I don't think this is considered "field of view", but I have a similar inquiry.
I am finding my 50mm is too close to my 40mm & 85mm... plus it is the hardest to use wide open (lowest keeper rate) so I may get rid of it.
What are the "zoom ratios" if that makes sense of these primes? IE, to get the same framing on my 40mm do I basically have to be 1/2 as close to the subject as with the 85mm?
I am trying to figure out what 3 or 4 fast primes might be of use to start collecting, to complement my F4 zooms (probably getting used 70-200mm F4 soon as well)
I was thinking 35-85-135 or something to that extent... no sure how much foot room/running back and forth that would require.