Pointillism is a painting technique Georges Seurat (French, 1859–1891) created in the 1880s and employed in his famous painting A Sunday on La Grande Jatte—1884 (set on an island in the Seine River in France), in which small "points" of colors are applied in patterns to form the image.
Wanting to create a similar effect photographically, Irving Penn constructed a point source enlarger to be used with a zirconium arc lamp in 1951. While the enlarger afforded several advantages, including sharpness, Penn enlarged only very small sections of the 35mm negative. Because of the low resolution in each small area of reproduction and the sharpness of the enlarger, the resulting image emphasized the film grain, blurring fine details during the process.
When Penn began experimenting with printing techniques generally in the 1960s, he primarily used the point source enlarger to enlarge negatives for printing images in pigment on porcelain-coated steel sheets (see Couple Fishing from Bank of Seine, France ) and for contact printing on gelatin silver paper or in platinum (see View of Fez, Morocco  and Cretan Landscape  respectively).
Irving Penn. Couple Fishing from Bank of Seine, France, 1951. Gift of Irving Penn, 1996.251.