FP

Light

is electromagnetic radiation within a certain portionof the electromagnetic spectrum.

visible Light

is usually defined as having wavelengths in the range of 400 - 700nanometer (nm), or 4.00 x 10-7 to 7.00 x 10-7 m, between the infrared (withlonger wavelengths) and the ultraviolet (with shorter wavelengths). Thiswavelength means a frequency range of roughly 430 - 750 terahertz (THz)

299,792,458

METERS OF SPEED OF LIGHT

186,281

MILES SPEED OF LIGHT

optics

The science behind how the human eye works. • The study of light and the interaction of light and matter. The observation andstudy of optical phenomena such rainbows and the aurora borealis offer manyclues as to the nature of ligh

spectrum

COLOR OF THE LIGHT THAT IS SEPARATED IS CALLED e

violet rays

bent the most.

red rays

bent the least

ELECTRO MAGNETIC SPECTRUM

the light is bent and because somewavelengths bend more than other,the colors are separated.

visible light

Is a small part of the electromagnetic spectrum where the visible light isfound, the portion of the electromagnetic spectrum that affect the humansense of sigh

primary colors

• White light can be made by mixing

red green blue

what are the primary colors

addition

The process of making colors bymixing primary colors is called

secondary colors

Colors made by combining twoprimary colors.

secondary colors

yellow magenta cyan

color temperature

Refers to the measurement of the color characteristics of a light source,expressed in degrees Kelvin (K). This measurement indicates whether the lightappears warm (reddish) or cool (bluish), significantly influencing the mood andatmosphere of photographs.

mood and emotion

different color temperatures can evoke various feelings. Warm colors (like those from sunrise or sunset) create a sense of comfort andintimacy, while cool colors convey calmness and serenity.

white balance

Photographers adjust their camera settings or post-processingtechniques to achieve accurate color representation. Setting the correct whitebalance helps prevent unnatural color casts in images. For instance, using alower Kelvin setting for portraits can enhance skin tones, while a higher settingcan make landscapes appear more vibrant.

natural light

the source of all daylight is the sun. The combination of colorand contrast ascertains the equality of the daylight. Ex: Sun, stars, lightning, fire,Aurora Borealis

bright sunlight

the subject will producestrong shadows because the source of light isnot covered and the objects or subjectsappear glossy in open space due to directsunlight and reflected light coming from thesky which act as a reflector.

hazy sunlight

the sun is covered by thinclouds and the shadow appears bluishbecause of the decrease of light falling on thesubject in open space. The shadow cast istransparent to the eye and more details arevisible under this lighting condition than abright sunlight

dull sunlight

the sun is totallycovered by thi c k c louds. Noshadow is cast to the uniformillumination of lights all around thesubjects in open space.

artificial light

almost all artificial light sources can be used in photographingof objects, as long as the light is capable of exposing the sensitized materials. Some of the artificial lights are electro flash, photoflood lamp, fluorescent lamp,infrared lamp, and ultraviolet lamp

transparent objects

These are mediums that merely slow down the speed of light but allow to passfreely in other respects, transmit 90% or more of the incident light.

translucent objects

These are mediums that allow light to pass through it in such a way that theoutline of the source of light is not clearly visible, transmit 50% or less of theincident light

opaque objects

A medium that can divert or absorb light, but does not allow light to passthrough, they absorb most of the light while reflecting some of it.

reflection of light

refers to the rebounding or deflection of light. The angle ofreflection depends upon the angle of the light striking the material, which isreferred to as the angle of incidence.

absorption of light

When light strikes a medium and is neither reflected nor transmitted, it is said

transparent

When objects can be clearly seen through the medium, themedium is

INDEX OF REFRACTION

The speed of light in each transparent substance is called the

dispersion of light

is a phenomenon that occurs when light waves travelthrough different media and separate into their constituent colors

refraction

is the bending of light rayswhen passing through a surfacebetween one transparent materialand another.

alphonse bertillon

He initiate anthropometric measurementsofpersonal identification

forensic photography

The art or science of photographicallydocumenting a crime scene andevidenceforlaboratory examination and analysis forpurposesof court trial.

T. Odelbercht

First advocated the use of photography for theidentificationof criminals and documentation of evidence andcrimescenes

Micro Photography

Is the art or process of photographing minute objects and magnified by means of the microscope and enlarge from 10 times up

Ultra Violet Photography

Is the art or process of photographing unseen objects by the naked eye with the use of ultra

Mug Shot Photography

It is usually use for personal identification which is the first use of photography in police work.

Evidence Photography

Many valuable articles of evidence can be found at the crime scene. Each o b j e c t c a n b e p h o t o g r a p h e d individually and in relation to other objects at the scene.

Police Photography

It is an art or science which deals with the studyof theprinciples of photography, the reproduction of photographicevidence, and its application to police work.

picture

It is a generic term referring to all kinds of formedimaged.Itisa representation made by various means suchaspainting,drawing or photography

photograph

A mechanical and chemical result of photography.

forensic

Derived from the Latin word “Forum” whichmeansamarketplace where people gather for public discussion.Itissometimes used interchangeably with the wordlegal.

photography

Art and science of reproducing an image by meansofLightthrough some sensitized material with the aidof acamera,lens and its accessories, and the chemical processrequiredinorder to produce a photograph.

sensitized material

Refers to films and papers that are composed of emulsion containingsilverhalide crystals suspended in gelatin and coated on a transparent or reflectivesupport.

film

Consists basi cal l y of a random scattering of light sensitive silver halides suspended in a layer of animal gelatin which is coated onto acetate support or base.

protective coating

The top layer of the film protects the fragile emulsion fromhumanhands.There is always an oily substance on skin that, if transferred to the emulsion, wouldeffectively ruin the film. The protective coating also protects the emulsionfromminor scratches and abrasions. The protective coating washes awayduringfilmprocessing.

emulsion

true "heart" of film. It is the part of the filmthat recordstheimage by physically reacting to light that reflects fromthescenebeingphotographed, passes through the camera's lens and strikes the film.

film base

The base, the thickest of the layers, supports the other layers

anti halation backing

The bottom layer of a sheet of film is very dark-colored material that prevents halation.

green filter

a layer that is orthochromatic. This is the layer sensitivetobluelight and green, but no to red light pass on to the bottomof theemulsionlayer.

red filter

– a panchromatic layer sensitive to blue and red.

fast films

contains numerous numbers of large grains of silver halidesthatusually develop in groups; film that are very sensitive to light. Whentheavailable light is dim, this type of film is best because of thelowreflectionpower of the subject against a background. It is lowcontrast, buthighinbrightness; has grainy result.

slow films

film that requires l o n g e r p e r i o d o f t i m e t o completely expose their emulsion to light; film with fine grains of silver halides.

film speed

an emulsion's degree of sensitivity to light and determinestheamount of exposure required to photograph a subject given lightingconditions.The manufacturer of the film assigns a standardized numerical ratinginwhichhigh numbers correspond to "fast" emulsions and low numbers to"slowones".

Fast speed films

ISO 200/24

Low speed films

ISO 25/15 to ISO 100/21

Medium speed films

ISO 125/22 to ISO 200/24

Superfast films

ISO 400/27

Spectral Sensitivity

– responsiveness of the filmemulsion tothedifferentwavelengths of light sources

. Ultra-violet sensitive filmy

– sensitive to UV rays only

a. Blue sensitive film –

a film specially treated that makes it moresensitivetoblue rays of light

Monochromatic Film –

film that is sensitive to a single color of light (forblackand white)

panchromatic film

– sensitive to ultra-violet rays and all light foundinthevisiblespectrum, especially to blue and violet light. It is suitable for general useinthepreparation of black and white photography because it produces themost naturalrecording of colors.

Process Panchromatic film

– permit short exposure under average lightingconditionand has the advantage of fine grain structure.

Orthochromatic Film –

film that is sensitive to UVrays, blueandgreen colors, but not to red. Red portions are recordedas darktones,while green and blue parts appear as light tones whenprinted. Thisispopular in the market as Kodalith Film.

infrared film

a special type of film that is sensitivetoinfraredandultra-violet radiation. It is also sensitive to all the colors foundinthevisible spectrum. IR film is useful in penetrating hazebecauseofitslonger wavelength.

iso 100-200

– for general purpose.

photographic paper

The result of photography in its final form is the photograph. One material is necessary to produce a photograph or positive print. It has emulsionthat that is coated with opaque material like paperOne material is necessary

Baryta layer –

a gelatin containing Baryta crystals to increasethereflectivityof the paper.

base

– made of hardened white paper, which must be chemicallypuretoensure that it will not interfere with the chemical processes towhichtheemulsion is subjected

Silver Chloride Paper

– contains silver chloride emulsion; grainedandproducedeep black images; used for contact printing. Its sensitivity tolightislow.Generally, the size of the positive print is the same as the size of thenegativeused and usually it will give blue-black tone if properly developed.

Silver Bromide Paper –

contains silver bromide emulsion. Light sensitivityofthis type is faster than the silver chloride paper. The photographic paperisusedfor projection printing or enlarging process wherein the negativeimageisprojected or enlarged. If properly developed, the silver bromide paper will giveablack tone.

Silver Chlorobromide Paper –

contains a combination of silver chlorideemulsion; its emulsion speed lies between that of chloride and bromidepapers;used both for contact and projection printing. The sensitivity of this paperiseitherslow or fast. The slow emulsion is used for contact printing whilethefastemulsion is used for projection printing.

Low contrast –

usually suitable to a very high contrast negativetoproduceanormal print or photograph.

High/Hard Contrast –

. suitable to a very low contrast negative tocompensatefor lack of brilliance and produce a normal print or photograph.

white

are preferred for cold effect.

cream

– are preferred for pictorial effect, portraits, landscapesorwhenwarmth effect is desired

buff papers

preferred for tone prints.

glossy paper

- preferred where fine detail and brilliant images arerequired

Semi-matte papers

– are with decided textures which obscurefinedetails

rough paper

used for large prints or where breadth rather thandetailisnecessary.