FORENSIC PHOTOGRAPHY 2 Flashcards
is a radiant electromagnetic energy that can be seen by the naked eye. It excites the retina of the eye and makes things visible.
Light
those that can be detected by our naked eye
Visible –
these are the radiations, which are either too short or too long in wavelength to excite the retina of the eye.
Invisible
This refers to the speed of light as it travels. (Usually light travels 186, 000 miles per second)
The Velocity of travel
This is the distance between two successive crests since light travels in wave motion.
The Wavelengths
This refers to the quantity or the number of waves that light creates as it travels.
The Frequency or the number of vibration of the wavelength
Refers to rays having a wavelength of 1 to 30 millimicrons. Hallow solid objects as seen by the naked eyes can be penetrated by x – rays. This is being used to produce shadow photogtaphs of internal structures of solid objects.
X – Ray Radiation
It is a ray having a wavelength of 30 to 40 millimicrons. These rays give up energy in the form of visible light that gives “fluorescent effect” to the object. It can be use in photographing fingerprints on multi – colored backgrounds, in documents that are altered chemically as well as in the detection of secret writings.
Ultra Violet Rays (UV)
It is otherwise known as “black light”.
Ultra Violet Rays (UV)
The wavelength of visible light is from how many miliimicrons which produces white light.
400 to 700 millimicrons,
Isaac Newton in 1666, state that the light which man sees as white is actually a mixture of all colors of the spectrum. He discovered this, when a beam of light passed through a glass prism and produces the rainbow array of hues of the visible spectrum. With this, we can say that white light means presence of all colors of light, and black means absence of all of colors light.
in 1666, state that the light which man sees as white is actually a mixture of all colors of the spectrum. He discovered this, when a beam of light passed through a glass prism and produces the rainbow array of hues of the visible spectrum. With this, we can say that white light means presence of all colors of light, and black means absence of all of colors light.
Isaac Newton
is actually a mixture of seven colors, namely red, orange, yellow, green, blue, indigo, and violet.
White light
with 400 to 500 millimicrons, it has the shortest wavelength
Blue –
with 500 to 600 millimicrons, it has a medium wavelength
green –
with 600 to 700 millimicrons, it has the longest wavelength
red
A combination of blue and green colors
Cyan
A combination of green and red colors
Yellow
A combination of red and blue colors
Magenta
It is a ray having a wavelength of 700 to 100 millimicrons. means below the red. Even though our eyes cannot see the IR, we have a sensor for it, “our skin”.
Infra red Rays (IR)
comes to the existence without the intervention of man,
Natural
It usually refers to daylight.
Natural Lights
is considered as the source of all daylight. Daylight can be classified according to their intensity.
Sun
simply means the amount or the quantity of light that are present in a scene.
Intensity
Objects in open space, cast a deep, strong and uniform shadow.
Bright Sunlight
Object in open space cast a transparent shadow. In hazy sunlight, the clouds partially cover the sun.
hazy Sunlight
Objects in open space cast no shadow. At this time, the sun is totally covered by the clouds.
Dull Sunlight
Almost all ——– light sources are possible to be used in photographing an object. But most preferred those lights that are incandescent.
Artificial Light
means, light are produced by means of heat. In photography, incandescent is usually known as ——
Incandescent
tungsten light.
It is also known as reflectorized light or spot light. This lamp used reflector to focus the light, to the object being photographed.
b. Flash Bulb
photoflood Lamp
These are chemical lamps for they generated light through the rapid combustion of metal in oxygen. can be ignited by means of a flashgun and can only be used once as the is busted when fired electrically.
Flash Bulb
These are tube lamps wherein the walls are coated with materials that are capable of fluorescence. These are commonly used by anybody but not merely in photography for the light it produces are not incandescent.
Fluorescent Light
It is a special type of lamp that is capable of producing infra- red radiation. This type of bulb is useful in photographing object at dark places.
Infra – Red Lamp
Produces light by instantaneous electrical discharge between two electrodes in a glass filled glass bulb.It has the capability to arrest or stopped objects, or subjects in fast motion.
Electronic flash
It is a gas lamp burning disulfide vapor in oxygen or in nitric oxide. Its bulb is made up of a glass transparent to ultra violet light, and such bulb is common to all people as “black light”.
Ultra Violet Lamp
light rays are the one that affects the eyes. The object is seen as white when all of the various wavelength of the visible light are reflected.
Reflected -
– when there was no reflection from the subject and all of the various wavelength of the visible rays are absorbed, this will produce black, which means absence of all colors.
Absorbed
– when the rays of light pass through a transparent material, such rays will be transmitted on the other side.
Transmitted
is the process of bending the rays of light as it strikes a transparent material. Best example of this is when rays of light passed through the water.
Refraction
on the other hand occurs when the rays of light reach an opaque material. This usually happens when a light strikes the sharp edges of a knife.
Diffraction
There are two kinds of sensitized material
Film
Photographic paper
that produces the negative after chemical development and the
the Film