Undersight: Morse Code App for Cassils' Nuit Blanche

Undersight
Decoding Light in Real Time
Cassils in a reflective work suit pulls a lever beside a light beam rising into the night sky
Cassils seen from behind on a platform at dusk, with light beams rising above a blue digital timer
Cassils holds a lever beside a bright light beam and a brick smokestack, in black and white

We built the app for Cassils' twelve-hour Nuit Blanche performance, decoding Morse code light beams in real time.

Overview

Undersight was a twelve-hour performance by artist Cassils that used powerful light beams and Morse code to transmit words into the night sky. Created with lighting artist Christopher Kuhl and curated by Renata Azevedo Moreira for Toronto's Nuit Blanche, the performance broadcast words being quietly removed from US government documents and websites: diversity, equity, climate change, gender, and other terms now flagged by federal agencies. The work was about the erasure of language and the communities it represents.

What We Built

Heroic served as Digital Director and Producing Partner. We built the Undersight app for iOS and Android: a free tool that used a phone's camera to detect Morse code light pulses and translate them on screen in real time. Anyone across the city could point their phone at the light beams and read the messages as they appeared. We developed the camera detection algorithms and the full translation interface.

Coverage

The performance was covered by Artforum and CBC, which called it one of the standout works of Nuit Blanche Toronto 2025.

Cassils from behind, hair lit at the edges, facing two blue light beams filled with dust specks

PRESS

Cassils
Artforum
Still deciding what to see at Toronto's Nuit Blanche? Start with these 9 projects
CBC
Handwritten planning sketch showing a figure labeled Cassils on a platform beside a louvered light shutter
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Phone screen showing the Undersight artist statement over a starry sky and a light beam from a platform
Cassils in profile in a reflective work suit, arms extended into darkness, in black and white
Bright light beams rising from the top edge of a black box at night, in black and white
Cassils seen from below, gripping a bar with gloved hands under a light beam in the night sky
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App open
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