10 seconds exposure using Tri-X 100 film.
These images of comet White-Ortiz-Bolelli was taken on May 27, 1970, when the comet was magnitude 4.3 and had a tail 15 degrees long to the naked eye, despite being deep in the evening twilight.
The photographs were taken with a home-made camera based on a 50mm f/2.5 slide projector lens. The film was cut from 120 sized roll film and placed in a frame made from a tin can. The body of the camera was a simple box of wood. To stop stray light hitting the film, the back of the box was covered with a black cloth. The exposure was taken by removing a cover from the lens, hopefully without bumping it! The camera was aimed by sitting it on a folding ladder and holding it with one hand while taking the lens cover off with the other.
The comet is faintly visible near the lower left-hand edge, with the tail streching up and slightly right, passing to the right of Betelguese, which is the bright star near the upper left-hand edge.
