Scotograph is a term used to describe a device that is used to trace images onto a surface. The spelling of the word is pronounced as /skəʊtəˌɡrɑːf/. The word is made up of two parts- 'scoto' which means darkness and 'graph' which means to write, therefore together this word refers to writing in darkness. The term is often used in the field of photography and art, and is a helpful tool for artists and designers to transfer images precisely onto their desired surface.
A scotograph refers to a visual perception phenomenon where an individual experiences an afterimage or a persistent image on the retina of the eye. This optical occurrence can be characterized as the subjective perception of a form or image that persists even after the original stimulus is no longer present.
Scotographs are commonly observed when an intense light or visual stimulus is viewed for a prolonged period, causing temporary fatigue or bleaching of the retinal photoreceptor cells. Once the stimulus is removed or the eyes are closed, the scotograph arises as a result of an imbalance in the relative sensitivity of the different retinal photoreceptors. The afterimage perceived by the individual is typically in the complementary color to the original stimulus, often persisting for a brief period of time.
Scotographs can manifest in various forms, including positive afterimages where the color and shape of the original stimulus are retained, and negative afterimages where the complementary color is seen against a neutral background. The duration of scotographs may differ depending on the intensity and duration of the original stimulus, as well as individual variations in perception and visual adaptation.
This visual phenomenon has been utilized as a tool in art, optical illusions, and color theory to create visual effects and enhance compositional elements. Furthermore, scotographs have also been studied in the field of vision science to better understand the anatomy, physiology, and functioning of the human visual system.
1. An appliance for aiding one to write in straight lines in the dark or to aid the blind to write. 2. An impression made on a photographic plate by a radioactive substance without the intervention of any opaque object other than the screen of the plate.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
An instrument to enable one to write in the dark, or to enable one who is blind to write.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.
The word "Scotograph" is a combination of two Greek roots: "scoto-" and "-graph".
The first part, "scoto-", comes from the Greek word "skotos", meaning "darkness" or "shadow". It is derived from the Proto-Indo-European root *(s)kewd-, which also gave rise to words like "skiapod" (a person whose shadow is believed to be detached from his body, creating a second person) and "scotophobia" (the fear of darkness).
The second part, "-graph", comes from the Greek word "graphos", which means "writing" or "drawing". It is derived from the Greek verb "graphein", meaning "to write" or "to draw". This root is also found in words like "photograph" and "autograph".