Hi again all
Many thanks for all of your speedy replies , it is now as clear as mud ... only joking guys
I understand it now guy , looks like there a a few ways of setting the system up , with or without calculation , cut out at front or side , cool , the part i was struggling with was if everything is pointing north how do you get to the objects az reading "calculation" , penny dropped with a huge clang , many thank again folks .
Haz