What is the slope angle of a Gershun tube setup?
Another way to think of slope angle is as half the angular FOV. Essentially, you have a right angle with a height of r (radius) and width of L (distance from aperture plane to end of fiber). The angle is arctan (r/L). Since FOV is expressed as the full angle, the equation uses d (diameter) and is expressed as follows: FOV = arctan (d/L)