I removed the top of a CD with duct tape, cut a disk of the clear remaining part of the CD so that it could replace the glass from a crummy chinese moon filter I had in my junk box. This provides a diffraction grating of around 600LPI
Took a photo with my ASI120MC and "all sky" lens of my cell phone flashlight across the room.
below is the result
The difficulty I am having now is trying to find software for spectroscopy. There is RSPec but it doesn't run on the mac.
AstroImageJ is free, and there is a spectroscopy plugin, but I could not get it to actually work, it complains about missing PlotTool class.
Anyone using AstroImageJ for spectroscopy?
BTW I just found a source for 100LPI diffraction gratings for $5 shipped. Will let you know if that one works but it won't be here for a month or so and it may be completely useless.
Edited by Tom Stock, 10 November 2019 - 01:47 PM.