Yeah you nailed it on your response, I just wasn’t getting my head around it. The one thing I like about the crop mode is that I can frame it correctly. If I’m shooting my 24mm as a 35mm and just decide to crop in post I can’t be sure of my framing whereas the crop mode allows me to see it in camera when I take the shot. With the 60MP on the a7rV I’m still getting a fair chunk of MP even in crop mode
This is why my preference is primes on high resolution FF bodies vs zooms. You can always shoot wide and crop in post to get the desired look, provided you have the MP and noise overhead to work with. I don't necessarily mess with crop modes though since I want a wider frame to work with in post....The stuff I shoot, I don't really get a lot of time to frame things correctly in the field....just shoot wider than needed and correct framing in post, but its definitely a mental habit you need to set when shooting. This also gives you more of the frame to work with to straighten and correct geometry/perspective in post. I can get a lot looks in terms of FOV out of a 24, 35, and 85. Shooting Disney architecture stuff with 4 kids in tow...lol Sigma 14-24 on the wide end while walking and correct it later.
This is also why I tend to skip 50mm lenses. I can achieve the look with a 35 pretty easily and if I want a super fast aperture medium telephoto type shot, usually 85mm @1.2 is a more pleasing look.
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