Fundamentals of Forensic Photography

Practical Techniques for Evidence Documentation on Location and in the Laboratory

Keith Mancini, John Sidoriak

• Publisher: Routledge
• Year: 2017
• ISBN:
  9781317435389
• Edition: 1
• Topic: Art
• Subtopic: Photography

In Fundamentals of Forensic Photography, Keith Mancini and John Sidoriak offer practical techniques for common situations encountered in forensic documentation. Topics include equipment selection, lighting techniques, crime scene and evidence documentation, macro and micro photography as well as aerial, high speed and computational photography. Techniques for photographic documentation in both the laboratory and the field are discussed.

Chapter 1 Equipment and Technology

Cameras

Undoubtedly the most important piece of equipment for forensic photography is a camera. Evidence documentation is essential and the camera is the forensic photographer’s primary tool to preserve a moment in time. As time keeps moving, evidence will as well. The camera stops time and captures evidence in its existing location for analysis.

The camera is essentially a light tight box that contains a sensor, which records light and converts it into electronic signals, and supports a lens that focuses light upon the sensor. The camera will also have a mechanism to control the amount of light striking the sensor, usually a shutter and aperture. All cameras share this same basic design; however, the variety of features beyond this basic design can be overwhelming when deciding upon a camera. Choosing the right camera for you will depend upon its intended use as well as your budget. Recent advances in digital imaging technology have considerably blurred the lines between what is a professional camera and what is a consumer camera, so when deciding what is the right camera for your task it is more important to consider individual features and what your needs are. Nevertheless, there are some general categories of cameras that should be discussed. Generally speaking the following types of cameras go from more advanced to least. However, there will always be exceptions to that rule; for instance, a high-end point-and-shoot camera may outperform a low-end DSLR and this can only be determined by comparing their features. The camera has evolved and the future of camera technology is unknown. Despite the advances cameras have experienced, we still come back to the ultimate goal of a camera, and that is to take a picture and record data and evidence. There are some general categories of cameras that will be covered in this chapter. However, they can only be determined by comparing their features and if possible testing camera systems in a controlled environment.

Components of Cameras

Cameras from the professional level to the everyday smartphone will contain the same parts and mechanical devices. Every part and mechanical device will produce the same effect for the same reasons. The overall idea is to record light during a set time period. The camera housing, or black box, eliminates extraneous light sources from activating the sensor. The light entering the camera housing must be mechanically controlled to create a proper image. A shutter is used to control the light entering the camera at the location of the lens. The lens focuses the light entering through the shutter onto the sensor. The sensor is located at a specific distance from the lens and permits proper focusing of the image.

DSLR Cameras

Short for digital single-lens reflex, these are probably the most common cameras used by forensic photographers. The DSLR is the most versatile camera system available by way of having a multitude of settings, options, lenses, and accessories. DSLR cameras have a mirror that directs light from the lens into the viewfinder allowing the photographer to see what will be recorded once the photograph is taken. The ability to see in the viewfinder what will be the captured images permits the photographer to compose the image and focus on specific information, which is a must for forensic evidence gathering. Once the shutter button is pressed, the mirror moves out of the way allowing the light to expose the sensor.

DSLR cameras accept interchangeable lenses allowing the photographer to select the best lens for the task at hand. Interchangeable lenses also allow the photographer greater control over composition, color, clarity, focus, speed, and depth of field. Environment, location, and the subject will influence the photographer’s lens selection. Each photographer may have a “go to” lens that they would use as their primary lens. Additional lenses will aid in expanding the photographer’s and camera’s capabilities. Each camera manufacturer uses its own mounting system for lenses, called a lens mount, and not all systems are compatible. Therefore it is important to have the correct lenses for your DSLR camera. One way to accomplish this is by purchasing lenses such as Canon, Nikon, Sony, or Leica, made by the same company as your camera; however, there are several lens manufacturers that make lenses in a variety of mounts. An expanded description of lenses will be given later in this chapter.

DSLR camera digital sensors come in a variety of sizes, but tend to be larger than those of cameras in other categories, with the exception of medium- and large-format cameras; however, these tend to be very expensive and are not common to forensic work. The full-frame sensor is currently the largest available sensor for DSLR cameras. It is called “full frame” because of its evolution from 35mm film cameras with it replicating the view within the viewfinder that many trained film photographers are accustomed to seeing. Traditional film photographers are not accustomed to the LCD display on the back of the camera. The full-frame sensor also replicates the field of view many tradit...

Table of contents

• Cover
• Title
• Copyright
• Contents
• About the Contributors
• Acknowledgments
• Introduction
• 1 Equipment and Technology
• 2 Basic Photography Principles
• 3 Digital Photography
• 4 Light and Lighting
• 5 Crime Scene Documentation
• 6 Evidence Documentation
• 7 Aerial Photography
• 8 Close-Up and Macro Photography
• 9 Photomicrography
• 10 High Speed and Time-Lapse
• 11 Computational Photography
• 12 Digital Image Processing
• Index