Monochrome CRT And Liquid Crystal Shutter Team Up For Color Video

If you were tasked with designing a color video monitor, it’s pretty clear how you’d go about it. But what if you’d been asked to do so 20 years ago? Would it have been a cut and dried from an engineering standpoint? Apparently not, as this hybrid LCD-CRT video monitor demonstrates.

We’d honestly never heard of this particular design, dubbed “LCCS”, or liquid crystal color shutter, until [Technology Connections]’ partial teardown of the JVC monitor and explanation of its operation. The idea is simple and hearkens back to the earliest days of color TV in the United States, when broadcasters were busy trying to bring color to a monochrome world in a way that would maximize profits. One scheme involved rotating a color wheel in front of the black-and-white CRT and synchronizing the two, which is essentially what’s happening in the LCCS system. The liquid crystal panel cycles between red, blue, and green tints in time with the CRT’s images behind it, creating a full-color picture. “But wait!” you cry. “Surely there were small color CRTs back in the year 2000!” Of course there were, but they kind of sucked. Just look at the comparison of a color CRT and the LCCS in the video below and you’ll see why this system carved out a niche in the pro video market, especially for video assist monitors in the days before digital cinematography. A similar system was used by Tektronix for color oscilloscopes, too.

As usual, [Technology Connections] has managed to dig up an interesting bit of the technological fossil record and present it in a fascinating way. From video on vinyl to 1980s copy protection to the innards of a toaster, we enjoy the look under the hood of forgotten tech.

Continue reading “Monochrome CRT And Liquid Crystal Shutter Team Up For Color Video”

Upgrading A MIDI Controller With An FPGA

While the “M” in MIDI stands for “musical”, it’s possible to use this standard for other things as well. [s-ol] has been working on a VJ setup (mixing video instead of music) using various potentiometer-based hardware and MIDI to interface everything together. After becoming frustrated with drift in the potentiometers, he set out to outfit the entire rig with custom-built encoders.

[s-ol] designed the rotary-encoder based boards around an FPGA. It monitors the encoder for changes, controls eight RGB LEDs per knob, and even does capacitive touch sensing on the aluminum knob itself. The FPGA communicates via SPI with an Arduino master controller which communicates to a PC using a serial interface. This is [s-ol]’s first time diving into an FPGA project and it looks like he hit it out of the park!.

Even if you’re not mixing video or music, these encoders might be useful to any project where a standard analog potentiometer isn’t accurate or precise enough, or if you just need something that can dial into a specific value quickly. Potentiometers fall short in many different ways, but if you don’t want to replace them you might modify potentiometers to suit your purposes.

Continue reading “Upgrading A MIDI Controller With An FPGA”

Control Lighting Effects Without Programming

Working in a theater or night club often requires a specialized set of technical skills that you might not instantly think about. Sure, the audio system needs to be set up and managed but the lighting system is often actively managed as well. For simple setups, this is usually not too difficult to learn. With more complicated systems you will need to get elbow-deep into some software. With [trackme518]’s latest tool, though, you will only need to be able to edit video.

Sure, this sounds like just trading one piece of software for another, but it’s more likely that professionals working in lighting will already know how to edit video rather than know programming or complicated proprietary lighting software. All you have to do to control a set of lights is to create a video, or use an existing one, and the lighting system will mimic the video on its own. If you do know programming, though, it’s written in Processing Java so changes aren’t too difficult to make.

The software (available on the project’s GitHub page) will also work outside of a professional environment, as well. It’s set up to work with DMX systems as well as LED strips so you could use it to run a large LED display board using only an input video as control. You could even use it to run the display on your guitar.

Photo courtesy of Rob Sinclair (Gribiche) [CC BY-SA 2.0 (]

An All-In-One Conference Video Streaming Box

When running a hacker camp or other event, one of the many challenges faced by the organisers concerns the production and distribution of event videos. As the talks are recorded they must be put online, and with a load of talks to be processed it quickly becomes impractical to upload them one by one through a web interface such as that provided by YouTube. At the BornHack 2019 hacker camp in Denmark they were using a particularly well-integrated unit to do the video uploading in real time, and its creator [Mikkel Mikjær Christensen]  was good enough to share the video we’ve put below the break, a talk he gave about it at The Camp 2017, a Danish open source software camp.

It takes the viewer through the evolution over several years, from simple camcorders with integrated microphones and post-event processing, through a first-generation system with a laptop and rack-mount monitors, and into a final system in a rugged portable case with a significantly powerful laptop running OBS with a hardware MPEG encoder. Careful choice of power supplies and the use of good quality wireless microphones now give instantaneous video streaming to events such as BornHack without the need for extensive infrastructure.

If you were wondering where you might have heard that name before, [Mikkel] is the [Mike] from the Retrocomputing with Mike YouTube channel. It’s being honest to say that more of our conversation was about retrocomputers than the video box.

Continue reading “An All-In-One Conference Video Streaming Box”

Building DIY Acoustic Panels To Cut Down On Echoes

Plenty of hackers and makers are passionate about content creation. In the dog-eat-ice-bucket-challenge world of online video, production value is everything. If you want to improve your audio quality then cutting down on echoes is a must, and these acoustic panels will help you to do just that. 

The build starts with aluminium L-channel, affixed together into an equilateral triangle with the help of some 3D printed brackets. Two of the triangular frames are then fitted together via a series of hexagonal standoffs. Foam or housing insulation is then added to act as the primary sound absorbing material. To give an attractive finish, the panels are covered in fabric. The panels are then placed on to drywall using nails glued into the standoffs.

While the panels are likely more expensive to build than off-the-shelf foam alternatives, they have an attractive look which is key in video studio environments. If you’re wondering where to position them for the best results, there’s a simple and easy approach to figure it out. Video after the break.

Continue reading “Building DIY Acoustic Panels To Cut Down On Echoes”

Art Project Analyzes Every Public Recording Of Facebook’s CEO Since 2004

[Benjamin Grosser] had a simple question: “What does Mark Zuckerberg think about?” The resulting art project is named ORDER OF MAGNITUDE and to create it he researched archives of every public utterance the founder and CEO of the world’s largest social media network has made, going as far back as 2004.

The end product is a nearly fifty-minute film consisting entirely of cuts centered around what [Benjamin] says are three of the Facebook CEO’s most favored and often-used terms:

  • The word “more”
  • The word “grow”
  • Metrics such as “ninety-nine percent”, “two million”, and terms of that nature.

The idea is that the resulting video provides insight into what Mark Zuckerberg thinks about, has focused on, and how that has (or has not) changed between 2004 and now.  How well does ORDER OF MAGNITUDE do that? Watch the video below, and judge for yourself.

Continue reading “Art Project Analyzes Every Public Recording Of Facebook’s CEO Since 2004”

Vintage Monoscope Tubes Generate Classic TV Test Patterns Once Again

Night creatures and insomniacs of a bygone era may fondly recall a TV test pattern appearing once [Jack Parr] or [Steve Allen] had had their say and the local TV station’s regular broadcast day had concluded. It was affectionately known as the Indian Head test pattern, for the stylized Native American, resplendent in a feathered headdress, that featured prominently in the graphic.

Unknown to most viewers was exactly how that test pattern and others like it were generated. But thanks to [Rich “The Lab Guy” Diehl] and his monoscope restoration project, we can all share in the retro details. It turns out that while some test patterns were merely a studio camera trained on a printed card, most were generated by a special tube called a monoscope. It functioned in basically the same manner as a studio camera, but rather than scanning the incident light of a scene with an electron beam, the image was permanently etched into a thin aluminum plate. [Rich] laid hands on two vintage monoscope tubes, one containing the Indian Head test pattern, and set about building a device to use them. “The Chief” can hold either tube in a Faraday cage of thin, flexible PCB material and 3D-printed parts, with supporting electronics like the power supply and video amplifiers in an aluminum chassis below.

It’s a nice piece of work and a great lesson in how it used to be done, and the lithophane of the Indian head is a nice touch. Hats off to [The Lab Guy] for build quality and great documentation, including a detailed video series that starts with the video below. If you need a little more background on how video came to be, [Philo Farnsworth]’s story is a good place to start.

Continue reading “Vintage Monoscope Tubes Generate Classic TV Test Patterns Once Again”