I have seen the following calculation in a book.
"For example, for a 50mm lens at f/8 with a circle of confusion of .0001", the hyperfocal
distance is 40 feet. Thus, if you set the focus distance at 40 feet,
everything from 20 feet to infinity will be in focus."
If i calculate using the formula
H = F x F / (f x Cc)
= 50mm x 50mm /(8 x 0.00254mm)
Anything wrong with my calculation?