
FL-50R