This post I will share you 5 diagrams, I made these for you, it will help you to know that clearly.
Including 15 degree higher than shoulder. Under this height, the shooting force almost the same feeling, and good for upward shooting force.
Soft Hand and Hard Hand
Michael Jordan is a hard hand player, his fingers in tense, after shooting, his fingers keep straight and stiff.
Stephen Curry is soft hand player, T-Mac the same, keep wrist relaxing, fingers all cerved.
Shooting From Shoulder
All great shooters shot the ball from shoulder, only do this, you can create a straight shooting force.
This tech lead you shooting arm more close to your eyesight.
Straigh Shooting Force Theory
This theory is the most important. If you realy understand the meaning of it, your shooting training will got no doubt.