I was wondering about one interesting question: How exact is the indexing on Zuiko lenses? It is obvious that a lever on the back of the lens tells the body "how much will the lens stop down". So wide open all lenses should have this lever in the same distance from the locking "pin". I compared all my lenses and there was deviation at most 0.5mm (which could easily be by measuring error). But then there is something very strange: comparing 50/1.8 with 135/3.5 - the movement of the indexing lever between 1.8-2.8 and 3.5-5.6 is supposed to be the same (1.5 stops) but in case of 50/1.8 the indexing lever moves much less than on 135/3.5. I also compared the rest of my lenses - they were OK - 28/3.5 was the same as 135/3.5, and the rest were also OK (35/2, 85/2, 200/4). This is perhaps the problem of only 50/1.8 (mine is a black nosed MC variant without "Made in Japan") This is my hypothetical case: I want to shoot 50 @ 2.8 in manual mode, the lens tells the body that it will stop down by 1.5 stops and the body meters shutter speed. But what if the indexing lever on 50 @ 2.8 tells the body it will stop down by 1 stop? the body recommended shutter speed will underexpose my shot if the lens in fact stops down by 1.5 ! (lever says 1 stop, in fact the lens stops down by 1.5) Or maybe the indexing lever really gives the body correct information, but then the 2.8 designation on 50/1.8 is incorrect and the real aperture at that setting is 2.5 or something like that... So I really wonder: are all those Zuiko lenses really precise in metering? Do they all give exactly the same reading of the same subject at the same aperture? I am asking especially about the 50/1.8.