Contrast (within the scope of light and photography)
- Two or more items, objects or different colors that are seen as different. An example of high contrast would be red blood splatters on a glossy white wall. An example of low or no contrast would be red blood on a matching red color wall where you can’t see the red blood because they are seen as the same.
- ALS and FLS are acronyms that have multiple definitions. Within the lighting, photography, medical and legal industries, ALS can mean “Alternate Light Source”, “Alternative Light Source”, “Advanced Lighting Source” and/or “Amyotrophic Lateral Sclerosis” known as Lou Gehrig's Disease. FLS also has multiple definitions that can mean many things including: “Forensic Light Source”, “Fixed Light Source, “Full Length Shot”, Flu-Like Syndrome and “Family Law Section."
- Forensic Contrast Lighting, formally known as “ALS” and/or “FLS”, includes the use of any light that provides visual contrast, with our without the use of chemicals, filters or cameras.
- Forensic Contrast Photography describes the combined use of both Forensic Contrast Lighting tools and Forensic Contrast Camera systems. Both are used to find and photograph subject matter within the Ultraviolet and Infrared spectrum of light.
- Light is a form of overlapping electromagnetic radiation.
- Light is something that makes things visible.
- Visible light is light you can see without contrast lighting tools or contrast photography tools. It has a wavelength distance roughly between 400 nanometers and 700 nanometers. Visible light is a range within the Electromagnetic Spectrum.
- The distance, in nanometers, between successive crests or peaks of a wave is a wavelength.
- Ultraviolet radiation (UVR) has a wavelength distance roughly between 100 nanometers and about 400 nanometers. The scientific community has divided Ultraviolet Electrometric Radiation into three ranges. They are: UV-A (315 to 400 nm), UV-B (280 to 315 nm) and UV-C (100 to 280 nm).
- Ultraviolet Dark® is a trademarked term used to represent all three UV-A, UV-B, UV-C nanometer ranges of non-visible light within the Electromagnetic Spectrum. UV-A is from 315 to 400 nm, UV-B is from 280 to 315 nm, UV-C is from 100 to 280 nm and UV-D is from 400nm to 100nm. UV-D is better known as The "Ultraviolet Dark®".
- Violet light/radiation has a wavelength distance roughly between 350nm and 450nm, some of it is naturally visible
- Visible blue light/radiation has a wavelength in and around the 475nm mark. Blue is a range within the Electromagnetic Spectrum.
- Visible green light/radiation has a wavelength distance in and around the 510 nm. Lawn grass, for example, appears green because all of the colors in the visible part of the spectrum are absorbed into the leaves of the grass except green. Green is reflected, therefore grass appears green. Green is a range within the Electromagnetic Spectrum.
- Visible yellow light/radiation has a wavelength distance in and around the 570 nm. Low-pressure sodium lamps, like those used in some parking lots, emit a yellow (wavelength 589 nm) light. Yellow is a range within the Electromagnetic Spectrum.
- The visible orange light has a wavelength distance of roughly about 590 nm and is within the Electromagnetic Spectrum.
- Visible red light has a wavelength distance in and around the 650 nm. At sunrise and sunset, red or orange colors are present because the wavelength distances associated with these colors are less efficiently scattered by the atmosphere. Red is a range within the Electromagnetic Spectrum.
- Infrared light has a wavelength distance between roughly between 700 nanometers and 1,000 nanometers. The term "Infra-" means "lower than". Infrared light is a range within the Electromagnetic Spectrum.
- The “X-Ray” wavelength or spectrum is roughly between 0.03 nanometers and 3 nanometers. This range within the Electromagnetic Spectrum can be found between Ultraviolet and Gamma.
- The “Gamma” wavelength is shorter than the wavelength of X-Ray. It is roughly between 0.03 nm and 0.003 nanometers. Gamma Rays are less than the diameter of an atom. Gamma is a range within the Electromagnetic Spectrum.
- A kind of radiation including radio, microwaves, infrared radiation, visible radiation, ultraviolet radiation including X-ray radiation and gamma-ray radiation.
- Electromagnetic waves are produced by the motion of electrically charged particles. These “waves” are also called "electromagnetic radiation" because they radiate from the electrically charged particles.
- The electromagnetic spectrum is the range of all types of EM radiation including radio, microwaves, infrared, visible, ultraviolet, X-ray and gamma-ray.
(NOTE: - Electromagnetic radiation can be expressed in terms of energy, wavelength, or frequency. This document focuses on “wavelength” as a descriptive term as it best references our use of light related to forensic contrast lighting and forensic contest photography.)
- A meter is unit of length.
- A meter is equal to the distance of 3.2808399 feet.
- A meter is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second.
- One meter is the same as 1 billion (1,000,000,000) nanometers
- to take in or soak up.
- the act of absorbing light
- the state or process of light being absorbed
- to move in one direction, hit a surface, and then quickly move in a different and usually opposite direction.
- to cast back (light, heat, sound, etc.) from a surface.
- light reflecting off of a smooth surface.
- light reflecting off of a rough surface.
- shine or glow brightly due to fluorescence.
- to produce, undergo, or exhibit fluorescence.
- is the emission of light by a substance that has absorbed light or other electromagnetic radiation.
- objects that generate their own light such a candle or the sun.
- objects that are capable of reflecting light such as the moon.
- the creation/emission of light by any one of many processes that do not involve heat that include Chemiluminescence and Fluorescence.
- the emission of light during a chemical reaction that does not produce significant quantities of heat. Example: Spray Luminol on blood.
- a combination of fluorescence and phosphorescence
- mass-less particles containing various amounts of energy that travel in a wave-like patterns shown as waves and known as wavelengths. Ultraviolet radiation has a shorter wavelength, a higher frequency and higher energy then Infrared radiation. Infrared radiation has a longer wavelength, a lower frequency and lower energy than Ultraviolet radiation.
| Metric Unit | Exponential |
| Yottameter | 1,000,000,000,000,000,000,000,000 1024 |
| Ettameter | 1,000,000,000,000,000,000,000 1021 |
| Wexameter | 1,000,000,000,000,000,000 1018 |
| Petameter | 1,000,000,000,000,000 1015 |
| Terameter | 1,000,000,000,000 1012 |
| Gigameter | 1,000,000,000 109 |
| Megameter | 1,000,000 106 |
| Kilometer | 1,000 103 |
| Hectometer | 100 102 |
| Decameter | 10 101 |
| ONE METER | 1 100 (One meter is equal to the distance of 3.2808399 feet.) |
| Decimeter | 0.1 10¯1 |
| Centimeter | 0.01 10¯2 |
| Millimeter | 0.001 10¯3 |
| Micrometer | 0.000,001 10¯6 |
| Nanometer | 0.000,000,001 10¯9 |
| Picometer | 0.000,000,000,001 10¯12 |
| Femtometer | 0.000,000,000,000,001 10¯15 |
| Attometer | 0.000,000,000,000,000,001 10¯18 |
| Zeptometer | 0.000,000,000,000,000,000,001 10¯21 |
| Yoctometer | 0.000,000,000,000,000,000,000,001 10¯24 |
| 1 Meter | 1 (one) Meter - (One meter is equal to the distance of 3.2808399 feet.) |
| 1 Meter | 10 (Ten) Decimeters |
| 1 Meter | 100 (Hundred) Centimeters |
| 1 Meter | 1,000 (Thousand) Millimeters |
| 1 Meter | 1,000,000 (Million) Micrometers |
| 1 Meter | 1,000,000,000 (Billion) Nanometers |
- one inch is equal to 25,400,000 nanometers
- one nanometer is equal to 0.000,000,039 inches