I’m not sure if they are even used anymore, but back in the day engineers used spark cameras to capture very brief timescale events.
For a camera with a shutter, the shutter is in T (time) mode, in a dark room. For view cameras, the lite-tite dark slide on film holders is pulled out. Sparks in air generally do not give a uniform spectral (white light) distribution. Electronically triggered flash lamps were a major upgrade. Triggering a spark discharge in air was usually done by manually discharging a capacitor bank, so synchronizing with a shutter was difficult.When you call it a "spark camera," what exactly do you mean? Do you mean a conventionally shuttered camera with a fast flash which exposes the object while the shutter is open?