CRJ 211 : Class Notes Photography
Class Overview
Discussion on upcoming classes and schedule.
Chapters five and six will be covered today.
No class next week due to scheduled exam.
Future classes will include guest speakers focused on photography.
Importance of Photography in Crime Scene Investigation
Photography is a critical skill in scene documentation.
Recommended for aspiring crime scene specialists to take forensic photography classes.
Forensic photography differs in methodology from artistic photography.
Photos serve three main purposes in investigations:
Reconstruction: Helps in reconstructing a crime scene for analysis.
Recall: Assists investigators in recalling details from numerous cases.
Court Evidence: Provides visual evidence for jury members who were not present at the crime scene.
Types of Cameras and Equipment
Variety of cameras available but quality varies with price.
High-end DSLR cameras can cost around $3,000.
Lesser quality point-and-shoot cameras can be bought for a couple of hundred dollars.
DSLR cameras are vital for taking comparative quality photographs, which allow for resizing of the images to a 1:1 scale.
Comparisons are essential for evidence such as shoe and tire impressions, and fingerprints.
Key Camera Settings
Understanding the three main settings in photography:
Aperture: Size of the lens opening that controls light intake; affects exposure and depth of field.
Larger apertures (smaller f-stop numbers) allow more light, while smaller apertures do the opposite.
Shutter Speed: Speed at which the camera's shutter opens and closes; affects motion blur.
Higher shutter speeds capture fast-moving objects with less light; slower speeds need tripods to avoid blur.
ISO: Measures the camera's sensitivity to light, higher ISO settings are used for low-light conditions but increase graininess.
Effective Photographing Techniques
Importance of taking clear and accurate photographs:
Overall photos, mid-range photos, and close-ups must be sufficiently taken to provide context and detail of evidence.
Use of context in photographs enables juries to understand the scene accurately.
Avoid missing crucial individual photographs that may be important for the case.
Available Light and Ambient Light Photography
Use available light photography to show the scene as it was during the incident, particularly in nighttime situations.
Captures the conditions for witness accounts.
Ambient light photography uses the camera settings to enhance visibility in dark areas, allowing photographs to appear bright even in low-light conditions.
Time-consuming but essential for capturing evidence in dark environments.
Specialized Photography Techniques
Use of infrared (IR) photography:
Captures details that are not visible to the naked eye, such as blood stains on dark fabrics or gunshot residue (GSR).
Requires either an IR camera or a filter on a regular camera; long exposures are often necessary.
Forensic quality photographs with special techniques like oblique lighting are necessary for detailed evidence such as shoe or tire impressions.
Types of Photographs Taken at a Crime Scene
Overall Photographs: Provide context of the entire scene.
Mid-range Photographs: Focus on evidence but still include context (landmarks).
Close-up Photographs: Capture specific details of evidence (e.g., serial numbers on objects).
Conclusion
Correct photographic techniques are crucial for properly documenting crime scenes and gathering quality evidence for investigations and trials.
Emphasis on training individuals adequately in photography techniques to ensure clarity and detail in evidence documentation.