# Shared Flashcard Set

## Details

FRSC 513 Final
Final Exam Flashcards for Forensic Photography
98
Criminology
07/16/2019

Term
 When do you want to use a flash?
Definition
 When there is not enough light: early morning, late afternoon, night, indoors; when the right quality of light is needed to eliminate tints
Term
 What is the guide number?
Definition
 It is the designation for the flash unit's relative output power.
Term
 What is the standard flash's GN number?
Definition
 120
Term
 When using a flash what should your shutter speed be?
Definition
 Whatever the sync speed of the camera is
Term
 What is the equation for the f/stop?
Definition
 GN/Distance = f/stop
Term
 What is the GN for the built in flash?
Definition
 36
Term
 Why don't we use the built in flash?
Definition
 The GN number is really small, which requires a wide aperture and has a super limited DOF, creates hotspots, and red eye
Term
 What is the sync speed?
Definition
 The speed of which the shutter is open while the flash fires
Term
 What happens if you use a shutter speed faster than the sync speed?
Definition
 The shutter will be in the picture
Term
 What happens if you use a shutter speed slower than the sync speed?
Definition
 Usually nothing, but if very slow it may cause blurred images and or ghost images
Term
 What are the flash stop increments and what are these 1 stop increments called?
Definition
 1, 1/2, 1/4, 1/8, 1/16, Vari-Powers
Term
 How do you decrease the amount of light when using a flash?
Definition
 use vari-stops, move away from subject
Term
 How do you increase the amount of light with a flash?
Definition
 Move closer, open the aperture
Term
 What is a normal room for flash?
Definition
 “Normal” 10’ by 12’, light color walls, with 8’ or 9’ ceilings
Term
 What are non-normal rooms?
Definition
 smaller than normal, larger than normal, outside, dark colored walls, and reflective surfaces
Term
 What is a hot shoe?
Definition
 It is the mount on the camera for the flash
Term
 Rule of Thumb: When you are 5’ or closer to your subject, remove the flash from the hot-shoe, so it can accurately be aimed at your target. Why?
Definition
 To removed hot spots, red eye, and the flash is above the subject that close
Term
 What allows the flash to be off camera and still work?
Definition
 PC / Remote Cord
Term
 When using a PC / Remote cord, how far should it be from the subject and why?
Definition
 at least 2 feet to avoid over exposure
Term
 What is red eye in photography?
Definition
 It is the reflection of the blood vessels in the back of the eye.
Term
 How do you fix red eye?
Definition
 Keep the flash off the direct axis
Term
 How must the flash be oriented?
Definition
 In the same manner as the subject (vertical vs horizontal). Think FTF
Term
 True or False: Flash and Camera must be oriented correctly in the horizontal of vertical manner of the subject.
Definition
 True
Term
 True or False: Flash heads must be set to the focal length of the lens (wide/norm/telephoto)
Definition
 True
Term
 What does the flash diffuser do?
Definition
 Diminishes light and Diminishes Glare
Term
 What are the ways to achieve a -1 stop with a flash without changing any camera settings?
Definition
 Place one finger in the cent of the flash or put one handkerchief over the lens
Term
 Explain the inverse squared law.
Definition
 As distance doubles, light is quartered; 2D=I/4
Term
 What is the result of the inverse squared law?
Definition
 f/stops
Term
 How does automatic flash work?
Definition
 Relies on reflected light (18%) being sensed by the flash sensor eye and the sensor will cut off light duration to prevent overexposure
Term
 What are the advantages of automatic flash?
Definition
 Save battery, less recovery time in between flashes, uses flash ranges
Term
 In regards to flash, what does TTL stand for and mean?
Definition
 Through The Lens (TTL) means the flash is being controlled by the camera body's sensor
Term
 When is fill flash used?
Definition
 In a scene with strong ambient light and shadows
Term
 When performing the fill flash technique, where do you meter and then aim the flash?
Definition
 Meter in the bright area, but aim the flash where it is most needed. Make sure to set the flash -1 stop
Term
 Where is the flash aimed with bounce flash?
Definition
 Midway or closer, but not past the midway point of the light will hit behind the object
Term
 When is oblique lighting used and why?
Definition
 It is used when photographing 3D impression evidence. This creates shadows which show depth to the impression in a photograph
Term
 Why use a remote or timer with a camera?
Definition
 Because the manual depressing of the shutter release can cause camera shake
Term
 What photographs do you take prior to close up photographs?
Definition
 Midrange photographs
Term
 What is the sequence for photographing close up photographs?
Definition
 Establish with location midrange, take one photo as is with no scale, multiple directions and angles with scale,
Term
 True or False: A scale must be on the same plane as the item being photographed?
Definition
 True
Term
 How much of a tire tread must you photograph to get the whole circumference?
Definition
 7.5 feet
Term
 How do you break up the segments tire tread to photograph them for comparison?
Definition
 Split into 1 ½’ segments, overlapping 1”   A = 0” to 19”   B = 18” to 37”   C = 36” to 55”   D = 54” to 73”   E = 72” to 91”
Term
 Why use snow wax in photographing impressions in snow?
Definition
 Creates contrast, allows the cast to set (dental stone gives off heat and will melt the stone)
Term
 What must be included in the photo identifier card?
Definition
 Case Number, Date, Location, Photographer Name, and roll/memory card number
Term
 What information should be included on a labeled scale?
Definition
 Case Number, Item Number, Date, Photographer's initials
Term
 True or False: Anytime one of the variables on the photo identifier card changes, a new photo identifier card needs to be photographed.
Definition
 Ture
Term
 True or False: When scales are used they should be positioned on the same plane as the evidence.
Definition
 True
Term
 Explain the "body panorama" sequence of photographs.
Definition
 Make sure to establish the body with a mid range photograph and then take photos of all four sides and then a frontal picture of the face. Document wounds and when that is done turn over the body and repeat.
Term
 What are two reasons why every photograph should be documented on a photo log?
Definition
 The photo memo sheet can be used to refresh memory at court and it allows the user to document errors in order to prevent future errors.
Term
 Why would you cover up "sensitive" areas of a living body when documenting wounds?
Definition
 It preserves the modesty of the person being photographed as well as those viewing the photos.
Term
 What are the 3 reasons a labelled scale is included in close-up photographs?
Definition
 The scale shows the size of the object/evidence being photographed. The scale allows the examiner to blow up the photo for comparison. The labeling information helps document the image.
Term
 What is the purpose of taking midrange photographs?
Definition
 They establish a special relationship between two objects, usually an item of evidence and a fixed object to show where somethin is in the scene.
Term
 Fully explain what areas do you photograph during exterior overall photographs?
Definition
 Walk the viewer from the outer perimeter in. Take pictures of the cross street, emphasizing the street of the crime, take photos from the sign to the scene. At the scene take outside 360 photos of the building and take a photo of the address sign. Photograph the immediate area and entrances and exits.
Term
 Why is a photo identifier card used?
Definition
 It allows every photograph to be associated back to the photographer and specific crime scene
Term
 When is the best time to log photos on a photo log?
Definition
 Immediately
Term
 When is a labeled scale used?
Definition
 Close-up photographs with scale
Term
 Overall and midrange photographs are taken from what perspective?
Definition
 Natural perspective
Term
 True or False: When taking diagonal photographs of the outside 360 you have to take 360 photographs at each corner.
Definition
 True
Term
 Explain interior overall photographs.
Definition
 Start from the entrance, use a normal lens, photograph corner to corner, floor to ceiling, walk the viewer through the scene using proper orientation.
Term
 What are some issues with taking FPP interior overalls?
Definition
 Hotspots, Non-normal scenes (lots of white walls), reflections, shadows
Term
 What f-stop is optimal for close up photographs and why?
Definition
 F/11 because of diffraction
Term
 Explain the sequence to photograph evidence for close ups.
Definition
 Establish the evidence with a midrange photograph. Take an in situ photo with FTF and FPP, ISO 100. Then take another photograph of the item with scale
Term
 What is an easy way to show that the close-up is an altered close-up?
Definition
 Chane the background
Term
 When taking a midrange of an injury where do you relate it to?
Definition
 To a major joint. Make sure to have proper orientation and form an isosceles triangle
Term
 At the autopsy why is a photo of the sealed bag taken?
Definition
 To document chain of custody
Term
 Define Electromagnetic Spectrum
Definition
 The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation
Term
 What wavelengths are the visible spectrum?
Definition
 400-700nm
Term
 What wavelengths are Infrared?
Definition
 700-1100nm for photography
Term
 What wavelengths are ultraviolet?
Definition
 100-400nm
Term
 Define Fluorescence
Definition
 It is the conversion of light from one state to another, usually light of a longer wavelength and lower intensity
Term
 Define nanometer
Definition
 1billionth of a meter
Term
 How is a wavelength determined?
Definition
 It is the distance between beak to peak
Term
 Provide an example of a short wavelength
Definition
 X-Rays, gamma rays
Term
 Provide an example of long wavelengths.
Definition
Term
 Which is a longer wavelength, UV or IR?
Definition
 IR
Term
 What are the four ways light can react to different surfaces?
Definition
 Reflection, Absorption, Transmission, and Fluorescence. Fluorescence is the conversion of light from one state to another.
Term
 What color will the total reflection of all light be?
Definition
 White
Term
 What color will the total absorption of all light be?
Definition
 Black
Term
 Explain how colors are seen in regards to reflection.
Definition
 White is the total reflection, black is the total absorption, and then the colors you see are the colors reflected back.
Term
 What is transmitted light?
Definition
 Most of the light goes through the surface, but some is absorbed. Think of tinting on a car or a handkerchief on a flash
Term
 Why do we need to wear a filter to see fluorescence?
Definition
 The emitted light is weaker than the original source. Therefore you need to eliminate the overwhelming original source to see the fluorescence
Term
 What color filter is used with a VU light?
Definition
 UV filter or a Yellow Filter
Term
 What color filter is used with a blue light?
Definition
 Orange filter
Term
 What color filter is used with a green light?
Definition
 Red filter
Term
 What nanometers is blue?
Definition
 430-480nm
Term
 What nanometers are shortwave UV?
Definition
 280-315nm
Term
 What is a piece of equipment that uses shortwave UV?
Definition
 RUVIS (Reflected UV Imaging System)
Term
 What wavelength is longwave UV?
Definition
 315-400nm (black light)
Term
 True or False: Shortwave UV (280-315nm / UVB) should not be used on evidence requiring DNA examinations.
Definition
 True
Term
 What type of UV light is considered germicidal?
Definition
 UVC
Term
 What type of UV light is considered tanning UV light?
Definition
 UVA (315-400nm)
Term
 What type of UV light is sun burning light?
Definition
 UVB (280-315nm)
Term
 What wavelength is UVC?
Definition
 Less than 280
Term
 What wavelength is UVB?
Definition
 280-315nm
Term
 What wavelength is UVA?
Definition
 315-400nm
Term
 What are the four applications of IR photography?
Definition
 Visualizing Ink differentiations, Visualizing GSR, Visualizing the writing on burned documents, Visualizing blood stains
Term
 True or False: Bones fluoresce
Definition
 True
Term
 What or the effects of IR light on different substrates?
Definition
 Absorption: Darkens, Reflection: Lightens, Transmission: Disappears, Fluoresces: Longer wavelength with a weaker intensity
Term
 Explain the Stokes Shift.
Definition
 This is fluorescence. Some surfaces will absorb light that strikes them and convert that light to a longer wavelength with less intensity.
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