As it is with Sony tradition, they have announced their new set of ergonomic standards with their most recent lens, which happens to be a 100mm STF G Master.
Unlike other GM series primes, you now have the AF/MF switch from the 70-200GM on the lens barrel. Unlike that lens however,
you also end up with a focus range limiting ring you get a focus range selector which adjusts he optics so you get close focusing capability but you can't focus on infinity anymore.
If you want a focus ring with distance scales on it, you can buy the 90mm Macro. If all you want is the focus button but not the other features, you can have a look at the also newly released 85/1.8, which has that button whereas the more expensive 55/1.8 and similarly priced 28/2 lack it.