Nikon D750 User Manual page 266

To recall lens data when using a non-CPU lens:
1
Assign non-CPU lens number selection to a camera control.
Select Choose non-CPU lens number as the "Press +
command dials" option for a camera control in the Custom
Settings menu (0 323). Non-CPU lens number selection can
be assigned to the Fn button (Custom Setting f2, Assign Fn
button, 0 356), the Pv button (Custom Setting f3, Assign
preview button, 0 361), or the A AE-L/AF-L button (Custom
Setting f4, Assign AE-L/AF-L button, 0 361).
2
Use the selected control to choose the lens number.
Press the selected button and rotate the main command dial
until the desired lens number is displayed in the control
panel.
Fn button Main command
238
Focal length
Control panel
dial
Maximum
aperture
Lens number