Originally Posted by WISH ONE

Go as deep as you can while still maintaining proper mechanics.
Full range of motion is always best as you want to utilize the stretch-shortening cycle to fullest, but there is a time and a place to train those half reps.
Also consider your goals, are you training to move weight and get strong/er or are you trying to grow vanity muscles?

Chances are if you have hurt your shoulder benching it is because of bad form/mechanics not because of depth. although depth with bad mechanics doesnt make things better.