Scientific Photography and Applied Imaging

Sidney Ray

• Publisher: Routledge
• Year: 1999
• Print ISBN: 9780240513232
• eBook ISBN: 9781136094378
• Topic: Mezzi di comunicazione e arti performative
• Subtopic: Media digitali

WINNER OF THE 2001 KRASZNA-KRAUSZ PHOTOGRAPHY BOOK AWARD (Technical Photography category)

The only definitive book to fully encompass the use of photography and imaging as tools in science, technology and medicine. It describes in one single volume the basic theory, techniques, materials, special equipment and applications for a wide variety of uses of photography, including: close up photography and photomacrography to spectral recording, surveillance systems, radiography and micro-imaging.

This extensively illustrated photography 'bible' contains all the information you need, whether you are a scientist wishing to use photography for a specialist application, a professional needing to extend technical expertise, or a student wanting to broaden your knowledge of the applications of photography.

The contents are arranged in three sections:
· General Section, detailing the elements of the image capture process
· Major Applications, describing the major applications of imaging
· Specialist Applications, presenting an eclectic selection of more specialised but increasingly important applications

Each subject is introduced with an outline of its development and contemporary importance, followed by explanations of essential theory and an overview of techniques and equipment. Mathematics is only used where necessary. Numerous applications and case studies are described. Comprehensive bibliographies and references are provided for further study.

1 Introduction

1.1 Historical development

The scientific applications of photography and imaging date from the earliest days of the introduction of photographic processes such as the Daguerreotype and Calotype (1839), and the wet plate (1851), although it was realized that the spectral sensitivity was limited to UV and blue only. The work of Vogel in 1873 (Vogel, 1875) gave green (orthochromatic) sensitivity and later extended to red (early 1900s) and IR (1930s). General technical accounts of photographic technology are given by Eder (1945), Mees (1926, 1942, 1961), Suptitz (1990) and by Ostroff, (1987).

One of the first recorded scientific images was that of the moon taken in 1840 by J. W. Draper of New York with a 20 minute exposure. This image sold well to the public and later in stereo form. Remarkably, in 1839 Sir John Herschel noted the presence and effects of UV and IR radiation with the new photographic process of Fox Talbot. Various notable early uses and achievements of photography applied to scientific research have been detailed by Darius (1984). The relevant properties of early lenses for photography have been detailed by Kingslake (1989), Ray (1990a) and von Rohr (1899). Numerous books detail early cameras and equipment (Coe, 1978; Stuper, 1962).

An early account of scientific photography was given by H. Baden Pritchard in Nature (1872), reprinted in the British Journal of Photography of 19 July 1872, but in comparison with pictorial and commercial uses of photography, few accounts have been given of the development of the topic, however, a number of reviews have been published from time to time on specialist topics which also contain extensive bibliographies covering periods of time and prior usage. These include: astronomy by de Vaucouleurs (1961) and Hoffleit (1950), endoscopy by Gardner (1992), time lapse photography by Jones (1969), high speed photography by Arnold and Hewitt (1967), and nature photography by Angel (1986). Boni (1962) provides comprehensive literature details on most photographic topics. The pioneering work of Hurter and Driffield on the quantification of the photographic process is discussed by Ferguson (1920). Later progress in photographic technologies is documented by Anonymous (1970), Coote (1993), Edgerton (1970), Fielding (1967), Friedman (1968), Gruner (1977), Helwich (1968), Hillson (1969), Hyzer (1962), Roosens and Salu (1989, 1994), Ryan (1977), Spencer (1951, 1955), Tupholme (1945).

A few early textbooks manage to be comprehensive in the contemporary coverage of both photographic science, equipment and applications, such as those by Clerc (1937), Conrady et al. (1923), Hasluck (1900), Henney and Dudley (1939), Johnson (1909) and by Mack and Martin (1939), giving useful historical detail in the development and uses of the photographic process.

It is also possible to suggest a number of published papers which admirably cover the application of a range of techniques in specific fields. For example, a detailed account of the scientific application of photography to the examination of paintings by recording using non-visible radiations is given by Townsend (1992). Likewise, Lidbetter (1990) covers the typical wide range of techniques used in modern industry, while Ray (1989a–e, 1990b) and Rolls (1975) describe broad fields of application. The impact of new technology on established practices in scientific photography has been investigated by Rolls (1989).

The significance of photographic records either in establishing a scientific theory or in detection of predicted effects or phenomena has been detailed by Darius (1984) and the use of scientific photography as an aid to explaining complex scientific concepts and research projects is exemplified by the work of Fritz Goro as shown in a portfolio introduced by Gould (1993), and by Thomas (1998).

Finally, details of the concomitant development of the photographic manufacturing industry and biographies of personalities also provide useful background material, such as the publications of Anonymous (1989), Brayer (1996), Chapman (1995), Coe (1973), Collins (1990), Edgerton (1979), Haas (1976), Hercock and Jones (1979), Hyde (1976), James (1990), Jenkins (1975), Levenson (1988), Marder and Marder (1985), Mort (1989), Schaaf (1992), Taft (1964) and Winston (1996).

1.2 Photography as a tool

1.2.1 Scientific applications

Professional photography has various specialist areas, some of which, such as advertising photography and photojournalism, by the very nature of their images generate wide interest, admiration and appreciation. By comparison, applied photography in its role as a scientific tool has a low public profile, although perhaps unbeknowingly its images are ubiquitous and play roles in many consumer products, health and civic matters.

In the UK alone there are identifiably several hundred applied photographers, working for the government or industry or in research institutions, universities and hospitals. Their primary role is the production of images for recording, measurement and interpretation purposes in the fields of science, technology and medicine and the related onward communication of results in the form of audiovisual material and reports.

The specialism may be identified as being ‘photography and imaging used as scientific tools to provide records that cannot be made in any other way’. Naturally, ‘photography and imaging’ includes cinematography, video and digital imaging, for all of these visual media have specific attributes individually of value, and given the nature of the subject the most appropriate medium is chosen.

In particular, applied imaging is a means of extending imagery beyond the limits of human visual perception, producing permanent records for analysis and evaluation of the subject and processes involved. The emphasis is on the precision and accuracy of the imagery, as witness the growth of the microelectronics industry from techniques such as photofabrication and micro-imaging. Absolute objectivity and absence of ambiguity is also necessary such as in images for clinical, forensic and public enquiry work. Many scientific images may have little meaning except to specialists and lack general visual appeal except perhaps in the case of the more morbid examples. On the other hand, a significant and growing number of suitable pictures are used in the editorial and advertising contents of popular and learned journals in science, medicine and education where their possibly normally non-visible or purely serendipitous nature can attract non-specialist attention. Additionally, there have been numerous compilations of such images published in book form in recent years, covering topics such as astronomy, natural history, aerial photography and human physiology.

As well as the techniques of studio and location photography, applied photography uses specialist equipment to record subjects which may emanate outside the visible spectrum, or that may move too slowly or too fast for changes or events to be readily perceptible or that may simply be too small or too far away to be examined visually in detail. Additionally, photography may be utilized in situations that are biologically hazardous, giving permanent records that may provide accurate dimensional information about the subject without the need for physical contact.

Images may further be optically reduced for storage purposes and retrieved as required. Image storage in digital form allows processing to enhance and emphasize parts of the image to aid interpretation and comprehension. The ongoing replacement of silver halide based images by electronic or digital counterparts, which is a concern in some sectors of the imaging industry, has not been a problem in applied photography. Rather there has been a very satisfactory, indeed exemplary, merging of the two technologies and the most appropriate system is chosen or a suitable hybrid devised for the job in hand. The role of an applied photographer, who very often is a highly qualified person, is now perhaps less in direct involvement with recording but rather in advising the scientist or researcher as to the most efficient and cost-effective method of obtaining results and the initial design and setting-up of systems.

The full scope of applied photography may perhaps best be explained by a brief overview of some of the topics covered later in detail.

1.2.2 Spectral recording

Human visual perception and conventional photography are limited to the spectral band from 400 to 700 nm. Useful information about the nature or behaviour of a subject is obtained from its spectral signature or pattern of emission and reflectance outside the visible region, particularly in the ‘near’ ultraviolet (UV) at 300 to 400 nm and the ‘near’ infrared (IR) from 700 to 1300 nm. Both regions can be recorded by silver halide materials with minor modifications of technique.

All film materials respond to UV but this can be absorbed before it reaches the silver halide crystal. Optical glass in lenses and filters, the gelatin of emulsions and even the atmosphere remove actinic radiation. Lenses of fluorite and quartz and low gelatin materials may be needed. Fortunately, sources such as electronic flash and daylight are rich in UV. Apart from such ‘direct’ UV photography as used for dermatology (skin) and plant studies, the recording of coloured light emitted by fluorescence from UV irradiation requires conventional colour photography, albeit with inconveniently long exposures. UV fluorescence photography is used in non-destructive testing and in analysis for the ...

Table of contents

• Cover
• Half Title
• Title
• Copyright
• Contents
• Preface
• Acknowledgements
• Abbreviations and symbols used in text
• 1 Introduction
• 2 Limits of human visual perception
• 3 Experimental design
• 4 Light and radiation sources
• 5 Optics and lenses
• 6 Camera systems for data capture
• 7 Shutter systems
• 8 Lighting
• 9 Exposure determination
• 10 Image recording systems
• 11 Image processing, analysis and management
• 12 Close-up photography and photomacrography
• 13 Photomicrography
• 14 Micro-imaging
• 15 Photofabrication
• 16 Stereoscopic (3D) photography
• 17 Photogrammetry
• 18 Aerial photography
• 19 Remote sensing
• 20 Infrared recording
• 21 Imaging systems
• 22 Ultraviolet recording
• 23 Radiography
• 24 Photographic visualization
• 25 High speed photography and photonics
• 26 Surveillance systems
• 27 Low light level imaging
• 28 Telephotography
• 29 Cavity and endoscopic systems
• 30 Underwater photography
• 31 Panoramic photography
• 32 Peripheral photography
• 33 Fisheye lens photography
• 34 Holography
• Index