Russell Kirsch, developer of the pixel, 1929–2020

Russell Kirsch (previously) the American computer scientist who created a digital image of his son Walden in 1957, has died of Alzheimer's disease at age 91. The image, created on a SEAC, is widely considered one of the most influential images in the history of photography.

Via TechCrunch:

His research group used "a rotating drum and a photomultiplier to sense reflections from a small image mounted on the drum." In lieu of grid-based sampling of the image, a mask was placed on it pierced at intervals to create what amounted to pixels, though that term would not be used for years to come.

By measuring the reflectivity of the part of the image the machine could see and recording the result in a digital register (run by SEAC, among the country's first programmable computers), the system was effectively viewing the world — and by combining several scans at different settings they were able to store and show a grayscale image.

Even late in life, Kirsch continued to work on improving the technology, as shown in this 2011 presentation published by Cloudseed Films:

Image: Vimeo / Cloudseed Films