11-17-2014, 07:50 AM
Funny... I've only just read this review when I was shooting stuff around Moscow on the 16th, around noon. I've come across a bunch of metal trees adorned with lots and lots of "love locks" with a great background (of Kremlin, no less). There I spent about half an hour shooting with a 70-200/2.8 lens. Had to stop down well into the diffraction territory (as much as f/22 at times) to get at least the few locks in focus, while keeping the background recognizable (blurred to hell but somewhat recognizable). Quite a few photos got blurred because of slow shutter speed. I raised the ISO to 800 or even 1600. I thought of what you wrote - if the µ4/3 would've given me a much deeper DOF for the same settings, it would've been nice - I wouldn't have to stop down nearly as much (luckily that was in daytime, so I didn't get capped by ISO).
The way your example would work with mFT is you would set f/11 with ISO 200 or 400 and get the same DOF, diffraction and shutter as on your FF. If ISO 800 on a mFT is acceptable to your eyes while ISO 3200 on FF is not, you would gain a stop on your shutter. The f/22 on mFT is badly plaqued by diffraction, which is typically very noticeable, even to untrained eyes. I thing it is a marketing thing to offer f/22. To me there doesn't seem any benefit from mFT regarding getting larger DOF. Diffraction kills you at the same point.
I like my mFTs but I increasingly wonder about the benefits. Coming back to the Olympus lens discussed here, a 50/3.6 on FF could also be very compact. Though nobody is offering one, and if they would I doubt anyone would buy it. I am wondering whether this is all.
In the end mFT is not your system if the most shallow DOF is your thing - but then FF isn't either. How about 8x10 inch and sheet film?
I hope I didn't write the totally obvious.