Quote:Are you trying to confuse me?
If the aperture is f/2.8 and the shutter speed of two systems is the same, ISO will also be the same - the effect will be different because of the multiplication to "the (bloody) same size of picture" - this idea of "same size picture" is wrong!
Why fooling around with multiplication factors and pretend the only thing what counts is a final image of THE SAME size for all equivalenced sensor? One doesn't need to be a scientist to remember the effect of different film format sizes but that shitty waste of time called "equivalence" NEVER mattered in times of analogue film - why this ongoing useless debate today while none of the equivalence preachers can truly deliver the exact equivalence - which also goes for the amplification of different sensors. Who ever said a small smartphone sensor has to deliver the same poster size picture like a medium format?
Working with false assumptions is not helpful
I've never shot film and I can tell you equivalence is extremely helpful. Especially today with the numerous camera systems using various sensor sizes.
BC's explanation above is crystal clear and simple. It's got nothing to do with assumption, it's merely a way of comparing systems in a meaningful way.
It's arguably the best way to compare systems in terms of outputs.