Collimation of a Celestron RASA on the artificial star.

Product Description
The artificial star is positioned at a sufficient distance from the telescope. To avoid any reflections, we darken the room.
If not already visible, we expose the tension and compression screws by turning/locking the corrector on the front panel (Figure 1).
Since we cannot adjust/deadjust a Rasa using the eyepiece, we need a camera to provide us with the image information from the diffraction disks.
To achieve focus, we use appropriate T2 adapters.
Now we bring the star disk to the center of the camera. Then we defocus slightly to simplify adjustment (Figure 2).
We loosen and lock the collimation screws in small steps, while simultaneously monitoring the live image from the camera on a screen.
If the shadowing leaves the center of the diffraction pattern, we work in the opposite direction from now on.
Once we are satisfied with the adjustment and we see a symmetrical diffraction pattern both intra- and extrafocally, we finish the adjustment.