Police Photography Flashcards
coined the word photography when he first wrote a letter to henry fox talbot
Sir john F. W. herschel
the application of the principles of photography is relation to the police work and in the administration of justice
police photography
the mechanical and chemical result of photography.
photography
refers to all kinds of formed image
picture
an image that can only be a product of photography
photograph
Uses of photoraphy
personal identification for communication for record purposes for preservation for discovering and proving for court exhibits crime prevention police training reproducing and copying
personal identification
considered to be the first application of photography in police work
the first police who utilized photography in police work as a supplementary identification in his anthropometry system
Alphonse Bertillion
considered to be the utmost used of photography in police work
record purposes
different views in photographing
general view
medium view
close up view
extreme close up view
taking an over-all view of the scene of the crime. it shows direction and location of the crime scene
general view
the taking of the photograph of the scene of the crime by dividing it into section. this view will best view the nature of the crime
medium view
the talking of individual photograph of the evidence at the scene of the crime. it is design to show the details of the crime
close-up view
commonly designed in laboratory photographing using some magnification such as photomacrography and photomicrography
extreme close-up view
taking a magnified (enlarged) photograph of small object through attaching a camera to the ocular of a compound microscope so as to show a minute details of the physical evidence
photomicrography
taking a magnified (enlarged) photograph of small object by attaching an extended tube lens (macro lens) to the camera
photomacrography
the pricess of reducing into a small strips of film a scenario. it is first used in filmaking
microphotography
used synonymously with phoyomacrography
macrophotography
the process of taking photograph of a far object with the aid of a long focus and telephoto lens
telephotography
evidence presented in court once accepted became known as ________
Exhibit
Exhibit 1, 2, 3 etc for the defense
Exhibit A, B, C etc for the prosecution
Essesentials of photgraphy
light camera lens sensitized material chemical process
an electromagnetic energy that travels in a form of wave
light
speed of light
186,000 miles per second
a light tight box designed to block unwanted or unnecessary light from reaching the sensitized material
camera
the light gathering mechanism of the camera from the object to form the image
lens
composed of a highly sensitized chemical compound which is capable of being transformd into and image through the action of light and with some chemical processes. (film and photo paper)
sensitized material
The process necessary for reducing silver halides into form so as a latent image and a positive image be made resulting to what we called photograph
Chemical process
Theories of light
The wave theory (hyugens)
Corpuscular theory (newton)
Modified wave theory (maxwell and hertz)
The theory that transcribed from the motion of the water that if we observe a piece of log floating in the ocean and with the force of the air would naturally will make the log move up and down
The wave theory (hyugen)
This later opposed the wave theory stating that light has its effect by the motion of very small particles such as electrons
Corpuscular theory (newton)
Based on electromagnetics. All the theories are still considered to be of little lacking that law enforcement need not to be very focus on this but rather go along with the accepted conclusion that light is form of energy, which is electromagnetic in force
Modified wave thoery (maxwell and hertz)
The distance measured between two (2) succesive crest or through of wave and it is expressed in either millimicron (nanometer) or angstrom
Light wavelength
It is the units of light wavelength which is equivalent to one-millionth part of a millimeter
Millimicron
It has an equivalent measurement of ten (10) millionth part of a millimeter
Angstrom
Once light hits a certain medium its action can be characterized as ___________, ____________ and ___________
Reflected, transmitted and absorbed (RAT)
Once the light hits a mirror and it bounce back
Reflected
When the light hits a transparent glass which would allow the light to pass through its medium
Transmitted
When the light hits a dark color object and prevents it from either bouncing or passing through
Absorbed
He proved that the light which man see as white light is actually a mixture of all colors of the spectrum this is produced when we allow light to hit a glass prism (sharp edge of the glass) a rainbow array will then be shown with colors (from top to bottom)
Isaac newton
The visible light is also said of a wavelength of a wavelength of between ______________________
400 - 700 millimicron or nanometer
Types of light
Visible light - is the type of light that produces different sensation when reach the human eye. It is the type of light, which is capable of exciting the retina of the human eye
Invisible light - lights in whicn their wavelength are either too short or too long to excite the retina of the human eye i.e. x-ray, infra-red, ultra-violet lights
Photographic rays
X-ray
Ultra-violet ray (before the violet)
Visible light
Infra-red (beyong the red)
Light with the wavelength between 0.1 to 30 millimicrons. It is produced by passing an electric current through a special type of vacuum tube.
This type of light works in the principles of shadow photography
X-ray
Who incidentally discovered x-ray
Conrad welhelm roentgen
Radiation having the wavelength of 30 to 400 nanometers designed to photograph fingerprints in multi-colored background, documents that are altered, decipherment of erased writing and developing invisible writing. It is commercially known as “black light”
Ultra-violet ray
It refers to type of radiation having a wavelength of 400 to 700 millimicrons designed for ordinary photographing purposes
Visible light
Considered as the photographic ray with the longest wavelength ranging from 700 to 1000 millimicrons. It is designed to take photograph of over written documents, obliterated and charred documents or for black out photography.
Infra-red
It is sometimes referred to as “heat rays”
Infra-red
Light sources
Natural light
Artificial light
Are those light which come to existence without the intervention of a man e.i. Sunlight, moonlight and starlight
Natural light
Object in an open space casts a deep and uniform shadow and the object appears glossy
Bright sunlight
Object in an open space casts a transparent or bluish shadow. This is due to thin clouds that covers the sun
Hazy sunlight
Object in an open space casts mo shadow due to thick clouds covering the sun
Dull sunlight
Otherwise known as man-made light
Artificial light
Continuous radiation
Photoflood lamp Fluorescent lamp Incandescent bulb Ultra-violet lamp Infra-red lamp
Otherwise known as reflectorized light or spot light. It is a light with a reflector at the back which focus the light to the object the common wattages of this lamp is 500 watts
Photoflood lamp
Are tube lamps in which the walls are coated with fluorescent powders with both ends is mounted with a holder that serves as the reflector. This is commonly used by everybody more than it is used in photographing
Fluorescent lamp
Short duration type
Flash bulb
Electronic flash
Chemical lamps, as it generates lgight by the rapid combination of the metal in oxygen. The bulb can be used only once as the bulb is busted when fired electrically. There are thin flaments inside the bulb with two electrical contacts. When the current flows through the filaments it becomes incandescent and ignites the explosive primer that ignites the aluminum foil that burns, givng flash of tense light
Flash bulb
Bulb with a wire flament connecting two wires which contains the electrical charge that produces the light. Everybody likewise commonly uses this although it is more expensive in terms of electrical consumption
Incandescent bulb
Produces by an instantaneous electrical in charges between two electrodes in a gas filled glass bulb. The electrical energy for the dicharge is kept in capacitor or condenser it usually ranges from 1/300 second and 1/500
Electronic flash