"A hemispherical limestone boulder which I pinhole on 25th April 2021 (WPPD) using Fomapan 100 4x5 film in a Noon 45W Pinhole Camera. Developed in R09 for 30 minutes 1:100 and agitated once every five minutes for five seconds. The camera is made in Poland from Walnut. Exposure 14 sec; f273, 60mm f/l."