The human-eye adapts to lighting levels from which our ability to see depends. While simultaneously, this essential adaptability is making us ‘blind’ to see the actual brightness of artificial light sources. Exposure Value ZER0̷ is a research-based method and photographic exploration to unravel and map the imperceptible brightness in urban areas. The work exposes the most heavy illuminated places in Paris and London and is reflecting on the practice of (photographic) light metering and the notion of the 'over-exposed' image. Far from simply producing a clear-eyed copy of reality, these images are something closer to a qualitative expression of light— discovered rather than created.