I now have a red forehead
It all fits together so nicely when one knows what is going on. I now know that:
My sensor size, 22.2x14.8mm=3888x2592 pixels=1.5=.6666=3:2=6x4
And, I can easily convert from one measurement to another.
I also see why most people say “6x4” rather than 4x6 as I usually do.
Again, thank you!
Arvid