So then I ordered the cheapest fisheye camera lens I could find (49mm wide angle macro, $30) whose smaller lens was just slightly larger than the output lens of the projector. Success! It worked the first time.
(Someone who knew what they were doing might have looked at the focal length and done math to determine what kind of lens was needed. I very much did not do that. But I got lucky!)
I enlarged the various holes to make the new lens fit inside the dome, and got an 82mm to 95mm step-up adapter ring to screw onto the front of the fisheye, to have something I could drill into to hold it in place inside the dome. Then I cut the old electronics housing in half and dremeled out all of the interior greeblies to have a sleeve to slip over the new projector. The rest is duct tape.
I had to open up the new projector to extend the IR receiver into the dome, since, like the old eyeball, it doesn't remember its settings and you have to manually select HDMI on a remote after a power failure.
The image is 16:9 and doesn't fill the whole dome, and it's a little fuzzy on the edges, but for eyeball purposes, it's close enough. Once I get an ethernet cable in there, I'm going to see what tweaks I can make on the image in software to make it fill the frame a little better.
Why to I want a dozen or so of these arranged in a biblically-accurate Xeyes sort of way?
https://www.youtube.com/watch?v=VVDxY0ykLbY
Omg the soundtrack is perfection!
@virtuous_sloth
came here to say I really appreciate the 90s MTV nostalgia trip that is "hobo humpin' slobo babe"
Indeed, that's what made me want to see a constellation of these in real life. Well, once at least.
Herp derp replacing the play button here with "derp" is a wonderful touch, thank you
All URLs should also read as 'herp:derp.derp.herp?Derp'
herp
I’m just glad one of your “thing broke” posts has a happy ending for once
Give it time.
Dude.
Pro tip: buy another cheap projector, so you have a quick drop-in replacement five years from now.
Best news I've read today. Thank you for doing this. Hope the eye keeps soldiering on for years to come!
Glad you have prevailed!
.....So you eyeballed the focal length?
In other eyeball news: Sam Altman's eye-scanning startup is laying off employees https://www.businessinsider.com/sam-altman-orb-worldcoin-tools-for-humanity-layoffs-2026-6
Best news I've heard all week.
Using a step-up ring in this way is a great idea. Stealing that. Thanks!!
Now add the raspberry pi camera and google's landmark pose tracker so its gaze creepily follows your customers around the store.
Actually, the cheapness of the components you used for this make me want to have a go at manufacturing my own. I think I'm going to try buying some rear projection screen film and see if I can can cut it accurately enough to cover a hemisphere.
I wonder if you'd get 'good-enough' results from a thin layer of paint sprayed onto a transparent hemisphere? And I'd get the hemisphere by looking for something like a kids ball, that's packaged in transparent plastic.
anyone pretending to know about lenses will confess just randomly slapping on shit until it looks right is the most versatile operational protocol. measure everything, derive a focal length and be amazed at how you totally fucked up regardless.
also very familiar ui for the projector - i had a soup of these cheap uns wired up. sorry to tell you will need to navigate the menus every time it hiccups... don't understand that HDMI signal and nothing else means STFU AND DISPLAY THIS it helps to memorize the exact key sequence you need to get to the right display config because you won't be able to read it very well
↑ ↑ ↓ ↓ ← → ← → BA
B A ↓ A 【START】【START】
A solution never to attempt for this is to get a robot which will type the sequence for you. If you are lucky, the resulting chain of robots each bootstrapping the next one on power failure will terminate. You are never lucky.
Little zero cost features like this are what differentiate well designed products from mass market. All it takes is for someone to realize the opportunity and ensure that the nine or so lines of required code are implemented.
Lately there have been a lot of digital electronics slop pushed out on the market. These devices are cheap and designed rapidly from very low cost IP blocks. 99% of the chip are just re-used IP blocks (USB, video codec, LCD display driver, etc.) and maybe 1% customization via config settings and microcontroller code. All the design team needs to do is to assemble the top level connections between the IP blocks, and then customize the config and microcode. They are the fever dream of product marketing managers because they can go from idea to product in weeks instead of months. But in haste they often overlook easy opportunities like making a damn projector that can work turnkey.