Magazine article American Cinematographer


Magazine article American Cinematographer


Article excerpt

A sophisticated new projector that features many professional options and allows instrumental and vocal playback with a high degree of sound fidelity

The Bolex 521, a new 16mm sound projector, which can also be used for viewing silent films, has been introduced by the Photo Products Division of Ehrenreich Photo-Optical Industries, Inc.

The projector is designed for use m lecture halls, classrooms, laboratories, studios, workshops and small theatres.

Highest Quality Audio Reproduction

Films with sound carried either magnetically or optically may be played back during screening. Additional sound may be added magnetically by direct sound mixing or by superimposition. Sound dissolves are also possible. And, finally, sound can be magnetically added to silent films.

To prevent sound saturation, a threshold compression device is activated as soon as critical recording levels are reached. Modulation peaks are instantly reduced. A lighted VU-meter (sound level gauge) and a built-in 3-watt speaker, or use of earphones, permits monitoring or editing without distracting others.

The amplifier has an output of 25 watts, which allows instrumental and vocal playback to be heard with a high degree of sound fidelity. Orchestral or even operatic vocal resources can be reproduced faithfully.

Separate microphone or record-player jacks enable simultaneous commentary or musical mixing for multiple sound input. Double locking devices prevent accidental erasure of pre-recorded sound materials. There are controls for treble, bass, volume, sound fade and superimposition.

Standard sound/picture separation for optical track is 26 frames; magnetic sound/picture separation is 28 frames. Signal background noise is extremely low and the "wow" rate is ±0.3 ½-virtually indiscernable.

A single safety switch controls choice of magnetic, optical sound or silent film projection. This switch also activates a mechanism which retracts the magnetic recording head during silent or optical film projection and, thereby, prolongs its usefulness.

Full Feature Film Operation

The Bolex 521 accepts all standard film spools up to 2,000 feet (about one hour) for comfortable, interruption-free, feature film viewing. Automatic, foolproof film threading allows rapid and easy use. No special training is necessary.

A separate motor drives the ventilation fan for silent and efficient cooling; electronically controlled, the motor assures smooth film transport and prevents flickering or uneven image. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed


An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.