A CD Spectrometer (2006)
I recently got a spectrometer with a fibre input from fleabay, which I've been enjoying playing with.I got a tiny ruby stone and shone a tungsten halogen light behind it -
https://www.anfractuosity.com/files/ruby.png I could see a dip around 694nm like someone else's spectrum - https://en.wikipedia.org/wiki/Ruby_laser#/media/File:Ruby_tr....  This is the same wavelength that ruby lasers emit light apparently.I'm planning on using it to try to measure ABV of beer/spirits.  I noticed some of the cuvette holders with fibre inputs seem to be crazy expensive though, so probably need to DIY that!A while ago I got a little spectroscope that looked a bit like - https://shop.wf-education.com/science/op66595.html.  And simply attached to a camera, to generate graph from.