This is cheap spectrometer or $9. The slit I think is a little too wide. Unfortunately scale is not readable with my vision. Fortunately, seems feasible to take photos and it’s a bit more readable. Photo above is with my old iPad. Lemme try new iPhone.
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iphone proved impossible. Will have to improvise some sort of fixture for it. Webcam on desk monitor seems more promising. Not sure why I'm getting reflection artifacts. I think interior of the thing isn't nonreflective enough perhaps.
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Getting some diffraction gratings soon. Might try to make my own.
Interesting question… those numbers *say* 4, 5, 6, 7… supposedly 100s of nanometers, but how do I know? What if the experts have been lying to me all along? What if there’s a conspiracy to rig the scale?
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I could calibrate the yellow sodium line with a candle and some salt on a needle, but again I have to take their 3rd for it. Only way is to check the derivation from the grating geometry and measure the grating line spacing myself… supposedly 13.5k lines per inch.
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I vaguely recall learning the operating principles of diffraction in high school. Some shit about waves and angles. But tbh I’ve completely forgotten it. Need to brush up.
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Shits getting serious here
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Optics starter kit. Concave and convex mirrors and lenses, a prism. Can’t find a cheap decent collimated light source. Might have to make one
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Really weird that I can’t find a good broad spectrum light source at home. All my lamps are CFLs or LEDs, and my workshop also has only LEDs. Gonna have to actually find a small incandescent lightbulb somewhere. These things might soon be hard to find.
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Wonder if there are health consequences of spending so much time in narrowband environments.
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Made a lens holder. Idea is to run it on an aluminum square tube to make an optical bench but I got the tolerance of square hole wrong so it doesn’t fit. Lens sits nicely though
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Success! Modified design to be to have a clampable top. Now to make similar fixtures for other lenses, mirrors, light source, screen… I have a cunning plan to bend the light path with right prisms.
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We make progress on diy optical bench. End pieces and 2 lens holders. Next: light source and screen.
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Bought a pair of right prisms and verified the principle of total internal reflection for myself. Now I can use binoculars and trust they’re not a conspiracy. Do your own research.
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I need a smoke machine to do physical light path visualization
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Made a dovetail joint lamp fixture. Will need a box and collimating lens around it, but trying to get basics right. Bulb sits a bit loose 😕
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Used this 5mm copper tape for the connection. This sucks. Connection doesn’t work well. Contact is too light.
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Still, it’s a start. Might reprint with tighter fit. Maybe blob of solder? Will solder stick to PLA?
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Discovered not 1 but 2 embarrassing mistakes. The first fixture was effectively a short since I didn’t notice that the cylinder terminal of the bulb had a ring at the bottom contacting the copper for the bottom nub terminal. Fixed with a bit of insulated tape, and now works fine.
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Second mistake: assumed the bulb has a nearly spherical beam. It doesn’t. It’s like a 30 degree cone, and pointed the wrong way by 90 degrees relative to the light path,
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No idea how the beam is so tight. I guess the weird bulb shape is actually a built-in collimating lens?
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This has turned into a yakshave where I’ve completely forgotten the original point of whatever the hell I’m up to here
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Why am I building a crappy optical bench? Beats me.
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