infrared photography

(redirected from Infra-red photography)
Also found in: Dictionary.

infrared photography

[¦in·frə¦red fə′täg·rə·fē]
(graphic arts)
Photography in which an infrared optical system projects an image directly on infrared film, to provide a record of point-to-point variations in temperature of a scene.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Infrared Photography


(also IR photography), the production of photographs using infrared radiation. Photographs can be taken in IR radiation in several ways. The simplest method is that of direct photography, using photographic plates or film that are sensitive to IR radiation. In this case a light filter that passes IR radiation but is opaque to visible light is mounted on the camera lens. Modern materials for infrared photography have a sensitivity threshold in the long-wave region of λ = 1.2 microns (μ).

The sensitivity of infrared film and plates is relatively low; therefore, at low illumination intensities apparatus consisting of an image converter and a standard photographic camera is used for infrared photography. The image converter, which is placed in front of the camera lens, converts the invisible infrared image into a visible image, simultaneously increasing its brightness. Such apparatus makes possible the production of photographs on standard film in complete darkness and with a low-powered IR radiation source. The sensitivity threshold in the long-wave region is dependent on the photocathode of the image converter and does not exceed λ = 1.2 λ.

Special apparatus makes possible the production of infrared photographs in the region where λ > 1.2 η. One such device, the infrared vidicon, is a television system in which the screen of the camera tube is made of photoconductive semiconductor materials, which change their electrical conductivity under the influence of infrared radiation. A visible television image appearing on the screen of the picture tube is then photographed by a standard camera. The long-wave limitations of the vidicon depend on the nature of the material of the photoconductive screen and on its temperature; at T = 79°K (with liquid nitrogen cooling) the limit is λ ≈ 5 μ; at T = 21°K (with liquid hydrogen cooling), λ ≈ 20 μ.

Infrared photography makes it possible to obtain additional data about an object (as compared to photography in visible light or visual observation). When passing through haze or fog, infrared radiation is dispersed to a lesser degree than visible radiation, making possible the production of sharp photographs of remote objects over distances of hundreds of kilometers. Because of the difference in reflection and transmission coefficients between the visible range and the infrared range, infrared photographs show details invisible to the eye on standard photographs. These particular features of infrared photography are widely used in botany for studies of plant diseases, in medicine during diagnosis of skin and vascular diseases, in criminology for detection of forgeries, in infrared aerial surveying, and in astronomy for photographing stars and nebulas. Infrared photographs can be taken in complete darkness.

Devices are also made that are capable of recording thermal IR radiation by an object whose temperature is different at different points. The intensity of IR radiation at each point is recorded by the receiver and is converted into a light signal, which is in turn recorded on photographic film. The image produced in this case is not an infrared photograph in the usual sense, since it depicts only the temperature distribution on the surface of the object. Such devices are used in detecting overheated areas of machines and in infrared aerial surveying to produce a thermal map of a locality.


Clark, W. Photography by Infrared, 2nd ed. New York, 1946.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

infrared photography

Photography employing an optical system and direct image recording on film sensitive to near-infrared wavelength (infrared film). This should not be confused with infrared imagery. The term infrared photography is misleading, in that the infrared portion of the spectrum extends approximately from 0.7 to 300 microns in wavelength. Infrared photography, on the other hand, normally includes wavelengths no greater than 1 micron. The recording of near infrared (i.e., at wavelengths between 0.7 and 1.5 microns) does not differ significantly from the recording of visible radiation and is called near infrared to distinguish it from imagery obtained with longer wavelengths of infrared energy.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved
References in periodicals archive ?
Category Description Source Aerial photography Black & white photography National Aerial for 1993 and 1998 Photography Project (NAPP)--distributed to field offices by NRCS Black & white photography Flown for USDA and for 1940 later digitally preserved by Illinois Department of Natural Resources Black & white photography Champaign County for 2002 Color-infrared photography Purchased by CCSWCD collected from 1984-1998 from local pilot Color infra-red photography USDA-FSA flown in 2004 Cadastral USDA field and tract USDA-FSA boundaries Tax parcel center points Champaign County (tax parcel boundaries are Regional Planning pending) Commission Sections, townships, and Digitized by CCSWCD to county boundary match NAPP photography.
Research can be art historical - recent exhibitions have rescued from comparative obscurity the fascinating career of Thomas Jones, whose paintings and memoirs provide a unique record of an 18th century artist's life, and the Welsh seascapes of the Pre-Raphaelite painter John Brett - or it can be technical, using modern analytical techniques, such as x-ray and infra-red photography, to reveal how an artist actually worked.
"Many of the fragments are so deteriorated you can't see anything except through infra-red photography," Falk says.
David Hemsoll has written an article about the painting for the scholarly Burlington Magazine , revealing the results of new scientific research including paint analysis and infra-red photography, which has given a first glimpse of Simone's underdrawing.To give a sense of just how different it might have looked when first painted, the Barber commissioned Peter Murphy, who specialises in latter-day icons painted in tempera, to make a reconstruction of the painting, restoring it to its original format aspart of a folding triptych.
Using infra-red photography, painstaking analysis of inks, careful study of the slope and spacing of letters and the like, Reed goes further than any previous editor towards establishing the text as it stood in late February 1806.