Aberrations - ANSWER Image formed by a lens is blurred or distorted generally at
the widest aperture.
Focal Length - ANSWER Distance in "nm" optical center of a lens and sensor
when camera focused on infinity.
Telephoto Lens - ANSWER Compresses the distance between the foreground and
the background.
What is the "Shutter" - ANSWER Opening/ close to control the amount of light
striking the camera lens.
SWGIT - ANSWER Scientific Working Group on Imaging Technology
SWGFAST - ANSWER Scientific Working Group on Friction Ridge Analysis, Study
and Technology
Overcast ( no shadows) Day - ANSWER F/8
ISO 100
1/125 SS
,or
F/11
ISO 100
1/60 SS
is better due to DOF
What is "ISO" - ANSWER Sensors relative Sensitivity to light
ISO 100 - Sensitive to light
ISO 3200 - Requires less light.
Larger ISO - grainier and noise
4 Variables that directly affect Exposure - ANSWER Shutter Speed
Apertures
ISO
Ambient Lighting
Rule of Thirds - ANSWER DOF extends 1/3 in front of the point of exact focus and
2/3 behind the point of exact focus
Luminescence - ANSWER Ability of a molecule to emit light from a cause other
than heat. Phosphorescence and Fluorescence
RUVIS - ANSWER Reflected Ultraviolet Imaging System, uses short wave
ultraviolet light to visualize untreated fingerprints
Absorbed ultraviolet light - ANSWER Blood will absorb UV light, making it contrast
with surfaces similar in color to blood.
Visible light fluorescence - ANSWER Powders, chemicals, non-blood body fluids,
fibers and drug residue
Sync Speed - ANSWER Shutter speed at which cameras should be set when an
electronic flash is used
Each camera has one particular shutter speed that is designed as its sync speed
Avoid fast shutter speeds, shutter closes when flash is on
Image Stabilization - ANSWER Also known as vibration reduction lens elements or
sensors can move gyroscopically when movement is detected, allows use of shutter
speed 2 stops slower than normal
Hyperfocal Focus - ANSWER Infinity is in the background
maximizes DOF
,What lens doesn't cause distortion - ANSWER 50 mm Lens
Photographing Fluorescent evidence - ANSWER Proper exposure is frequently -2 (
two stops less)
Photographing Fluorescence in visible light range - ANSWER F/11
ISO 100
aperture priority
Photogrammetry refers to: - ANSWER Photographing an object
measuring the image of the object on the processed photograph
reducing the measurements to some form such as a topographic map or scale crime
scene diagram
Proper Exposure Triangle - ANSWER F/Stop (Apature) ISO
\ flash/ambient light /
\/
Shutter Speed
F/Stop - ANSWER Refers to aperture, represents fraction of focal length of lens
over diameter of diaphragm.
*** like gauged wire big number = small and vice versa
Focal Length multiplier - ANSWER Corrects "cropped" field of view in camera
where sensor is smaller than the original film negatives for that size
Sunny Day Rule F/16 - ANSWER Sunny day with hard shadows selects F/16 and
shutter speed faster than your ISO
Beware of Diffraction- light bending when it strikes the edge, issue with small apature
Focal Length - ANSWER Distance from optical center of lens to camera sensor
plan when camera is focused on infinity
3 problems with camera lenses - ANSWER 1. Aberrations- different colors refract
differently
2. Diffraction-bending of lights, loss of resolution
3. Distortion- the photo doesn't look as it seems
7 camera variables for taking photographs - ANSWER ISO
Shutter Speed
Aperture
Flash Mode
Focal Length
Hyperfocal focus - ANSWER Maximizes DOF range for larger outdoor crime
scenes
Method to focus with infinity is in view, align the infinity symbol with the appropriate
F/Stop on DOF scale
Zone Focusing - ANSWER Rear distance of area that needs to be in focus (zone)
is used on DOF scale with proper exposure
Helps maximize DOF for smaller scenes
3 factors that affect DOF - ANSWER F/Stop
Lens Choice
Camera to subject distance
What is depth of field and Aperture - ANSWER "Stops" are either halved or
doubled, changes to the aperture ( one stop up is 2X the light, one stop down is half
the light)
What is Depth of Field - ANSWER Range of items that will be focused in the
foreground and background
-variable range from foreground to background of what appears to be in focus
What is Aperture - ANSWER Wide aperture:
focus on front = clear back is blurry
focus on the back = clear front is blurry
Small aperture
entire range is in focus
Dynamic Range - ANSWER The ability of the camera to capture extreme range of
shadows and highlights
Exposure latitude/ high dynamic range - ANSWER Ability to capture extremes of
highlighting/shadows; ability to correct exposure issues post-processing
Inverse square law - ANSWER As light travels twice the distance the intensity is
quartered
[2(distance)=1/4 intensity
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