NOTE: This article is dynamic in that it will change over time as new or different information is found.
First published 14NOV06 - current revision 20NOV2006

At some point in 1920, 25 year-old Laurens Hammond of Detroit had an idea for a stereoscopic motion picture system.

It would seem the best possible reference to read before going any further can be currently found at:

The Hammond Story

The patent for the basic system was filed by Laurens Hammond (1895-1973) on 2MAR1921, so one can assume the actual development (tests) preceded this date. So far, I have found three patents, though there should be four.

His first demonstration was with slide projectors (still images) which impressed enough to obtain apparently several hundreds of thousands of dollars.

They needed to locate a theater that they could literally take over for (hopefully) an extended period of time.

That theater was the 964 seat Selwyn, 229 West 42nd Street, NYC. Opened only four years earlier, the Selwyn was a legitimate house up to that time, showing films only on occasion. It didn’t become a move house until 1934. During a major restoration JAN1998, the Selwyn collapsed, and The American Airlines Theater now occupies the location.

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The Selwyn Theatre in the 1920's and the interior just before demolition in 1998.


The first written record of this momentous technology appears to be in the New York Times (NYT), 22OCT1922.

Accounts at the time also mentioned a William F. Cassidy as an ill-defined associate, though Hammond’s not mentioning him kind of diminishes his import.

By that time Hammond and associates had shot a feature film, M.A.R.S. Hammond said he wrote the screenplay, though IMDB lists Lewis Allen Browne. It was made by, at or with ‘Tilford Cinema Studios.’ And by the time the show opened, they also had produced what I estimate was a one reel prologue.

M.A.R.S. is the world's second 3D feature film.

At some point Hammond stumbled onto the stereoscopic shadowgraph concept. I have not found any documentation about how this came about.

Teleview was not an original idea, which Hammond even admits in his patents, but he made it work where previous attempts didn’t (such as Jenkins, 1897).

In the theater, two normal projectors were linked with sync motors, so they ran in absolute sync. They were Power’s projectors, the current model of the time being the six-B. Very simple machine for modification.

Hammond’s genius was in the electrical conception and execution.

He had an electric motor turn an AC generator so his system was isolated from the poor quality city power.
This allowed him to precisely control the AC frequency, which in the U.S. is 60 cycles (hertz, Hz). This was a key aspect of his idea.

The projectors were driven by this regulated AC, via their own sync motors. If the AC frequency was raised, the projectors would run faster. Very accurate control.

The left film was in the left projector and right film in the right.

The projectors were in frame sync, but the shutters were out of phase sync (look carefully at the patent diagram).

Attached to each and every seat in the theater were the viewing devices. They were stored neatly in front of the seat arm. One sat down and grasped the viewer and pulled up. It was mounted on a flexible neck, similar to some adjustable "gooseneck" desk lamps. You twisted it around and centered it in front of your face, kind of like a mask floating just in front of your face.

This viewing device is the jewel in the crown. Based on photos and the patents, Hammond’s viewer is a great design.


In spite of the immagination of the various artists, the viewing device would have been no farther than maybe 4" from one's face in order for both eyes to see the entire screen.

In the round enclosure was a very small (1 /34" diameter), 12 volt AC, 3-pole sync motor. I believe this motor went on to become part of his Hammond organ a few years later.

Attached to the motor was a miniature version of the projector shutter.

The viewer had a window permitting both of your eyes to see through the shutter to the screen. There was glass in the windows to prevent you from chopping your nose off and insulate the sound of the device.

The AC system powered this device, and the sync motors automatically would go into “phase” so all the viewers in the theater would be exactly the same.

This was pretty good stuff for 1922.

But Hammond had to work out the flicker problem. Normal film speed at the time was 16 frames per second. Yes, we know this varied a lot, especially to faster speed such as 20 fps. But 16 is what he shot his film at and specifies in his patents.

A shutter-based system such as this is sequential. That is, our eyes get the left and right images one eye at a time, first the left, then the right. This is a frame sequential method. We’ll get into problems with this method later.

At 16 fps, the L-R sequence would cause highly irritating flicker. But Hammond chopped up each frame into three flashes, versus one or even two. The sequence was: 1L-1R-1L-1R-1L-1-R  2L-2R-2L-2R-2L-2R and so on. Three alternate flashes per eye on the screen.

This increased the flicker frequency to invisibility.

As you would look through the device, your left eye would see only the left image, with your right eye being blocked. Then the shutter in the device blocks the left eye, unveiling the right eye. All in sync with the left and right images being flashed on the screen.

Even through today’s eyes, this system would look good. Top notch except for the time delay between the left and right views. The average person wouldn’t notice, but it would be bothersome for fast subject motion. All sequential methods have this drawback.

The grand premiere was on 27DEC1922.

Opening day ad. Wasn't much.


Cover of the "instruction manual" handed out as one entered the theater.


What is amazing historically is that the first 3D film exhibited to a paying, theatrical audience was premiered just four days earlier: William van Doren KELLEY’S PLASTICON MOVIES – MOVIES OF THE FUTURE, a one reel, anaglyph short, shown at the Rivoli Theatre not even 8 blocks away from the Selwyn. Anybody got a time machine?

According to the reviews, the show started with a prologue composed of still 3D artwork and photos, along with motion footage of the Canadian Rockies and scenes of Navajo and Hopi Indians! I believe this footage was probably not more than one “reel” and likely produced before the feature to work bugs out of the camera. There is no significant information about the camera used, sadly.

While the projectors were being threaded up with the feature, one of the highlights was the 3D shadowgraph. Hammond filed for a patent on this concept on 23JAN1923.

It was a simple idea. Move the normal projection screen out of the way (the projectors were not used for this act), and replace it with a translucent type. Imagine a simple sheet. It is possible they had a screen fabric that could be used both ways.

At the back wall of the stage (about 30’ deep) were two, high-intensity arc lamps facing the screen. They were spaced side-by-side perhaps 3” or so apart, and had shutters exactly like on the projectors and the viewing units, to alternately block one light, then the other.

When a performer stood between the lights and the screen, the audience saw a silhouette. And because of the two lights and shutters, when viewed through the Teleview viewer, the silhouette was stereoscopic and would appear to float off the screen into the auditorium.

As this was a live act, the audience was even more amazed than with the films. This was an extremely successful part of the program, and I’ll cover 3D shadowgraphs in more detail in a separate chapter.

Lastly, the “fantasy-comedy” feature M.A.R.S. was presented. From what I have gathered, this was the least-liked aspect of Teleview.

The press…was quite impressed by the Teleview concept, but after only 24 days, 20JAN23, the show closed. It was announced in the New York Times that a new show would be seen in March, at the same theater.

Teleview was never heard from again.

In light of Hammond’s crying in his pillow all night long, this shouldn’t surprise. Technically it was a wonder. Commercially?

The 3D shadowgraph concept was seen around the world in a few places over a number of years, though not to Hammond's benefit.

M.A.R.S. was ultimately retitled RADIO MANIA (or RADIO-MANIA), and seen 2-D nationally in '23-'24. Interestingly, the distributor was W. W. Hodkinson, the founder of Paramount Pictures distribution company which Zukor & Lasky eventually took over forming Paramount Pictures Corp. Hodkinson had a very interesting career:


One review (JUL24): "Grant Mitchell in 'RADIO-MANIA.' This star will be seen for the first time in pictures in this Hodkinson production in six reels. Mr. Mitchell has temporarily left the legitimate stage, where he has in the past years established himself as one of the great comedians in the world. MARGARET IRVING, the leading lady, was selected as one of the twelve most beautiful women in America. You will gaze in amazement at the unusual scenes presented. This picture is something out of the ordinary—a tinge of romance, soaked in comedy and draped with settings and costumes that make it a most unusual picture. Be sure to see it."

The following images are from the film, giving a clue as to the "fantasy" aspect (courtesy of Jack Theakston).



The first image gives a tantalizing clue that the sets were 3D-friendly. Third image might have influenced Jack Pierce for the look of the BRIDE OF FRANKENSTEIN.

We have no idea of the disposition of the 6-700 viewing devices, plus parts. Did Hammond just junk them? That many units would take up some storage space so it’s not likely they linger, ignored to this date.

What surprises me is that Hammond didn’t himself keep one. Just ONE, from one of his first of 110 patents. But it might be that he had less-than-happy memories of that time or whatever. We'll likely never know.

And one major mystery remains: exactly like the one from THE POWER OF LOVE, how did Hammond show a feature (assuming "6 reels") when both projectors were tied up? Reel changes every 15-16 minutes? Not likely. It is possible Hammond installed 4 projectors, and is the most likely solution. Just a theory.

Hammond wasn’t a 3D enthusiast more than an inventor who had an idea. His methods are still excellent. But people didn’t want a “device” hanging in front of their faces to watch a “movie.” To see a novelty, yes. A movie, no.


Thanks to Jeff Joseph and Jack Theakston.


3D Films can be viewed on computers using Technologies like Nvidia GeForce 3D Vision which is no longer supported, you can get used gear from sites like ebay, and drivers from 3D Vision Nvidia Driver