I plan to photograph the solar eclipse (weather-permitting) with both my 4x5 (210mm lens) and 8x10 (12" lens). From my viewing spot in Nebraska, the sun's azimuth will change nearly 80 degrees from start to finish. Does anyone know how to convert that to angle of view when the elevation is 60 degrees above the horizon? (It's not a simple calculation, since the vertical lines converge.) Thanks.