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Page 1: Introduction to Forensic Photography

• Introduction to the discipline of forensic photography as presented by West Virginia University.

• Reference: Robinson, 3rd edition, Crime Scene Photography.

Page 2: What is Photography?

• Definition and overview of photography.

• Originating from West Virginia University's Department of Forensic and Investigative Science.

Page 3: Arranging the Scene

• Proper arrangement of elements in the scene is essential for achieving photographic objectives.

• Important aspects of successful photography include:

  • Lighting: Managing light to enhance visibility.

  • Color: Utilizing colors to convey mood and context.

  • Subject Composition: Organizing subjects in the frame for clarity and relevance.

Page 4: Exposure Stops

• Proper exposure:

  1. Preserves details in the image.

  2. Achieves the photographer's objectives.

• Exposure differences expressed as "stops":

  • +1 Stop: Doubles the light.

  • -1 Stop: Halves the light.

Page 5: Exposure Variables

• Key variables affecting exposure include:

  • f/stop: Controls the aperture size.

  • Shutter speed: Determines duration for which light hits the sensor.

  • ISO: Not a direct exposure variable, but crucial in photography.

• Light can be natural or artificial, impacting exposure.

Page 6: Digital Single Lens Reflex (DSLR) Camera Components

• Components of a DSLR camera:

  1. Viewfinder (eyepiece lens)

  2. Pentaprism

  3. Condenser lens

  4. Focusing screen

  5. Color and infrared filter

  6. Digital sensor

  7. Shutter

  8. Display

  9. Electronics

  10. Autofocus system

  11. Reflex and relay mirror

  12. Focusing elements

  13. Aperture

  14. Zoom elements

  15. Front light gathering elements

  16. Batteries.

Page 7: Shutter Speeds

• Types of shutters: Mechanical shutter and others.

• Shutter speeds expressed in seconds or fractions of seconds:

  • Faster shutter speeds: Allow less light.

  • Slower shutter speeds: Allow more light.

Page 8: f/stops (Aperture)

• Aperture control:

  • Wide aperture: Larger opening, more light.

  • Narrow aperture: Smaller opening, less light.

Page 9: ISO (International Organization for Standardization)

• ISO Definition: Signal gain or amplification.

• Noise Issue: Higher ISO can increase noise.

• Base ISO: Provides optimal signal-to-noise ratio.

• ISO Guidelines:

  • Higher ISO = Increased brightness.

  • Lower ISO = Decreased brightness; advisable to keep low for quality photographs.

Page 10: Reflective Light Meter

• A reflective light meter assists in determining exposure, used as a guide.

• 18% Grey Card: Reflects 18% of the light and serves as a middle reference point.

• Adjustments may be required based on subject color:

  • White subject: Overexpose purposefully.

  • Dark subject: Underexpose purposefully.

Page 11: Angles of View

• Focal length impacts the angle of view:

  • Greater focal length (e.g., 50mm → 100mm): Decreased angle of view.

  • Smaller focal length (e.g., 100mm → 50mm): Increased angle of view.

Page 12: True Macro Lenses

• Designed for close-up photography with optimal results:

  • Benefits include sharp edges and 1:1 ratio for lifesize image recording on the digital sensor.

Page 13: Cardinal Rule #1: Fill the Frame

• Importance of getting closer to the primary subject for:

  • Increased resolution.

  • Elimination of irrelevant elements in the photograph.

Page 14: Depth of Field (DOF)

• Defined as the range from foreground to background in sharp focus.

• Depth of Field Variables:

  • Wider aperture = Increased DOF.

  • Narrower aperture = Decreased DOF.

Page 15: Cardinal Rule #3: Keep the Digital Sensor Parallel

• Ensuring correct composition by keeping the sensor parallel to the scene is critical:

  • Incorrect composition occurs when the sensor is angled, leading to poor framing.

  • Correct composition maintains focus on evidence while eliminating distracting backgrounds.

Page 16: Exterior Overall Photographs

• Capturing the scene from a standing perspective includes:

  • General surroundings and reference points (e.g., street signs).

  • Entire 360-degree view of the structure.

  • Noting the structure's name/address, entry/exit points, and nearby vehicles.

Page 17: Interior Overall - Crime Scene

• Capturing a comprehensive view of the interior:

  • Pathway leading to the scene.

  • 360-degree view for thorough documentation.

Page 18: West Virginia University

• A reference point without additional detail.

Page 19: Close-Up Photographs

• Guidelines for effective close-up photography:

  • “As found” images: Show the scene without alterations or labels.

  • Include labels and scales when necessary (e.g., evidence marker A).

  • Scale is important for context in forensic photography.

Page 20: Roadmapping

• Photographic technique for documenting bloodstained surfaces:

  • Perform different types of shots: overall, mid-range, and close-ups.

  • Group photographs are essential.

• Steps in roadmapping include:

  1. Provide scales in at least 2 dimensions on each plane.

  2. Label major stain or pattern groups (e.g., A, B, C).

  3. Assign individual IDs to “unique” stains (e.g., A1).

  4. Use tape or arrows to show motions or Areas of Concern (AOCs).