Off topic but remember the days when the U.K. used to have a monetary system that had 12 pennies in a shilling and twenty shillings in the pound or eight half crowns in the pound. Oh and we had prices of some articles in things called guineas that were worth 21 shillings!!!!

American visitors who had a decimalised monetary system used to smile, shake their heads and think we were so quaint which we were or was that backward?

There really is no way forward except the metric system. Our kids for at least a generation now look askance when I speak of inches, degrees fahrenheit, gallons etc The kids are right and I am part of a measuring system that has about as much place in the 21st century as King Henry VIII having his wives' heads cut off

Oh and by the way the old way creates problems for newcomers to photography when it comes to measuring things as we have seen and causes mistakes that would be near impossible for a newcomer from the U.K. unless he/she is quite old or almost anywhere in the rest of the world with the U.S. as the major exception.