>>4379017Technically speaking you don't crop to a focal length, you crop to a field of view. You can look up online calculators to do the math for you.
>all I'd need to do is multiply 20*(3/2) for a value of 30mp\Not entirely sure what you're on about here, as you can't crop something and retain/increase the MP count. You can upscale an image but that's a whole other thing and not a common one at that.
>I'm thinking about changing up the way I shoot and switching over from 2 zoom lenses, to 2 prime lensesThis has the potential to make you a better photographer while delivering better IQ and wider apertures. But not if you're going to do what you planned to after it:
>I can cover all of my usual focal lengths by crop in post.Do not do this. This is cropper's cope. You will never get any better if you rely on this. Not only will you defeat the point of using a prime, you'll be getting objectively worse quality out of your shots. Even if you upscaled everything flawlessly without artefacts (good luck), the tigher you crop the sharper your lens needs to be to keep up with the demands.
>It seems like taking a 20mm and cropping to 40mm, you would still end up the compression aestheticWhere have you heard all these terms? It sounds like you've just come off a youtube spree. There's a half truth here:
If you shoot a 20mm lens, no matter what you do in post, you will have the distortion and subject distance of a 20mm lens. You can't undo that. To understand what I mean, go look at some portraits taken at 100/85/50/35/28mm etc. You WILL see a big difference between 100mm and 28mm.
