[wim]

Well at least in Canon world, ALL canon L lenses (and some high quality lenses like 17-55f2.8 IS) have the easy possibility of being readjusted, as soon as you remove the mount of any Canon L lens you have shims that are made for readjusting lens centering, it's advised to check centering and adjust it every couple of years, if the Olympus has that then it's truly a pro lens otherwise I wouldn't pay that amount on it, being a pro also has to do with longevity and possibility of advanced service.

 

Of course Oly PRO (and non-PRO) lenses can be adjusted. Actually, you can adjust AF as well, in-camera, certainly in teh E-M1, and AFAIK, in most other bodies as well.

 

Olympus does offer a PRO service as well, since the end of last year.

 

The question is whether you'd want to pay twice as much or even more, for a similar lens in FF. And please no equivalence arguments. Although equivalence wise a lens may have the DoF of a FF lens at twice the aperture number, it still is a lens at that aperture.

 

The only reason to go FF is for more noisefree images in difficult circumstances, or for very high resolution. However, MFT suffers much lens from banding and blotching than most DSLRs do, so from that POV up to 1600 iso and 3200 iso the cameras are easily as usable as with dslrs. In addition, IS with any of these cameras i smore advanced than any other system, so you can easily handhold shots at shutter speeds which are unheard of with non-MFT cameras. As mentioned higher up, no substitue for sports shooting (although the E-M1 comes very close), but certainly great for all kinds of images which do not have a lot of movement.

 

Kind regards, Wim