Opalka's studio in 1972, indicating the camera and lamp positions
he uses for photographing himself
Opalka is conscious that his program needs to retain an exceptionally high level of consistency. The canvases must remain the same size (195 x 135cm), the lines of numbers must stay straight and not vary in height, his black-and-white self-portrait photographs (shot at the end of the day when the painting is concluded for the evening) must be taken always against a white backdrop under the same lighting conditions, with the same expressionless frontal gaze, and so on. Only if he strives to keep his project utterly consistent, and consciously works to constrain any differences, however slight, will tiny, involuntary variations gradually become apparent. These little variations and differences might merely register the contingencies of everyday life, such as a pause to answer the phone, or a momentary slip of concentration, or whatever. Or, they reflect his inevitably aging bodily facilities.