Aperture - Equivalence or Equivalency?

As most photographers that migrated to the use of multiple formats, 35 mm, 6x6, 6x7, 6x45 and large format 4x5 and 8x10 will tell you they did it for a reason as each format provides unique features. From the fast street or photojournalistic capabilities of 35 mm to the majestic beauty of large format landscapes - different formats provide different pros and cons. There is a reason Ansel Adams, Clyde Butcher, Bruce Barnbaum, etc. only used large format for their majestic landscapes. There is a reason W. Eugene Smith and Robert Capa used 35 mm to bring the news to Life Magazine and to the tables of the American people in photographs.

There is no one format that does everything well. However, the larger format one can effectively use for the job - the better the image quality. Or as one of my former girlfriends cooed, size really does matter. 😎

Exactly, I used 5x4 for static subjects where I wanted maximum image quality, or where I wanted to use lens movements. 120 was a bit in the middle, and I used 135 for my performing arts photography.

But digital cameras are a bit different, I can use my FF camera for almost everything from static Architecture to action. The advantages of each format are a bit more subtle.

Oh, dear, it's started up again. I am resisting the temptation to join in;

www.dpreview.com/forums/thread/4757480

I'm not "resisting temptation" -- I'm not even looking. Were I were to attempt to "join in", I would be censored/censured since "everyone already knows" (including, apparently, the OP who asked). Even if we were to allow an exception for the OP, their question was already answered by someone else just as good, if not better, than I could answer, so there's no point in me replying, too (although, apparently, that rule only applies to me, since there will obviously be tons of replies from other people who were not similarly censored, especially those giving incorrect responses).

Especially true is that posting corrections to others' incorrect responses (either in part or full) is absolutely "unnecessary" and unwanted. In short, correcting misinformation is no different than spam since, as already stated, everyone already knows, anyway.

I am pleased to report that Bill Ferris has jumped in to help clear up the misconceptions. The thread has remained civil so far, and not a peep from the moderators! Praise be!!

Well, Humansvillain should be able to answer his question all by himself, as he apparently owns both systems.
Actually he seems to ponder if he should buy a 150-600mm for his APSC or MFT camera.
And that decision is governed by factors much more relevant to him than equivalence:
- price ($$$ vs. $$$$)
- AF type (PDAF vs. CDAF)

Yes, I am surprised that TC did not post anything in that thread. It hasn't filled 8 pages and is not locked. Maybe something has been learned.