Small camera tripods are 1/4" 20 tpi
large are 3/8" 16 tpi
Once it's spun on you use the twist nut to set it where you need, then just clamp it where you need it. Putting it on a chair or something mobile helps and up and down you just fiddle and pitch the clamp.
As such.
Hope this helps.
Welcome back btw sorry about your father.