How many steps difference?
If you get rid of your 75mm and 85mm lenses you'll never replace them by walking forward with a 50mm lerns. Perspective (what's in the background) will be very different.
But here's an idea -- you own the two lenses. You own two feet, presumably.
Get up from your computer, put the 28-75 lens on the camera, focus it at 75mm and then a 50mm, and actually look through the viewfinder.
Try this for a subject inside your living room, and for a subject across the street.
- Canon EOS M58.8%
- Panasonic G85/G803.3%
- Panasonic FZ2500/FZ20001.9%
- Panasonic LX10/LX151.2%
- Panasonic GH5 development3.6%
- Sony a99 II15.9%
- Nikon KeyMission 170 and 801.0%
- Fujifilm GFX 50S development28.3%
- Olympus E-M1 II development18.7%
- Olympus E-PL80.1%
- Olympus 25mm F1.2 Pro1.5%
- Olympus 12-100mm F4 IS Pro1.9%
- Olympus 30mm F3.5 Macro0.1%
- Sigma 85mm F1.4 Art3.6%
- Sigma 12-24mm F4 Art2.6%
- Sigma 500mm F4 DG OS HSM Sport2.4%
- YI M12.2%
- GoPro Hero50.8%
- GoPro Karma drone2.2%