What niche subject do you know a lot about?
What niche subject do you know a lot about?
The least temperamental kind to create and display are 540 nm (red) reflection holograms. To create, you get a laser pointer, gut it, turn it on for 15 minutes to let it stop doing funky diode stuff, set up your diorama behind the photo plate, and then shine the laser through the plate onto the diorama for however long your plate takes to develop. And to display it, you just need a point source of light, like a bright red LED.
Compare this with a green or blue hologram, which at the low end needs a high quality laser, a vibration-cancelling optical table, and even with all this can still be ruined by someone coughing in the other room. Or a transmission hologram, which at minimum needs a beam-splitter to create and must be displayed with the same color laser or the scale will be magnified or shrunk a bit, unless you are willing to make a rainbow hologram which also requires either an optical-grade cylindrical mirror/lens or some experimenting with paper slits, followed by a second pass through projecting the master print on the rainbow print.
I’m skipping a lot of details on the setup, but you get the gist. This all being said, the coolest holograms are rainbow holos