the beam at the tube exit look like this —>
shadow is quite clear and sharp (reletively)
light diffusing over the top of the structure like this —>
shadow is very blurred because the diffuser have many surfaces with different angles
someone had done similar style in a bigger scope:
shadows generated by this structure, left and top:
the shadow of this shade is still quite sharp, because even though it has some structure, the surface angles are still very limited, photon bouncing trails are almost the same.
paper structure:
I record the screen but tbh I don’t know how to explain. also the setting is behind me there is a big natural white (yellowish) kitchen ceiling light.