An original fiction passage set in the nineteenth century.
The youngest child shifted again just as Mr Pritchard lifted the brass cap from the lens. In the darkroom, a pale blur rose on the plate where her face should have been. When he returned, the family asked whether the portrait was complete. Mr Pritchard bowed and invited them to hold still for one final attempt. He had left his temper in the darkroom, shut away with the ruined plate.
Identify the phrase that shows Mr Pritchard keeping his irritation from the family.