Bolex 521

Filmprojector for 16mm films

Technical specifications

General
• Sound projector for magnetic recording and optical and magnetic reproduction of sound on 16mm film.
• Aluminium die-cast body, with plastic lid forming a case.
• Dimensions: 480 X 380 x 240 mm, excluding handle.
• Weight: approximately 40 lb.
• Connection to mains:
. a) Universal model with 4-position voltage selector: 118-127-220-240 V, 50/60 cycles;
b) European model 220 V150 cycles.

Capacity and threading
• For use with all standard spools up to 2000 ft.
• Automatic threading.

Mechanical system
• Film driven by electronically regulated low voltage electric motor.
• Projection speeds: 18 f.p.s., 24 f.p.s., from 12 to 26 f.p.s. (adjustable by potentiometer), "freezing" on a picture, single-frame projection.
• Electromagnetically controlled shutter with 2 or 3 blades.
• Rotating main switch with 6 settings.
• 4-digit frame counter (1 unit= 10 frames).
• Ventilation fan driven by separate motor.
• Screw-type feet for adjusting height and level.
• Framing adjustment by shifting claw spindle.

Lamp and lenses
• 24 V/250 W halogen lamp, with built-in dichroic mirror.
• Lens-mount, diam. 42.5 mm; focusing by milled knob.
• Three lenses to choose from: 50 mm f11.3, 70 mm f/l.6, 35-65 mm zoom f/l.6.

Sound system
• Fully transistorised amplifier, plugging into the projector in 3 separate units.
Power output 25 W with 2% harmonic distortion on 8 Q.
Response curve at direct amplification: 30 to ,20,000 cycles at ±3 dB.
• 3 W built-in loudspeaker (monitor).
• lOW loudspeakerfitted in the lid.
• Optical or magnetic sound playback volume control by independent potentiometer.
• Bass and treble tone control by two separate potentiometers operating during direct amplification and playback.
• Operating knob with 3 settings offering the following possibilities projection of silent films with magnetic head retracted, playback of sound recorded on the optical track, magnetic playback and recording.
• In all three positions it is possible to give a running commentary via the microphone or record-player inputs.
• Separate jack-type inputs for phono and microphone. Phono input from 50 mV to 2 V on 500 kQ. Microphone input from 0.2 mV to 8 mV on 5 kQ.
• Recording level adjustment by 2 separate potentiometers (microphone and phono). These 2 potentiometers also control the volume during
direct amplification (live commentary).
• Recording level threshold compression device.
• Double locking of recording eliminating any risk of accidental erasure.
• Checking of the recording level by VU-meter with needle, lit by a pilot lamp.
• Possibility of monitoring the recording through loudspeaker (at reduced power) or earphones .
• Potentiometer to variable erasure and gradual introduction of recording for superimpositions and sound dissolves.
• DIN 2-pin output socket for 8 Q loudspeaker.
• Combined DIN 5-pin output socket for 4 to 50 Q earphones and connection to an external amplifier (50 kQ).
• Recording/magnetic playback response curve: at 24 f.p.s., from 100 to 12,000 cycles at ±3 dB. Signal/background noise ratio: ~ 50 dB.
• Optical playback response curve: at 24 f.p.s., from 50 to 7,000 cycles at ± 3 dB. Signal/background noise ratio: ~ 60 dB.
• Wow rate: .:; 0.3%.
• Standard sound/picture separations: optical track, 26 frames; magnetic track, 28 frames. Accessories supplied with the projector
• 1 24 V/250 W halogen lamp, with built-in dichroic mirror
• 1 2,000 ft. reel with automatic attachment
• 1 power cord
• 1 record-player jack DIN 5-pin
• 1 microphone
• 1 brush

Optional accessories
• Earphones
• Wide-screen attachment (ratio of 2.66: 1) for use with 50 and 70 mm lenses.
• Wide-screen attachment mount.
• Accessory for remote control.