Comments on Dead Media Working Note 47.3
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Date: Wed, 17 May 2000 09:19:51 EDT

to: Didier Volkaert c/o Dead Media List:

Dear Mr. Volkaert,

I was very interested to hear about your non-electronic media work, as I basically agree with you that electronic images can be considered "virtual" images.

I thought you might be interested to know of a device that demonstrates this in an unusual way. I believe I posted it to the list several years ago, but I'm not sure it made it to the master list, as it is really a test instrument, rather than an information medium in the usual sense. This device is an "oscillograph", built by Westinghouse in, I believe, 1927. The oscillograph is an oscilloscope-like device that does not use a cathode-ray tube or electronic components, but operates optically-mechanically and electrically (for illumination, motor, and vibration). It shines a projection bulb, which picks up a "cross-hairs" targeting image, through 7 small prisms to adjustable mirrors mounted on top of 7 vibrating galvanometers, each of which is connected by the user to input signals of the respective frequencies to be studied, via pairs of binding posts on the sides of the machines.

The mirrors on top of each galvanometer reflect the signal 10 or 15 upward onto a moto-driven shaft rotating in the horizontal plane, whose surface is formed of long strips of optical-quality mirror, and which is driven by a Bodine motor. These rotating strip-mirrors project the vibrating images from the galvanometers onto either a quarter-cylinder isinglass rear-view screen, for full viewing, or onto a window with graticule, position markers, etc. for measurement (you can also remove the isinglass and project the images onto the ceiling of a darkened room). The motor is equipped with a mechanical governor with which you adjust the speed of the motor in order to freeze the image cast by the vibrating galvanometers, and thus view the waveform.

What I thought might be of particular interest to you is the great beauty of the "non-virtual" waveform images produced by this device, as compared to the images produced by a conventional CRT oscilloscope.

I found one of these machines in 1966, when I was doing some multimedia production, and often thought of using it as a model for a public exhibition piece of some sort. If you, or anyone else on the list, should have any interest in building a similar device for this purpose I'd be happy to assist by sending specifications from this one. It would probably actually be easier to build a device like this on a larger scale than at the laboratory bench-instrument size of the Westinghouse machine.

15 years ago, through my multimedia and audio work, I became involved, as a consultant to several organizations, in the development of improved computer monitors, and in encouraging the use of flat-panel (LCD) displays. I would be interested in knowing whether you find that such displays -- particularly in conjunction with the "high-definition" video format (1024 vertical lines) -- at all diminish the distinction between "real" (i.e., optical) and "virtual" (electronic) visual media.

Michael Mason micmason@aol.com




Date: Wed, 17 May 2000 09:19:51 EDT

to: Didier Volkaert c/o Dead Media List:

Dear Mr. Volkaert,

I was very interested to hear about your non-electronic media work, as I basically agree with you that electronic images can be considered "virtual" images.

I thought you might be interested to know of a device that demonstrates this in an unusual way. I believe I posted it to the list several years ago, but I'm not sure it made it to the master list, as it is really a test instrument, rather than an information medium in the usual sense. This device is an "oscillograph", built by Westinghouse in, I believe, 1927. The oscillograph is an oscilloscope-like device that does not use a cathode-ray tube or electronic components, but operates optically-mechanically and electrically (for illumination, motor, and vibration). It shines a projection bulb, which picks up a "cross-hairs" targeting image, through 7 small prisms to adjustable mirrors mounted on top of 7 vibrating galvanometers, each of which is connected by the user to input signals of the respective frequencies to be studied, via pairs of binding posts on the sides of the machines.

The mirrors on top of each galvanometer reflect the signal 10 or 15 upward onto a moto-driven shaft rotating in the horizontal plane, whose surface is formed of long strips of optical-quality mirror, and which is driven by a Bodine motor. These rotating strip-mirrors project the vibrating images from the galvanometers onto either a quarter-cylinder isinglass rear-view screen, for full viewing, or onto a window with graticule, position markers, etc. for measurement (you can also remove the isinglass and project the images onto the ceiling of a darkened room). The motor is equipped with a mechanical governor with which you adjust the speed of the motor in order to freeze the image cast by the vibrating galvanometers, and thus view the waveform.

What I thought might be of particular interest to you is the great beauty of the "non-virtual" waveform images produced by this device, as compared to the images produced by a conventional CRT oscilloscope.

I found one of these machines in 1966, when I was doing some multimedia production, and often thought of using it as a model for a public exhibition piece of some sort. If you, or anyone else on the list, should have any interest in building a similar device for this purpose I'd be happy to assist by sending specifications from this one. It would probably actually be easier to build a device like this on a larger scale than at the laboratory bench-instrument size of the Westinghouse machine.

15 years ago, through my multimedia and audio work, I became involved, as a consultant to several organizations, in the development of improved computer monitors, and in encouraging the use of flat-panel (LCD) displays. I would be interested in knowing whether you find that such displays -- particularly in conjunction with the "high-definition" video format (1024 vertical lines) -- at all diminish the distinction between "real" (i.e., optical) and "virtual" (electronic) visual media.

Michael Mason micmason@aol.com