I decided to build my second spectrometer. I built a box, long and wide enough for me to put a Canon IXUS 120 camera and be able to adjust angles, slit:grating length, and for future projects play a little with collimating lenses. The slit is made of two razor blades.
I used Canon IXUS 120 with a removed IR filter, grating set at 30cm distance from the slit, angle about 50 degrees. ( I say "about" because I have so far not been able to measure the angle, need to invest in a protractor.) The grating is set to 0,5cm away from camera lens with the possibility of angle adjustment for finer focus. The slit in this CFL reading is set to about 0,08mm.
Question: Why do I see multiple blue and green spectral lines? If you look close at the 405nm line it has more lines right next to it? Same thing with the second blue and the bright green. Are the lines supposed to be there or is this some unknown to me effect caused by a too narrow slit? Light reflection from the fine edge of the razor blade? When I make the slit wider this phenomenon dissapears. Thanks and greetings from Sweden, Martin
Black fleecefilt on the inside.
Opening for a webcam USB port. .
Here I added a metal plate and more black filt on top.
The idea is that I can attach a small magnet to the camera and be able to change the distance or the angle by simply sliding the camera on the filt. The magnet is 3cm away from the camera body and just strong enough to keep the camera steady and firm.
The slit job was a fast work in progress, I wanted to test my new creation as fast as possible.
These are the CFL lines. The additional lines are to the right of 405nm and the 435nm lines, and the green 538nm has additional lines to left? There are also extra lines in the 465nm region, faint but they are there. Is it supposed to be like this? Try zooming in if they are hard to see.
Link to SpectralWorkbench graph https://spectralworkbench.org/analyze/spectrum/10457