a1 = release (always shoot the picture focussed or not)

a2 = release

a3 = release

…

a8 = AF-ON only (enabling “Back button focus” & “Focus & recompose“)

a9 = limit 7 AF modus to Single Point AF + GROUP AF, & choose either mode by one click front dial)

…

b1, b2, b3 = 0.5 EV increments always

b4 = EASY EXPOSURE Compensation