This weekend we spent a lot of time getting the alignment telescope set up on the super-structure platform. A CCD camera on the back of the alignment telescope allows us to use Francois' nifty software to determine centroids and cross-hair positions for the various points we're interested in.
The paddle mirror on the back of M2 was used to get the tip & tilt of the alignment telescope right...
& the alignment target in the hole in M2 takes care of the decentre.
With the alignment telescope ready, it was time to replace the M5 pinhole carrier & try to find the 2 points that define the optical axis of M5 (the cross-hair on top of the pinhole carrier that represents the pinhole & the image of the pinhole formed by M5).
Here's the pinhole cross-hair...
& here's the spot - the pinhole image formed by M5.
These are all the points we'll need for aligning M5 to M2 - watch this space!