Additive colour is based on the mixing of light of different colours. By mixing three light sources with the primary colours red, green and blue, any other colour can be created. The starting point is black (no light) and subsequently coloured light is added (hence the name “additive”) and mixed. A balanced mix of the… Continue reading Additive colour
Photography technique
Guillotine shutter
The guillotine shutter is a simple shutter construction that uses a blade to pass across the lens. Early guillotine shutters were simple gravity-driven constructions.
Negative image
An image, usually on transparent glass plate or film, in which the lightest areas of the photographed subject appear darkest and the darkest areas appear lightest. Negatives are used to make positive prints on paper or glass.
Orthochromatic emulsion
Monochrome photographic emulsion that is sensitive to only blue and green light, and thus can be processed with a red safelight.
Panchromatic emulsion
Panchromatic emulsion is a monochrome photographic emulsion that is sensitive to all wavelengths of visible light. Black & white tones are displayed in a manner as perceived by the human eye. The panchromatic emulsion was invented in 1905 and was also crucial for early colour processes that made use of additive colour and the screen… Continue reading Panchromatic emulsion
Panoramic photography
Panoramic photography or wide format photography is a technique that captures images with horizontally elongated fields of view. The aspect ratio of stereo formats was also useful for panoramic photography. Instead of capturing a stereo pair, one single stereo photo was captured. Some stereo cameras could also be used for panoramic photography. An example is… Continue reading Panoramic photography
Screen process
The screen process is used by early colour photography processes that were based on additive colour. The separation of three primary colours is effected by a transparent colour filter screen that is covered with a mosaic of grains or a grid of fine lines and/or dots in three primary colours. During the exposure of a… Continue reading Screen process
Tailboard camera
A Tailboard camera is a view camera with bellows. The camera is focussed by adjusting the rear ground glass forward or backward until the image on the matte screen is sharp.
View camera
A view camera is a large camera in which the lens forms an inverted image on a ground glass screen directly at the plane of the glass plate negative or film sheet. View cameras support options to control focus and convergence of parallel lines. It’s done by moving the front and/or rear parts of the… Continue reading View camera