FOREN101-2024-2025-prelim-notes.docx

**FOREN 101:** **Forensic Photography** **PRELIM COVERAGE** ALLEN Z. BALLENAS, RCrim, MSCJ JEFFREY EFONDO, RCrim, MSCJ **THE DISCOVERY OF PHOTOGRAPHY** **The light projection** **Light projection.** In light projection, images of objects may be projected for viewing by using a simple hole. !...

**FOREN 101:** **Forensic Photography** **PRELIM COVERAGE** ALLEN Z. BALLENAS, RCrim, MSCJ JEFFREY EFONDO, RCrim, MSCJ **THE DISCOVERY OF PHOTOGRAPHY** **The light projection** **Light projection.** In light projection, images of objects may be projected for viewing by using a simple hole.  **Light Projection as the Concept of the Pinhole Camera** **The advent of the "camera obscura"**  **The inventor of the camera obscura** **GENERAL CONCEPTS OF PHOTOGRAPHY** **Concept of Photography** **The Common uses of photography** **Basic Components/ Elements of Photography** 1. **Object** -- the subject of the picture, and can be anything under the sun. 2. **Light** -- may be from different sources, principally daylight. 3. **Camera** 4. **Sensitized Material** (film and photo paper) **Basic definition of terms:** 1. **Photograph** is the mechanical and chemical result of photography. To produce a photograph, light is needed aside from sensitized materials (film and paper). 2. **Photography** is the art or process of producing images of objects by action of light on a sensitized surface with the aid of an image-performing device known as a camera and the chemical process involved therein. 3. **Police Photography** refers to the art or science which deals with the study of the principles of photography, the preparation of photographic evidence and its application to police work. 4. **Forensic photography** is the art or science of photographically documenting a crime scene and evidence for laboratory examination and analysis for the purpose of court trial. 5. **Police Photographer** -- is one who is tasked to take photographs of crime scene, suspects or any physical evidence found at the crime scene. **THE PRINCIPLES OF LIGHT** Light is one of a number of known forms of **radiant electromagnetic energy** which travel in wave motion.  - This form of energy travels at a speed of about 186,000 miles / 300,000 Km per second in air, but they differ in wavelength and frequency. - - - **The Four Photographic Rays of Modern Photography** 1. X-rays 2. Ultraviolet rays 3. Visible light 4. Infrared rays **The Electromagnetic spectrum** **RAYS** **WAVELENGTH** ------------------ ------------------ x-rays 1 -- 30 nm Ultraviolet rays 30 -- 400 nm Visible light 400 -- 700 nm Infrared rays 700 -- 1000 + nm **The difference between light and radiation** The Webster's Dictionary defines light as a radiant electromagnetic energy that can be seen by the naked eye. The scientific definition of light is the aspect of radiant energy of which a human observer is aware through the visual sensations which arise from the stimulation of the retina of the eye. - - **THE WHITE LIGHT** When all the wavelengths between 400 -- 700 nanometers are presented to the eye in nearly equal quantity, we get the sensation or perception of colorless or **white light.** If a narrow beam of white light is allowed to pass through a prism it will bend the light of shorter wavelength more than those with longer wavelength thus spreading them out into the visible spectrum. These are the color of the rainbow such as: red, orange, yellow, green, blue, violet. If we divide the wavelength of visible light (400 -- 700 nn) equally into three (from 400 -- 500, from 500 -- 600, and from 600 -- 700 nn). We will produce the **BLUE**, **GREEN** and **RED** colors. These are known as the **three primary colors of light.** **Additive Color Mixture** 1. 2. 3. 4. In this aspect, the three Secondary colors of light were: 1. 2. 3. **Subtractive Color Mixture** 1. 2. 3. 4. **THE BENDING OF LIGHT AND THE SOURCES OF LIGHT** 1. - - 2. 3. **Kinds of Object as How They Behave To Light** 1. **Transparent Objects** - allows sufficient visible light to pass through them that the object on the other side may be clearly seen. 2. **Translucent Objects** - allows light to pass, however diffuse it sufficiently that objects on the other side may not be clearly distinguished. In some cases the objects on the other side may be recognizable but sharp detail and outlines are obscured. 3. **Opaque Objects** - so greatly diffuse the light that recognizing the object on the other side is very difficult if not impossible. **The Sources of Light:** 1. - 1. - 2. - 3. - 2. 1. **Continuous Radiation** -- are those that can give illumination continuously like fluorescent lamp, gas lamp etc. 2. **Short Duration** -- a flash unit gives a brief flash of light. **POLICE PHOTOGRAPHY AND OTHER PHOTOGRAPHY RELATED TO POLICE PHOTOGRAPHY** **Police Photography** - Refers to the art or science which deals with the study of the principles of photography, the preparation of photographic evidence and its application to police work. **Other Photography Related To Police Photography** 1. **Photomacrography** or **Macro Photography** - Photographing of object at greater than 1:1 ratio up to nine (9) times magnification**.** - It is useful in making of enlarge copies of prints such as photographs of tampered serial number of firearms, engine number and chassis number of motor vehicle and the like. 2. - 3. **Infra-Red Photography** - It is the art or process of photographing or recording unseen objects by the naked eye by means of infra-red light. 4. **Ultra-Violet Photography** - It is the art or process of photographing unseen objects by the naked eye with the use of ultra-violet rays and filters. - The main purpose of photographing ultra-violet photography is to provide information about an object or materials, which cannot be obtained by ordinary photo methods. 5. **X-Ray Photography** - Recording internal structure of the body.