How to use the "fixed background" ADF

[FloB]

What's the use of a "fixed background" (compass rose) on the ADF?

I would understand if there was no compass rose and everything and I understand that there are ADFs that have a build in compass - which is obviously more comfortable.

 

But why would I have a background that shows a wrong heading? Am I supposed to adjust the background every time I make a turn? I often get confused by the wrong heading, assuming that it is the true heading. It would be easier to have no rose at all.

 

How would I use that type of ADF correctly?

 

Thanks

Flo