Lab frame diagram of a hotspot orbiting in the plane with position vector , where is the unit vector in the radial direction. We note that makes an angle ξ(t) with . The magnetic field is a function of ξ and consists of a vertical plus radial component. The strength of the latter is given by tanθ, θ, the angle between the vertical, and . The observer’s camera is defined by impact parameters , , and a flat space line of sight . The line of sight makes an angle i with the spin axis of the black hole. The observer’s view is shown on the right. Lastly, is the unit vector in the azimuthal direction.