Quote:
Originally Posted by multiweb
Like a fisheye lens exposed to all the sky yeah but I just can't visualise how rays that are not near parallel to a closed tube optical axis will hit the mirror at the end of it, with baffles as well, etc... The few that hit the primary sideways would they even bounce to the secondary or miss it altogether?  |
It is about the angle of incident, and angle of reflection, the ray does not have to be perpendicular to the mirror ( these mirrors are not flat). You can demonstrate this with a ray diagram, or a ray string trace running from the edge of the mirror to the opening of the tube on the opposite side. With parabolic mirrors the angle of reflection will be towards the secondary.