I have a question. I have recently played around with a method of aligning the secondary to the focuser and I would like to hear what your thoughts are concerning what I am doing.
I have discovered that by using the LaserMax collimating lasers hologrid. I can use the reflected projection from the diag onto the ceiling as a guide to alignment. I feel that when the projected image is symetrical , equal on all sides, that the optical center of the secondary has been found. (See attached photo Fig. 1 showing the projected grid pattern reflected off the secondary mirror onto the ceiling))
I have had a discussion concerning this idea on another forum with one other person. He feels that the divergence of the laser would cause the hologrid to not fall on the optical center.
I feel that based on the diagram (See picture Fig. 2 showing a laser beam and the primary mirrror cone sharing the same central point and reaching the edges of the mirror from two different distances due to difference in f-ration divergence)
that the divergence of the laser beam does not effect the center focal spot. It seems to me that the hologrid pattern, if symetrical, would indicate that the central point of the grid was indeed falling on the optical center point on the diag mirror. I would think that the grid being equal on each of the 4 sides would be an indicator of the focuser being directly aligned with the diag mirror.
Do you agree or am I missing something in the theory here?
Thanks for looking and any responses would be greatly appreciated.
Floyd
I have discovered that by using the LaserMax collimating lasers hologrid. I can use the reflected projection from the diag onto the ceiling as a guide to alignment. I feel that when the projected image is symetrical , equal on all sides, that the optical center of the secondary has been found. (See attached photo Fig. 1 showing the projected grid pattern reflected off the secondary mirror onto the ceiling))
I have had a discussion concerning this idea on another forum with one other person. He feels that the divergence of the laser would cause the hologrid to not fall on the optical center.
I feel that based on the diagram (See picture Fig. 2 showing a laser beam and the primary mirrror cone sharing the same central point and reaching the edges of the mirror from two different distances due to difference in f-ration divergence)
that the divergence of the laser beam does not effect the center focal spot. It seems to me that the hologrid pattern, if symetrical, would indicate that the central point of the grid was indeed falling on the optical center point on the diag mirror. I would think that the grid being equal on each of the 4 sides would be an indicator of the focuser being directly aligned with the diag mirror.
Do you agree or am I missing something in the theory here?
Thanks for looking and any responses would be greatly appreciated.
Floyd
Attached Image:
[SIZE="Large"][/SIZE][COLOR="Blue"][/COLOR] Floyd Blue
Amateur Imager
