December 7th, 2019 - Optical axis input


Well on my way now on the optical axis input interface. Entering an optical axis boils down to "point, click and maintain mouse button down, drag mouse to second point, release mouse button". Just like drawing a line in any drawing program, basically.

This feature will be heavily documented in video, because determination of the optical axis of a piece of rough is really not that obvious and needs proper guidance, particularly if you're dealing with biaxial stuff.

The great thing is you actually don't need a lot of expensive hardware, since any LCD does the trick - you only need linearly polarized light to determine the optical axis by eye.



If you're not already convinced, grab yourself a piece of Beryl or Tourmaline (easy ones), spin it in all directions in front of a white portion of your LCD screen, and watch the magic happen. Hint : keep the C axis (length of the crystal growth) in the same plane as the screen and rotate it as if it were a clock needle. It will darken and lighten as you turn it if you're not facing the optical axis.
Tom, a.k.a. Ludwig Von Sodabowski