The days of cathode ray tubes, or CRTs, are firmly behind us, and that’s generally a good thing. Display tubes were heavy, bulky and fragile, and needed complicated high-voltage electronics in order to work. But not all of them were actually large: miniature display tubes were also produced, for things like camcorder viewfinders, and [Tavis] from Sideburn Studios decided to turn one of those into a slightly creepy art project.
The heart of this build is a one-inch CRT that was salvaged from an RCA video camera. [Tavis] mounted the tiny tube inside an acrylic box on a 3D printed base. Inside that base sits a Raspberry Pi along with a high-voltage driver and a power management board. The Pi continuously plays a video that shows a human eye blinking and looking in various directions. Just an eye, floating in space, looking at the world around it.
The magic is briefly lost when the Pi starts up, because it then shows a microscopic version of the Pi’s standard bootup sequence, but once the thing is running it adds a weird vibe to a room. It actually looks like something you’d find in an avant-garde art exhibition — in the video (embedded below) it’s accompanied by eerie music that gives it an even more unsettling feel. Electronic eyes are always a bit scary, especially when they’re actually looking at you.
Display tubes were heavy [CHECK]
Display tubes were bulky [CHECK]
Display tubes needed complicated high-voltage electronics in order to work. [ehhmmm… CHECK?!?!]
Although… what’s complicated, just a relatively stable high voltage, a few transistors and a flyback. Sure some deflection circuitry needs to be added too and lot’s of other parts… but doesn’t any circuit. A lot of things in more modern display technology is integrated in a single chip these days, so you can’t see it… but does that mean it isn’t complicated?
Display tubes were fragile [hmmm… where does that come from?]
I never encountered a CRT that was damaged because it was fragile. Sure it took some special skills and effort to make, but this is also the case for all other kinds of display technology. And I’ve seen many damaged LCD screens in my life and I’m sure I will encounter many more.
Regarding the project, fun project. I like the display being the center of it all an ode to the technology. Regarding the video, I loved the mysterious eye being displayed on the CRT, very awkward and spooky, but I found the ending of the video, especially the last 23 seconds of it just a bit too dark for me. I just couldn’t watch it. I hope not to see anything like that again in future videos, it felt a bit like I missed something. But that could be just me.
Well cased they are not terribly fragile from the front… unless forces displace them in the mount and the Achilles heel fragility is tapped… the neck.. you can bounce a finishing hammer off the screen but can crack a neck by slipping a screwdriver. Also filaments are very vulnerable to shock when hot and fairly vulnerable when off, as are aperture grilles etc. They also do not like external magnetic fields.
I’ve ruined a CRT by bending one of the pins a wee bit too far. CRTs are fragile.
LCDs and OLEDs are pretty fragile too, but the shape and mass of an LCD or OLED makes it a lot easier to protect them with a simple frame, or gluing them down to a flat, rigid surface.
Thanks for your comments. Regarding the end of the video it just goes blank for the cards to show up but it’s too long and had some editing mistakes.
These CRT viewfinders are cheap and abundant. I’m surprised we’ve not seen more hackery around them. Nice clean simple enclosure. I always get stuck on the enclosures. Nice job!
If only those tiny crt were in color, I always tought they would be perfect for miniature arcade built (except for the lenght maybe)
Apparently they exist. Just haven’t found what camera models they are in. They showed up sometime between transitioning from crt to lcd so it’s hard to find a color one that’s not an lcd.
Yah, think it was somewhere between the tube makers “Hahah, we’re the only game in town $400 a piece please” and “Oh crap, there’s competition, better shave that margin a few dozen percent.”
The colour ones had a rotating RGB filter disc between the lens and the screen.
I have one of those color tubes. It’s beam index, and came from an RCA CKC021 camera
I messed around with one and a camera that was old enough to have adjustable scan rate and aspect ratio. Ultra widescreen video (2 to1) camera to that little screen. Something normally never seen. No black bars or cropped image.
Another idea has been to make one into a vector scope for stereo audio monitoring.
This is excellent! I like retro up cycling. Now how about this… Put 4 of them in a row and with additional coding you have a CRT clock. You could even have the code change number fonts for AM/PM or do a CRT word clock. Just a thought…
> The magic is briefly lost when the Pi starts up…
I guess there’s ways you could “hide” much of that. Or maybe embrace it and call it the Raspberry PEye.
Or make it viewable by only one person at a time and calling Raspberry Private Eye.
The perfect final touch for this would be a little red theater curtain around the box, which closes when the Pi shuts down or is turned off, and opens when the Pi is finished booting.
Maybe, behind the curtain and in front of the plexiglass box, put a small tank of gently bubbling fluid and tubing, so that when viewed through the opening in the curtain, it looks like the CRT is in the tank of fluid.
Haha! Cool idea :)
Neat, clean execution. Back in 2002 I built a large sculpture of 12 organic wrought iron plants with CRTs on top of each one showing 6 different eyeball loops… all fed off of a bank of DVD players at that time, hah, and a stack of VCRs on the previous revision. The CRTs were on servo-controlled lazy susans so each of them literally looked randomly around the room. If you approached it in the center, a sensor would detect you and they’d all point straight at you and stare. Nice and creepy. https://www.youtube.com/watch?v=M8s-y_QrZ4Q
Nice job!
That’s awesome. I recall seeing similar installations at, I believe MOMA in SF back in late 90’s but one or more of those details is likely mis-remembered
Maybe Alan Rath? Bay area artist who had made lots of whimsical kinetic sculptures since the late 80’s… including a bunch of amazing CRT pieces with eyeballs and other various body parts.
CRTs are large and weighty, thus in order to have a sufficient safety factor the sturdiness of the design was greater than the nominal 20% (I believe 80% margin was used so a drop from 1 meter had to be with stood without spewing broken glass all over the place, it didn’t have to work just not be hazardous). The CRT front was made very durable due to implosion safety, that is if the front part of the CRT broke it could suck someones hand in, doing a LOT of damage (IE we’ll get sued if that happens). If someone takes it apart and breaks the neck the implosion is significantly less dangerous than the front going boom. Oh and the front of most CRTs were literally almost bullet proof, a friend showed me a TV that someone shot because their team messed up so many plays in the US Super bowl. The CRT had just left a divot in the screen but didn’t cause an implosion.
The real sad thing about the CRT is they had developed replacements for the ebeam already but no one used it because most development work in display tech was in LCDs. The demise of the CRT had little to do with what people assume, seriously people thinking that CRTs were “bad” technology is just ignorance, the real impetuous is the market share for development of new display devices had shifted to something portable and the profit for the laptop was a huge draw at that time. So research money went into LCD tech instead of CRT tech. Reality is far different than our personal delusions as I like to say it.
The money for LCD lines and available LCD display units made the shift much easier and thus swifter, lack of actual development funding for the static CRT practically didn’t exist. So that is part of the reason why the LCD ended up taking over from the CRT so quickly. It’s not as simple as that, just like Rome didn’t fall because one emperor was a complete idiot (there were a lot of idiots for emperors to be fair but Rome wouldn’t have fallen for that reason alone).
The resolution of this tiny crt is amazingly sharp. You can read the tiny text as it’s booting up and it’s not blurry at all. It’s like a Retina display!
Eye see what you did there…
Nice, but It would be interesting to see the schematics of the project, specially the schematics of the driver.