This is the view after making adjustments to the main mirror.
The Cheshire function of the TELECAT shows the centre spot triangle
perfectly centred in the Cheshire ring and the sight tube cross hair
perfecly centred over the centre spot triangle on the main mirror.
For many applications this level of collimation is quite adequate but for
truly perfect collimation the INFINITY autocollimator is necessary.
CATSEYE Collimation systems: