I don't know why but my calibration was way off only a few weeks after I have done the last one.
So I thought there must be an easier way than to cover all optics with paper.
Never really liked the idea of not being able to see properly where on the mirror the beam will hit.
Sure, you can use small pieces and mark them prior to the test but...
Being low on money I did not like the idea of buying an indicator card either.
After a little thought it hit me: Clear sticky tape.
Placed over the optics you can see what you need and still get a nice and clean mark from the laser.
Instead of getting a dark spot the plastic just curls and loses the shine, with a bit more power or a longer test pulse you also get a small hole - but without the smoke and problems of locating this spot on the mirror.
I mark the first spot with a black marker and after moving the axis check where the second spot is.
Find it much more accurate and easier than the paper or sticky note method.
