Can someone tell me how the optic test works please?
From what I can see the four small columns are divided into five sections each with a number on them. I looks like each section is printed with an increasing power from the laser, which results in the column being printed in steps. If there is is any contamination in the optical path the laser ‘flares’ leading to the higher numbered sections becoming distorted and losing surface finish.
If this is more or less correct is it possible to tell which part of the optical path is causing the problems?