How to avoid focus reset when switching to MF on mechanical focus-ring lenses with Olympus E-M10 Mark II?

Question

Usually when one switches from AF to MF on the vast majority of cameras, the focus distance stays distance it was before switching. This way one can use AF to set the focus distance and then switch to MF for taking multiple shots focused at the same distance.

Using the Olympus E-M10 Mark II with lenses having a mechanical focus-ring (as opposed to fly-by-wire which is more common in Micro Four-Thirds lenses), when pulling the focus ring back to switch to mechanically-driven MF, the camera resets the focus distance to whichever it was at the last time manual focus was used!

Is there a way to disable this behavior? And, if not, is this a bug? Is there any case when this would be a desirable behavior? I don't remember any other camera and lens combination working this way and certainly take advantage of the converse behavior quite regularly.

Switching to MF in the camera menu as opposed to on the lens behaves as expected. It takes longer but it is puzzling that both ways of switching from AF to MF do not behave the same.

Answer 1

I think all M.Zuiko (Micro Four Thirds) lenses are fly-by-wire. Even those like the 17mm f/1.8 or 12-40mm f/2.8, which have a part-mechanical focus ring, are actually fly-by-wire.

There is no fix I know of, as these lenses have a distance scale on the focus ring, so switching to MF via the focus ring would render these distances "incorrect" if the lens stayed at the same focus distance as it was in the AF mode.

The easiest way around this would be to assign one of the Fn buttons to switch between AF and MF, or switch to the "S-AF + MF" focus mode, which provides full-time MF along with AF.