Conversation

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.
Image
1
3
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?
1
6
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.
Replying to
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.
1
7
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.
4
6
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
Image
Image
2
5
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.
2
8
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.
2
18
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 😕
Image
Image
1
1
Used this 5mm copper tape for the connection. This sucks. Connection doesn’t work well. Contact is too light.
Image
Image
Image
1
2
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.
Image
1
1
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,
Image
Image
1
1
This has turned into a yakshave where I’ve completely forgotten the original point of whatever the hell I’m up to here
1
4