I was invited in to a house where the family was of short stature, averaging about five feet. I noticed all the pictures appeared to be hung quite low by my standards. I found this amusing. I also had the good sense to keep it to myself.
There is no standard, but the "best" results are eyelevel based on the family or most people that would be looking at it. If your family has members between 4'8" and 5'6", the photographs in the home would be lower than for a family ranging from 5'9" to 6'6". Neither would be wrong, it is what would be best for each household.
Warning!! Handling a Hasselblad can be harmful to your financial well being!
Nothing beats a great piece of glass!
I leave the digital work for the urologists and proctologists.