Setting up the alignment telescope

With M3 clean, our next task is to prepare for the CGH tests...  The first test will use the big (210 mm diameter) CGH to check the surface figure of M3, then the small (148 mm diameter) CGH will be used to align M3 to the rest of the mirrors.  More about that later - for now the first step is to get the alignment telescope set up on the optical axis of the corrector.

A camera on the back of the alignment telescope provided this rather unusual view of the alignment telescope (in its mount) reflecting off the aluminised spot on the M2 null lens!

Some fiddling to get the alignment telescope centred up on the laser from the interferometer down below...

Here we have Ockert & Martin sporting their uber-stylish laser safety goggles - great smouldering look, without the fried eyeball... nice ;)