His subject choice was determined by his superiors, which is perhaps why Chojnacki's images represent the most accurate known photographic documentation of the Old Town barricades, trenches and fortifications. Negatives sent on the orders of the military authorities to a laboratory in central Warsaw to be printed were lost. The only ones that remain are those that were buried in the courtyard of a house at 40 Freta Street before the Old Town was evacuated – 15 films out of 50 exposed, in 6x9 cm format. Chojnacki photographed the Uprising with his own SLR camera, with materials obtained from the regional leadership as well as those he had gathered himself before the outbreak of the Uprising.