I think that people who shoot FF are often trying for max IQ. Thus, a FF photographer probably would not want to stop down past f/22 (f/11 on mFT) due to the effects of diffraction softening. Instead, they would opt for
focus stacking. Otherwise, even mFT is even overkill, for DOFs that deep, and many compacts will do as well in a smaller, lighter, and less expensive package.
You will notice I said much easier, not that it can't be done.
It's easier to get DOFs beyond f/22 on FF, but such DOFs are well into diffraction softening territory. So much so that...
The 60mm macro on an E-M1 can give you spectacular results without resorting to focus stacking for other means.
...it doesn't matter how sharp the lens is at that point -- diffraction will rob it of most of the resolution advantage it had over even mediocre lenses by that point.
By the way, any macro lens on any FF body can also "give you spectacular results without resorting to focus stacking for other means."
I've actually done all the ones I've tried so far handheld.
I'm also thinking macro photographers going after max IQ aren't often going to reach that goal with handheld shooting. That said, I shoot macro handheld all the time, and, if I do say so myself, get some decent results.
That simply would not be possible with a FF camera (believe me, I tried with some Nikons).
I am guessing you are talking about the utility of IS for macro shooting. I've not heard anything about Olympus' IBIS at macro shooting distances, but I'd be rather surprised to learn it was as, or more, effective than the IS in Canon's 100 / 2.8L IS macro.
Regardless, I wouldn't take your success with mFT and lack of success with Nikon FF as evidence of mFT being superior than FF, but I would take it as evidence that mFT works better for you.
So it's not a matter of ultimate technical quality, it's a matter of balance between quality and ease of use.
Well, I take the occasional macro, and the number one issue I have is when even the slightest breeze keeps moving the flower or leaf I'm shooting. Aside from that, there are no "ease of use" issues for me using FF in macro shooting other than the uncomfortable positions I sometimes have to get in to get the angle I want.
Just for kicks, this was handheld:
Canon 5D + Sigma 70 / 2.8 macro @ f/4, 1/125, ISO 400
I don't doubt for a minute that someone else could not have done just as well, if not better, with an EM5 + 60 / 2.8 macro at f/2.8, 1/125, ISO 200. On the deeper end of the DOF spectrum:
Canon 5D + Sigma 70 / 2.8 macro @ f/11, 1/100, ISO 100
I suppose a different person would have shot the same at f/22, 1/100, ISO 400 for a more DOF at the expense of greater diffraction softening, but, either way, in my opinion. If, for some reason, you are of the opinion that what the shot needed was f/22 on mFT (f/45 on FF), then let's just say we see things differently, and that, sure, if that's the case, mFT will suit you better than FF.
However, as I said, a compact might even suit you better still.
!
