There is no lamp. Nothing flashes. The picture is simply redrawn at the sampling instants and holds still between them — which does to your eye what a real strobe does, on a steady screen.
So the strobe slider is a sampling rate. It does nothing until it is near the rate the instrument repeats at.
Pinch, drag to pan, or the Zoom buttons. Tap the middle one to return the instrument to its resting scale. The wheel works on a desktop.
There are two kinds in that tray, and this is the part worth reading.
To hear the audio chains at the same time, open Sound and turn the Tone on. Set an audio chain and a light chain to the same ratio and the notch sweep and the pattern surge run in step.
Tone generates a note at the strobe rate times an octave multiplier, so a 4 Hz strobe can be heard at 512 Hz. Pulsed gates it open at each sampling instant, so you hear the rhythm rather than a drone.
Mic, line, or a media file. Pitch folds the detected note down into strobe range; Beat follows onsets; Level drives the speed. Nothing is recorded or sent anywhere — the signal is analysed here and discarded.
Vector redraws everything as line work with a phosphor beam. Rig cycles Direct, Mirror, Twin and Pyramid for Pepper's Ghost; Calibrate is the polarisation test; Ghost hides every pixel that is not the figure. Exports go out as SVG, a PiTrex .c reel, or JSON.
Space stops the strobe · F full screen · H shows and hides the panel · Escape closes a tray · ↑ ↓ nudge the strobe · D docks a dragged panel.
Tone generator — locked to the light pulse
Octave multiplier — strobe Hz × 2ⁿ
Volume
Pulsed gates the tone open at each flash instant, so you hear the strobe rate as rhythm. Continuous holds the pitch. At ×1 the oscillator runs at the strobe rate itself — subsonic, but square and saw make it audible as clicks.
Sound in
What the sound drives
Mic and line are both audio inputs — pick the exact device from the list once permission is granted. Nothing is recorded or sent anywhere; the signal is analysed in the page and discarded.
Zoetrope reel — 24 cells, multiplexed
The drum carries one strip of 24 cells holding six interleaved sequences. Which one you see depends on how many cells the light skips between flashes — so the animation changes as you move either slider. Lock at the fundamental for the first sequence, halve the strobe for the second, and so on.
Manual override
Two phaser chains — all-pass banks swept by the light
Chain A
Chain B
The rate buttons lock each sweep to the strobe: ×1 walks the notches once per flash, ×1/4 takes four flashes to get round, free runs at its own pace. Two chains at different ratios beat against each other the same way the light beats against the motion. Series stacks them, parallel sums them, stereo puts one in each ear.
Light chains — the sampler, swept
Depth is how far either side of your strobe setting the sweep pulls, as a percentage. A few percent rocks the pattern gently; twenty sends it surging forward and back through lock. Ratios lock each sweep to the strobe the same way the audio chains do — two that do not divide evenly never repeat.
Vector output — line work only, on true black
The room — QuadStage bus
Export
Ghost hides every pixel that is not the figure — anything not #000000 hangs in the glass as a visible pane. A single pane reverses left and right, so use Mirror; Twin flips each half for its own viewer; Pyramid quarters it. Calibrate first: rotating the panel 90° is worth about ten times the brightness and costs nothing.
Sampled mode — a flash without the flash. The picture updates only at the strobe instants, so motion freezes on a steady screen.