^
A scope could say 16x, but the devs could have coded it as FOV/16 (e.g. 90/16 = 5.625 FOV), which will be incorrect and the result would depend on what measurement they use (vertical, horizontal, 4:3, etc). The correct result would be (360 arctan(1/16 tan((π 90)/360)))/π = 7.153. Or the devs could use the correct math, but they calculate it from the default FOV and not the actual FOV set by the user.