OS 10.14.6

I have a Nikon D750 and normally the f stop is changed using the sub command button ( front wheel ) but now for reasons unknown to me, I change it using the Main command wheel (rear wheel)

I have no idea how this came about. AFAIK, there is nothing in the menus that allow this. Does anyone know how this happened?

jaybass

I have just found that the sub command button and main command button can be reversed for aperture and shutter control.

i must have inadvertently changed sometime. Problem solved