This gentle craft appears at a glance to be an easy feat, and yet is so utterly difficult. Subjects cannot be manufactured, the light cannot be forced, and patience is not an option to be discarded. Darkness is the canvas. Slowly and carefully the light is allowed to bleed onto the film.
David has a distinctive style, one he calls 'slow photography'. His images frequently have an ethereal and painterly quality, a result of slow film and long shutter speeds ranging from seconds to hours.
It is known that the human brain does not process moments in time that are much faster than 1/10 of a second, otherwise registering these moments as movement. Slow photography is not about trying to capture moments that are possibly too brief for us to see. It is about layering a series of moments together to create an otherwise un-created and un-recognized image. It is the layering of time onto film. "
Source: The epson international photographic pano awards