forensic

• Preserve


  To keep (to preserve)
• Aperture


  • Controls the brightness of the image that passes through the lens and falls on sensor
• Secure


  To secure (the crime scene) in order to keep the exact picture of the crime scene
• Preservation


  The process an investigator must do in order to make the captured image available anytime needed for the investigation
• Authenticity


  • The basic requirement, aside from relevance, for a photograph to be admitted in court as evidence
• Requirements for a photograph to be admissible in court

  • Competent
  • Authenticity
  • Relevant
  • Accurate
• Viewfinder


  • The small rectangular opening found on top of the camera which allows the photographer to compose and frame the shot
• Black and white film

  The best film to use to provide more contrast and details when taking photographs on tools marks evidence for court presentation
• Aside from being authentic, a photograph must also be relevant to be admissible as evidence
• Photographer


  The person who must testify that the photographs accurately portrays the scene as viewed
• Shutter


  • The part of a camera that indicates the timing of the shutter to open and close, sets the length of time in which the lights allowed to enter the camera
• Before a photograph can be introduced as evidence, aside from being properly identified, its accuracy must be shown
• Fast shutter


  The kind of shutter that will produce an image that freezes a moving object to help the investigator visualize its position at any given moment
• Investigators must place evidence markers before taking photographs of the crime scene
• Chemicals used in photography

  • Boric acid, acetic acid- neutralizer
  • Hydroquinone- developing agent
  • Sodium thiosulfate (hyposulfite of soda=hypo) - fixing agent
• When using low-speed film, unless the photographer has an extremely steady hand for slightly longer exposure times, what instrument must be used?
• Faster film speed is used for dimly lit areas and fast-moving subjects
• Three pillars of photography

  • Aperture
  • Shutter speed
  • ISO
• ISO


  Refers to the sensitivity of the camera's sensor
• Three elements used to control exposure

  • ISO
  • F-stop
  • Shutter speed
• Shutter


  Allows the passage of light
• Shutter speed dial


  Controls the speed of the shutter
• Parallax error


  The difference between the viewing system and recorded image
• The common problem using twin lens reflex is parallax error
• The parallax error can be fixed by using an SLR/DSLR camera
• For boxing sports, a higher ASA (more sensitive) film speed is suggested to freeze a moving object
• For boxing sports, a fast shutter speed is suggested to freeze a moving object
• A wide-angle view is needed to show the facade (front) of the house
• A medium view tends to show the four angles of possible entrance and exit points of the suspect
• Crime scene photographs are admissible as evidence in court
• The taking of photographs in a crime scene shall start and end from general to specific
• Purpose of crime scene photography

  Factual replica of the crime
• Photographs in crime investigation

  • Provides enforcers an easier work in court for testimony
• Combination of colors


  Magenta, yellow, cyan, black (the absence of color)
• Transparent


  Allows light to pass through its medium, objects on the opposite side are clearly visible
• Opaque


  Does not allow light to pass through its medium
• Translucent


  Allows light to pass through but not visible, objects are not clearly visible
• Camera type


  SLR and DSLR (the only camera use mirror and prism)
• Filter


  A piece of plastic or glass used to subtract or control light passing through it
• Lens opening (aperture)


  The ratio between the focal length and the diameter of the whole lens expressed in F-number