Seriously setting the camera focus by numbers?Man I'll just use this script to do this way easier.
Just run the script, while having a camera selected and you will get an locator to set the focus, a blue focus plane and a line to show where the focus is sitting. You can change the visibility of every single one.
Easy to use and does not require any type of installation, just run the script.Tested in Maya 2018, 2019 and 2020.
Please rate it after downloading.If there are any problems or bugs, just email me.
Hope it helps! :)