As a final experiment I decided to rotate the focal reducer leaving the camera alone. I did this by unscrewing it. I am aware that this left it slightly loose but there seemed to be very little slop and any would always be downwards. To be consistent I started with it unscrewed ¼ turn. I've not always got the camera exactly aligned correctly, but I don't think that affects the results.
But first a check on collimation and focus.
|
Betelgeuse on either side of focus to demonstrate collimation, and the Bahtinov picture to show final focus.
|
In the original picture the coma is mainly on the left of the picture and directed to the left.
|
The lens rotated 90°. The coma has moved to the top of the picture and points upwards.
|
|
The lens rotated 180°. The coma has moved to the right of the picture and points to the right.
|
|
The lens rotated 270°. The coma has moved to the bottom of the picture and points downwards.
|
|
The lens rotated 360°. The coma has moved to the left of the picture and points to the left as in the original picture.
|
Home Equipment Part 1 Part 2 Part 3 Part 4
Part 5 Part 7 Part 8 Part 9
