Stonehenge and Solitaire

My visit to Stonehenge in 1994

When Management Graphics adapted their film recording technology to support motion picture film formats, it was quickly adopted by movie studios to bring special effects from their computer memory images on to film.  There were some problems however, and one of the most serious was the difficulty in obtaining the full brightness range found in typical scenes, especially when they included lights—candle light, desk lamps, car headlights, streetlights.  Any light source, even a glimpse through a window to the bright outdoors, would cause a large flare in the final film frames, washing out detail in the scene.  Our customers complained, and we started down a path to research and solve the problem.

We understood what the fundamental issue was: halation, an effect caused by the glass faceplate of the cathode ray tube used for creating the image.  The bright spot on the phosphor screen was internally reflected at the glass surface which then illuminated the phosphor coating.  If phosphor were black, this would not be a problem, but phosphor coatings are white, as are most materials made of fine powder, and it resulted in this internal reflected light overexposing the film.  In the absence of a black phosphor, there were few other ways to mitigate the halation effect.

An example of halation on a photographic film plate.  The circular haloes and flare are apparent around the street lights in this 1910 image.

One of our customers was incorporating our film recorder into a full workstation system.  Quantel, a company in Newberry, England, had become successful in the early years of digital video and was looking for a way to expand its editing tool offerings into the motion picture market.  Quantel’s engineers understood the halation problem as well, but they didn’t want to rely on our figuring out a solution: they had an aggressive development schedule. 

Continue reading

An Oscar for Solitaire

I’m occasionally asked about the Academy Award that my colleagues at Management Graphics received. It was during the early days of computer-generated special effects in motion pictures. A product I contributed to, the Solitaire Image Recorder, was selected as a technology advance worthy of the Academy’s Technical Achievement Award.  These awards are delivered in a parallel ceremony to the one we are all familiar with.  It features celebrities of a different kind: nerds.

This is the story of how my friend Rick Keeney ended up on that award stage. It has been adapted from his personal account and is a bit technical, but don’t let those details detract from the overall story line.

Rick Keeney, with the Academy Award for Technical Achievement, 1992.

Invention and Innovation

In the formative days of digital photographic imaging, output back to film was produced using specialized, often hand-built, image recorders that were difficult to align, calibrate, and keep running consistently.  As one of the early companies in the business of building and selling graphics workstations, Management Graphics (MGI) recognized that the drawbacks of the available film recorders were limiting its workstation sales.  MGI kicked off a development effort to build a film recorder that would be a robust and easy-to-use product. 

Continue reading

The Burn-Hole Club

The coils that provide the magnetic force to move the electron beam

Cathode ray tubes are a remarkable technology that incorporate many seemingly magic principles of physics.  Thermionic emission causes electrons to “boil” off a cathode, high voltage electric fields accelerate and focus them, and magnetic fields steer them to the anode screen where they energize phosphor molecules, which then re-release that energy as visible light!

While developing the electronics to control the CRT and make all this magic happen, we often had to “bring up the spot”, showing the electron beam in one static location, where it could be examined visually and measured with various instruments. 

Continue reading

Cathode Rays

The 100th anniversary of the cathode ray tube.

This is the first of three posts describing a now-(nearly)-obsolete technology.

Thomas Edison nearly discovered them.  In his experiments with heated filaments in evacuated glass bulbs trying to find a suitable incandescent lamp, there were hints.  He noticed depositions of material on the walls of the glass tubes.  Many scientific discoveries are preceded not by the expression “Eureka”, but instead by the comment: “Hmm, that’s funny”.  If he had followed up on this odd result, he might have also invented the vacuum tube amplifier.

Continue reading

The Color of the Moon

I was 16 years old when Apollo-11 landed on the moon.  Color television had been invented but most TVs were still black and white.  I had seen a few color televisions on display and in other homes, but the color was usually awful, partly because the broadcasting signals had to be compatible with black and white sets. 

Continue reading

Career’s End

From my gun collection: an electron gun, extracted from a cathode ray tube

After years of fearing the consequences of corporate RIFs (“reduction in force”), aka layoffs, and having survived a dozen or more of them, I had finally reached the point where losing my job would have a lesser consequence.  I had built up my savings in anticipation of some future retirement and was now working for the sheer pleasure of it.  

Continue reading