Promotional Item from Camera Weekly Magazine
Many organisations supplied some form of exposure calculator, and the rotary format was quite common. Ilford marketed such a device from as early as 1896 (RH). Contemporary to the Johnson calculators, the ‘Focal Press’ supplied a neat 3-fold exposure guide with a rotary calculator, including advice on stage, flash, nighttime, artificial light, indoor daylight and colour photography. It had many reprints.
Major film-makers supplied, free of charge, simple pocket exposure guides, often laminated to improve their resilience. Indeed, the instruction leaflet packaged with films contained a guide to exposure that was perfectly adequate for most outdoor subjects in daylight for many years. Special guides were published for events like bonfire night (5th November) and street scenes of Christmas decorations. They encouraged people to use their cameras under more unusual circumstances, which was good for product sales.