If magnetic north lies directly between you and true north, then you’ll have a declination of zero. But in most areas, you’ll have to add or subtract to what your compass reads as north.

Experts from REI do a great job of explaining the basic parts of a compass and how to use them, but here is the breakdown: Magnetic declination is the angle between magnetic north and true north ...

Figure 1: The angular declination hypothesis. Figure 2: The effect of viewing through a pair of 10 PD base-up prisms and the after-effect of adaptation to base-up prisms on judged distance in the ...

The Fairbanks declination I set on my works-with-no-battery handheld compass in 2003 adjusted for a geographic north reading that was 24 degrees west of magnetic north. If I were to find that ...