Forensic Photography Techniques (PDF)

SCIENTIFIC AND TECHNICAL PRINCIPLES OF FORENSIC PHOTOGRAPHY Prof. Divine Grace B. Bascugin, RCrim.  EARLY LEGAL APPLICATION AND BRIEF HISTORY OF PHOTOGRAPHY  A: CRIMINAL APPLICATIONS 1854 - Maddox developed dry plate photography eclipsing Daguerre's wet plat...

SCIENTIFIC AND TECHNICAL PRINCIPLES OF FORENSIC PHOTOGRAPHY Prof. Divine Grace B. Bascugin, RCrim.  EARLY LEGAL APPLICATION AND BRIEF HISTORY OF PHOTOGRAPHY  A: CRIMINAL APPLICATIONS 1854 - Maddox developed dry plate photography eclipsing Daguerre's wet plate on tin method. This made practical the photography of inmates for prison records. 1859 - Enlarged photographs of signature were presented in a court case involving forgery in California, USA. 1864 - Odelbercht first advocated the use of photography for the identification of criminals and the Early photographs of accused and arrested persons were posed as examples of the documentation of evidence and crime scenes. START 09/30/2024 3 1882 - Alphonse Bertillon who initiated the Anthropometric measurements for personal identification was also involved in various means of documentation by photograph. 1902 - Dr. R. A. Reis, a German scientist trained in Chemistry and Physics at Lausanne University in Switzerland. He contributed to the use of photography in forensic science and established the world's earliest crime laboratory that serviced the academic community and the Swiss police. START 09/30/2024 4 1910 - Victor Balthazard developed a method of photographic comparison of bullets and cartridge cases which acted as an early foundation of the field of ballistics. START 09/30/2024 5 HISTORICAL BACKGROUND OF PHOTOGRAPHY IMPORTANT DATES/ PERSONALITIES IN PHOTOGRAPHY  Chinese and Greek philosophers (5th-4th Centuries Describe B.C.)principles of optics and the camera. the basic Isaac Newton (1664-1666) Discovered that white light is composed of different colors. Johann Heinrich Schulze (1727)  Accidental creation of his first photo sensitive compound  Mixed chalk, nitric acid and silver in a flask  Discovered that silver nitrate darkened upon exposure to light. START 09/30/2024 7 Joseph Niepce 1814  Achieved the first photographic image using an early device for projecting real-life imagery called a camera obscura. However, the image required eight hours of light exposure and later faded. Louis Daguerre 1837  Create images on silver-plated cooper, coated with silver iodide and “developed” with warmed mercury  His first daguerreotype process, an image that was fixed and did not fade and needed under thirty minutes of light exposure  Boulevard du Temple- first ever photograph taken START 09/30/202 8 William Henry Talbot 1841  Patented the Calotype process  The first negative-positive process making possible the first multiple copies.  Created permanent images using paper soaked in silver chloride and fixed with a salt solution Frederick Scott Archer 1851  Invented the Collodion process so that images required only two or three seconds of light exposure.  Improves photographic resolution by spreading a mixture of collodion and chemicals on sheets of glass.  Unlimited reproduction, published but not patented. START 09/30/202 9 Oliver Wendell Holmes 1861  Invented stereoscope viewer Richard Leach Maddox 1871  English Doctor  Proposes the use of an emulsion gelatin and silver bromide on a glass plate, “DRY PLATE PROCESS” Reverend Hannibal Goodwin 1898  Patented celluloid photographic film START 09/30/202 10 George Eastman1884  Invented flexible, paper-based photographic film  Developed dry gel on paper, or film, to replace the photographic plate  He sets up Eastman Dry Plate Company in Rochester, NY at the age of 24  Eastman Dry Plate Company is founded (1880)  Patented Kodak roll-film camera (1888)  Kodak markets Kodachrome film (1935)  George Eastman and Edwin Land were inducted into the National Inventors Hall of Fame (1977)  Eastman Kodak announced Photo Compact Disc as a digital image storage medium. (1990) START 09/30/202 11 Chester Carlson 1942  Received a patent for electric photography (xerography) Edwin Land 1948  Launches and marketed the Polaroid camera START 09/30/202 12 1913/1914  The first 35mm camera was developed 1927  General Electric  Invented the modern flash bulb 1932  First light meter with photoelectric cell is introduced START 09/30/202 13 1960  EG&G  Developed extreme depth underwater camera for U.S. Navy. 1963  Polaroid introduces the instant color film 1968  Photograph of the Earth is taken from the moon. The photograph, Earthrise, is considered one of the most influential environmental photographs ever taken 1973  Polaroid introduces one-step instant photography with the SX-70 camera START 09/30/202 14 1978  Konica  Introduced the first point-and-shoot autofocus camera 1980  Sony  Demonstrated first consumer camcorder for capturing moving pictures 1984  Canon  Demonstrated the first digital electronic still camera START 09/30/202 15 1985  Pixar  Introduced the digital imaging processor 1999  Kyocera Corporation  Introduced the VP-210 Visual Phone, the world's first mobile phone with a built-in camera for recording videos and still images START 09/30/202 16  THE OPERATION OF VARIOUS PHOTOGRAPHIC EQUIPMENT, ITS PARTS AND FUNCTIONS IN FORENSIC INVESTIGATION Chapter 2  ANALOG AND DIGITAL CAMERA START 09/30/2024 18  DIGITA ANALOG L Film photography, also Captured by collecting light known as analog using an electronic image photography sensor. chemical processes are Can be viewed used to capture an image immediately on the on some kind of light- display of the camera or sensitive film (or paper or transferred onto a different plate) computing device for editing, viewing, and sharing. START 09/30/2024 19  ANALOG DIGITAL START 09/30/2024 20  RESOLUTION When it comes to both digital and analog formats, photographers want to know that their efforts will result in sharp, high-resolution photographs. Both methods of measurement can be correlated with each other and thus compared for equivalent resolution. START 09/30/2024 21  Digital Noise / Film Grain The random appearance of small textures within a photograph may be referred to as digital noise or film grain.  In Analog film, grain is the result of small chemical particles that have not received enough light.  In Digital image sensors, noise is the result of unwanted signals created by the camera's digital circuitry (can be due to excess heat or a sensor's ability to handle unruly signals in the airwaves). START 09/30/2024 22  International Organization for Standardization START 09/30/2024 23   Also known as ISO  ISO Sensitivity is a standard set by the International Organization for Standardization (ISO) that represents International sensitivity to light as a numerical value. Organization A higher number indicates a higher for sensitivity and a greater ability to capture Standardization light. The ISO Sensitivity is set and changed in the shooting settings menu. START 09/30/2024 24   Increasing the ISO of a digital camera or selecting high-speed film will make your photographs more susceptible to noise and grain.  With black and white images, some artists view the grain as adding character, and thus not as a International negative point. Organization  Noise/grain is that film may be a better medium for for capturing long-exposure photographs. Standardization  Image sensors must be operated at low temperatures to avoid thermal noise. START 09/30/2024 25  DYNAMIC RANGE START 09/30/2024 26  While the dynamic range of an Image is a complex process that takes into account the sensor used, the type of file Dynamic compression, and other Range factors, digital is ultimately winning against the analog film. START 09/30/2024 27  FILM SPEED START 09/30/2024 28   Shooting in low light conditions, digital image sensors easily take the cake.  Film can usually be found available in speeds between 100 and 3200  Although 6400 film does exist. digital camera Systems can match the noise produced by analog cameras in these ranges Film Speed  Analog film can be pushed or pulled multiple stones when needed, but the amount of contrast within the image is affected. START 09/30/2024 29  DEFINITION OF TERMS Camera Lightproof box with a means of forming an image, with a means of holding sensitized materials, and with a means of regulating the amount of light that enters the camera at a given time. START 09/30/2024 30  DEFINITION OF TERMS Circle of Confusion Overlapping circle patches of light represent each patch of light on the subject. It represents unsharp images, but the human eyes see them as acceptably sharp. START 09/30/2024 31  DEFINITION OF TERMS Depth of Field Distance between the nearest object and the farthest object that appears to be focused when the lens is focused in infinity. START 09/30/2024 32  DEFINITION OF TERMS Film Speed Control This control is utilized by manipulating the ASA/ISO/DIN dial of the camera. The shutter and the f/numbers are both Controlling the system of the rays of light that enter. START 09/30/2024 33  DEFINITION OF TERMS Focus It is how the object distance is estimated or calculated to form sharp or clear images. START 09/30/2024 34  DEFINITION OF TERMS Hyperfocal distance This is the nearest distance at which a lens is focused with a given particular diaphragm which will give the maximum depth of field. START 09/30/2024 35  DEFINITION OF TERMS Parallax It is the difference between what is seen through the viewfinder and what is exactly recorded on the film. START 09/30/2024 36  DEFINITION OF TERMS Relative Aperture The speed of light gathering power of lens equal to the duration of the focal length to the diameter of its lens pupils or the relative brightness of the image produced by the lens as compared with the brightness of the object. START 09/30/2024 37  TYPES OF CAMERA START 09/30/2024 38  REFLEX CAMERA Single-lens Reflex Camera The term single lens means that only one lens is used for both viewing the scene and taking photograph of it. thereby preventing parallax. START 09/30/2024 39  REFLEX CAMERA Twin Lens Reflex Camera Two separate lenses one for viewing and one for focusing and the second usually mounted under the first, transmits the light to the focal plane for recording. Its two lenses focus in unison so that the top screen shows the image's sharpness and framing as recorded on the film in the lower section. START 09/30/2024 40  Polaroid Still Camera This camera is restricted in its uses but is ideal for instant photographs when there is no requirement for enlargement. START 09/30/2024 41  Underwater Camera This is designed for underwater photography. START 09/30/2024 42  Panoramic Camera Used for landscaping photography. It is easy to use by encompassing 120°, 180°, and 360° view of one exposure. START 09/30/2024 43  Still Video Camera Images can be stored on videotape equipment with a floppy disc - a disc that can hold about 50 images or more. START 09/30/2024 44 MAIN PARTS OF CAMERA  Light Tight Box a box designed to keep light out and serve as a frame to hold other parts. START 09/30/2024 46  Lens A disc of transparent glass generally bounded by two spherical surfaces capable of forming an image. START 09/30/2024 47  Shutter An adjustable mechanism that regulates the amount of light reaching the film by varying the length of time. This is a control by which you can determine how long in time the lens will remain open for light to be recorded on the film. START 09/30/2024 48  SHUTTER Central Shutter It is made up of overlapping blades powered by a spring. Located between the aperture and the lens or in between the lens. Opens from the center towards the sides closes vis-à-vis. START 09/30/2024 49  SHUTTER Focal Plane Shutter It consists of two metal blinds that open progressively or made of black cloth and generally located very near the focal plane. START 09/30/2024 50  HOLDER OF THE SENSITIZED MATERIAL located at the opposite side of the lens designed to hold firmly the sensitized material to prevent the formation of the multiple or blurred image START 09/30/2024 51  VIEW FINDER designed to determine the field of view of the camera or the extent of the coverage of the given lens START 09/30/2024 52  Exposure Triangle START 09/30/2024 53 START 09/30/2024 54 THANK YOU!