Nothing in this corridor is lit except a lamp on a tripod, and I put it there.
The camera is almost against the flank of the nearest cabinet, so that the punching runs away in extreme perspective. Two staggered columns of rectangular slots go down the panel, and around them a field of round perforations in a diagonal pattern, and the surface is chalked and scuffed and rubbed pale at the height where a trolley has gone past it a thousand times. A steel bail handle sticks out at waist height. Further along, an open frame with cabling laced up the uprights. Then the corridor, the raised floor with a grille panel set into it, the scribed arc on a tile where a lifting tool has swept, and at the far end, maybe fifteen metres away, a work light on a tripod.
Thirty seconds at f/11. The only reason the flank is legible at all is that I stood still for half a minute while the sensor collected whatever came off that one lamp at the far end.
Everybody carries a picture of a machine room in their head, and in the picture it is blue and full of small lights and there are ranks of them going off into a dark that is somehow luminous. That image is real, and it was made by somebody with permission, a wide lens, a tripod, and a thirty second exposure. What the eye actually has in a room like that is very little. The lights are pinpoints, they are on the front faces only, and if you are working you are usually looking at a flank or a rear, and you are holding a torch in your teeth.
So this picture is the one I most wanted to make and the one I was least sure would survive. It has no subject in the ordinary sense. It is a wall of punched steel that describes itself for a metre and then gives up, and a corridor that goes to black, and a lamp at the end that is not lighting the room, only announcing where the electrician left it.
The rooms these are modelled on run at a light level chosen for machines that do not need any. Fluorescents on motion sensors, off by default, coming on in a bay when a body walks into it and going off again four minutes later. The default state of the building is dark. It has been dark for years, doing its work perfectly, and it will only be lit again when something has gone wrong enough to send somebody in.
I built ten cabinets and lit them with lamps I own, and even so the honest exposure of the aisle is black with one point in it.