Photographic Scales L Shape

Description

Rigid, L-shaped piece of laminated plastic 1 mm thick millimeter markings accurate to 0.1 mm or better overall size is 5 cm x 5 cm

grey areas have a reflectance value of approximately 18% alternating black and white bars (1 cm) to permit measurements from grossly over and underexposed photographs

The incorporation of three circles is useful in helping to compensate for distortion resulting from oblique camera angles.

The graduations are all metric, except for the width of the legs which are 1-inch wide, the 1-cm

division lines are traced and extended across the photographic print to grid an image.

Measurements within the image are then made relative to these inscribed 1-cm grid lines to compensate for any distortion resulting from non-parallelism between the film and the object planes.

Notes:

Photographic scales, labels, and rulers are essential tools used in documenting and analysing crime scenes and forensic evidence in laboratories. These tools play a crucial role in ensuring the accuracy and integrity of photographic evidence, aiding in the investigation and legal proceedings that follow.

Photographic scales, often referred to as measurement scales or reference scales, are regularly used in crime scene photography to provide a standard reference for size and distance measurements within an image. These scales typically consist of a series of black and white or color-coded blocks or markings of known dimensions, which are placed in close proximity to the evidence being photographed. By including the scale in the photographs, forensic investigators and analysts can accurately determine the size and proportions of objects within the images, aiding in the reconstruction and interpretation of the crime scene.

Labels are used to provide essential information about the photographed evidence, such as its location, date and time of collection, case number, and a brief description. Proper labelling is critical for maintaining the chain of custody and ensuring that the evidence can be accurately tracked and associated with the corresponding case file throughout the investigation and legal process.

Rulers, often with both metric and imperial markings, are used to measure the size and dimensions of physical evidence in the crime scene and forensic laboratory. These rulers provide a standardized reference for documenting the length, width, and height of items, as well as the distances between objects within the scene. Additionally, specialized forensic rulers with contrast patterns or colours are used to enhance visibility and accuracy when photographing items with varying surface textures and colours.

In conclusion, photographic scales, labels, and rulers are indispensable tools in the field of forensic science and crime scene investigation. Proper utilization of these tools ensures that photographic evidence is accurately documented, providing crucial information for investigators, analysts, and legal professionals as they work to uncover the truth in criminal cases.