How to Use
This is a recreation of Ben Laposky's oscilloscope art setup from the 1950s. He used a DuMont 304-A cathode ray oscilloscope with external signal generators to create the first electronic art — his "Oscillons." Two signals feed the horizontal (X) and vertical (Y) deflection plates, a third (Z) modulates beam brightness, and a simulated camera photographs the result.
Quick Start
Press 1 through 5 to load a preset. Watch the green trace on the screen. Press Space to take a photograph. The resulting image downloads as a PNG in gelatin silver print tones, just like Laposky's original prints.
The Presets
1 Oscillon — AM Petals — 2:1 figure-8 with amplitude modulation creating breathing petals. Z-axis blanking, full focus, 1/20s flash exposure with film bloom.
2 Waterfall — Ultra-slow harmonic drift. 5s exposure.
3 Nautilus — Detuned 5:3 ratio with harmonics. Complex spiraling form, 1.2s.
4 Channel Z — Beam blanking demo. A slow circle with Z modulation creating bright/dark segments. Watch the beam to understand how Channel Z works.
5 Flash — High-speed 1/20s capture. 6,000 Hz signals at Laposky's actual exposure speed with Z-axis dimming, max intensity. Press Space — the photograph is instant.
The Knobs
Grab and turn in a circular motion, just like real oscilloscope knobs. Hold Shift while turning for fine control. You can also click the green number below any knob or slider to type a value directly.
Channel X & Y (Left Panel)
Frequency controls how fast the beam oscillates on that axis. The ratio between X and Y determines the basic shape: 1:1 makes a circle, 2:1 makes a figure-8, 3:2 makes a pretzel. The knobs are logarithmic — fine control at low values, full range up to 30,000 Hz (matching Laposky's DuMont 304-A).
Phase shifts the timing between the two signals. This tilts and opens the figure. Small changes create big visual differences.
Amplitude controls how far the beam swings on that axis. Asymmetric amplitudes (X different from Y) stretch the figure.
Waveform buttons change the signal shape. Sine makes smooth curves. Triangle makes angular peaks. Sawtooth and square create sharp, geometric patterns. Laposky used all four.
Channel Z (Left Panel)
A third signal that modulates beam brightness in real time. Parts of the trace become bright while others go dim or disappear entirely. This was a standard input on Laposky's DuMont 304-A and is key to the dramatic brightness variation in his photographs. Set Depth above 0 to activate it. Try matching the Z frequency to your X or Y frequency for synchronized patterns.
The Laposky Trick
Laposky's most famous technique: slightly detune the frequencies from an exact ratio. Instead of exactly 2:1, use something like 100:50.1. The figure never quite closes and slowly precesses. A long exposure captures many slightly-rotated copies, creating the characteristic fan of traces you see in his Oscillons.
Higher frequencies (100+ Hz) give smoother traces in shorter exposures. Lower frequencies (1-5 Hz) let you watch the beam trace in real time. Laposky's actual exposures were 1/20s to 1/2s at high frequencies.
Beam Controls (Right Panel)
Intensity is the beam brightness — Laposky's brightness knob. This controls both the live display and the exposure brightness (brighter beam = brighter photograph, just like the real thing). Focus controls the beam spot sharpness — 0 is a tight pinpoint, 1 is a soft diffuse glow. Laposky controlled focus on his oscilloscope to vary trace thickness.
Exposure (Right Panel)
Set the duration (0.05s to 60s) and click Expose or press Space. Space always fires instantly. Clicking the Expose button uses the countdown timer if it's toggled on (the button next to Expose). When the shutter closes, a PNG downloads in gelatin silver print tones. Film Bloom controls how soft the exported photograph looks — simulating light diffusion in Laposky's camera lens and film emulsion. Higher values create the dreamy, soft quality of his original prints. Turn up Intensity for brighter photographs.
Bottom Bar
LFO is a slow invisible wave that modulates any parameter over time. Set a target (Freq, Phase, Amp, or Mix), a rate, and a depth. This makes patterns breathe and evolve during exposures.
Harmonics blends a second oscillator into each channel. Two modes: Additive mixes the signals together (adding complexity to the shape). Modulate (amplitude modulation) uses the harmonic to control the primary signal's volume — the figure breathes, swells, and pulses. This is how Laposky created figures with petals that widen and narrow along the curve. Even small Mix values (0.1-0.3) create dramatic effects in Modulate mode.
Mic feeds your microphone into the beam. Laposky didn't have this one — it's the one non-historical feature.
Save & Load Settings
Click Save to File to export all current knob positions as a JSON file. Click Load File to import a previously saved file. Build a library of discoveries, share settings with others, or back up before experimenting. Something Laposky could never do — he lost every setting the moment he changed a knob.
MIDI Controller
Connect a MIDI controller (like a Korg nanoKONTROL) for hands-on control of multiple parameters at once — the closest experience to Laposky's actual setup. Click the MIDI button to connect, then click it again to enter mapping mode. Click any knob or slider on screen, then turn a physical MIDI knob to pair them. Mappings persist between sessions.
Keyboard Shortcuts
1-5 Load presets Space Start/stop exposure Shift+drag Fine knob control
