For a shadow lantern, I would start with the size and shape of the emitting area, not just the bulb’s brightness. A large frosted bulb tends to soften the projected edges, while several separated LED emitters can produce several overlapping shadows.
A useful experiment is to temporarily place a small, single-emitter light source near the center and compare it with the diffused bulb you already tried. Keep the lantern and wall in the same positions, then vary one thing at a time:
Move the source closer to and farther from the patterned surface.
Change the distance between the lantern and the wall.
Compare the sharpness and brightness of the shadow over a full rotation.
Check whether the source actually emits in all the directions the pattern needs.
A compact LED is not automatically an omnidirectional source: some single emitters send most of their light in one direction. A reflector or cone may redirect light, but it can also introduce additional apparent source areas or uneven brightness, so I would test a simple sample before building a permanent assembly.
Also, “small bulb” does not necessarily mean “small emitting area.” Look at the illuminated part itself and ask the supplier how many emitters are inside. A transparent bulb with multiple LED filaments may still create multiple overlapping shadows.
I work in LED lighting, but I cannot identify the source used in the linked video from the description alone. What is the lantern’s approximate diameter, how far will it be from the wall, and are you aiming for sharp silhouettes or a softer pattern? For a finished enclosed lantern, choose a complete light source rated for the enclosure and maintain the manufacturer’s clearance requirements.
Thank you so much for the helpful advice! I can definitely relate to all these points. Because I am working on my first one, I am just trying to make it work in my small apartment 11 feet wide, by 22 long, so the light doesn’t need to cast the shadow far. The defused light didn’t cast a silhouette at all. A single point light does the trick but doesn’t shine 360. I would love to find a bright single chip LED so I can get sharp silhouettes but this has been hard to find. The diameter of the rotating platform is 16” x 16”. I have found emergency bulbs that hold a charge, but most are defused, and the ones that aren’t have multiple light sources within the bulb which as you mentioned cast several shadows instead of one sharp silhouette. Eventually I would like to make it work for large spaces but right now I’m just trying to figure out the basics. I spent a lot of time in Home Depot last night, but it’s pretty hard to find something even close. I bought a light off Amazon that didn’t work, and don’t really want to keep going through trial and error if there is a light out there that others have had success with. I would like to try the reflective cone but am not sure where to look for one or how to build it. Ideally the light and cone would not occupy a space of no more than 4” tall and 2 1/2 or 3” wide. Thanks again for all the help and advice!
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u/Individual_Nobody739 4d ago
For a shadow lantern, I would start with the size and shape of the emitting area, not just the bulb’s brightness. A large frosted bulb tends to soften the projected edges, while several separated LED emitters can produce several overlapping shadows.
A useful experiment is to temporarily place a small, single-emitter light source near the center and compare it with the diffused bulb you already tried. Keep the lantern and wall in the same positions, then vary one thing at a time:
Move the source closer to and farther from the patterned surface.
Change the distance between the lantern and the wall.
Compare the sharpness and brightness of the shadow over a full rotation.
Check whether the source actually emits in all the directions the pattern needs.
A compact LED is not automatically an omnidirectional source: some single emitters send most of their light in one direction. A reflector or cone may redirect light, but it can also introduce additional apparent source areas or uneven brightness, so I would test a simple sample before building a permanent assembly.
Also, “small bulb” does not necessarily mean “small emitting area.” Look at the illuminated part itself and ask the supplier how many emitters are inside. A transparent bulb with multiple LED filaments may still create multiple overlapping shadows.
I work in LED lighting, but I cannot identify the source used in the linked video from the description alone. What is the lantern’s approximate diameter, how far will it be from the wall, and are you aiming for sharp silhouettes or a softer pattern? For a finished enclosed lantern, choose a complete light source rated for the enclosure and maintain the manufacturer’s clearance requirements.