I used to own the TS-E 24mm II. It was a great lens, and using it was a process that made you slow down and consider things.
But I think your pro photographer friend is right. Modern DSLRs and a really good wide angle (say 9mm or 12mm) will let you correct in post for any shift you want.
Tilt is still not possible even in post, but I found that to be rarely useful at 24mm. For macro it would probably be useful all the time.
Shift shifts which part of the image you are implicitly cropping to. (Every photo is a crop: you’re taking a circular image plane and cropping a rectangle out of it.). Tilt tilts the focal plane.
I occasionally wish someone would make a camera with a circular sensor that captures the entire usable field of view from the lens. If nothing else, a professional camera like this could skip the extra side grip and save some bulk because there would be no need to ever hold the camera sideways.
> I occasionally wish someone would make a camera with a circular sensor that captures the entire usable field of view from the lens.
I've had the same thought, though I wanted just a 1:1 square camera sensor. It could perhaps be "oversquare", so that the corners are slightly rounded off. That wouldn't be so wasteful, since a sensor needs some shaded pixels to measure noise anyway.
But I think your pro photographer friend is right. Modern DSLRs and a really good wide angle (say 9mm or 12mm) will let you correct in post for any shift you want.
Tilt is still not possible even in post, but I found that to be rarely useful at 24mm. For macro it would probably be useful all the time.