Dr. Jones, My replies in red,
I do not understand your drawings. You have not changed the rotation axis from one scenario to the other, so the box is just as far away from the axis in both cases. Correct, but does not matter. What I changed was the way the camera moves around the axis, to demontrate the difference between a camera recording nightly trails and a camera recording annual trails.
In diagrams 1, 2 and 3, your camera should not be diverging onto the axis, but be parallel with it. As Allen has said, it does not matter what angle the camera is pointed at, as long as you leave it still, it will record a star trail. The difference between different camera angles will determine where the axis is in the picture.
Just like you have in 4, 5 and 6, but here you have not changed the axis! If you change the
axis so as to point towards the box and make the rotor blades orthogonal to that axis, then what is the difference between the mechanism of 1, 2 and 3, from 4, 5 and 6? I believe I would still record the same event, just the center of rotation would appear in a different place on the film. The difference between the two (1,2,3 & 4,5,6)(I wish I had thought to name these better) is the difference between the stationary camera rotating with the axis which will record a star trail and the not stationary camera rotating against the axis which will not record a star trail.
Perhaps you could redo the diagrams and see. I'll see what I can do, to make it clearer.
