Forensic Photography

The systematic use of photography to accurately document people, places, objects, and evidence for investigative and legal purposes.

To create an accurate, comprehensive, and reproducible visual record of the scene and relevant evidence.

Overall, midrange, and close-up views.

An image documenting the general scene layout and relationships among major locations and objects.

An image showing evidence in relation to nearby landmarks or other significant scene features.

An image documenting the detailed appearance of a particular item, mark, or area of interest.

The unscaled image records the unobstructed evidence, while the scaled image provides a measurement reference.

A calibrated reference placed near evidence to indicate dimensions in an image.

To reduce perspective-related measurement errors.

To provide perpendicular measurement references useful for documenting dimensions and orientation.

A change in apparent shape or relative dimensions caused by the camera's position and viewing angle.

To minimize perspective distortion and improve the accuracy of its recorded proportions.

The adjustable opening in a lens that controls the amount of light entering the camera.

The ratio of lens focal length to the effective aperture diameter.

The aperture becomes smaller, assuming the same lens focal length.

The range of distances within a photograph that appears acceptably sharp.

It generally increases depth of field, all else being equal.

The length of time the camera's shutter allows light to reach the image sensor.

Loss of image sharpness caused by movement of the camera or subject during exposure.

It stabilizes the camera, improving consistency and reducing motion blur during longer exposures.

A camera sensitivity or exposure-index setting that influences image brightness and noise characteristics.

Unwanted variation in pixel values that can reduce image clarity, especially under challenging exposure conditions.

The amount of light recorded by the camera sensor during image capture.

The relationship among aperture, shutter speed, and ISO settings in controlling photographic exposure and appearance.

A camera or processing adjustment intended to render colors appropriately under different lighting conditions.

It may produce misleading color representation of stains, materials, or other evidence.

To provide a documented reference for evaluating color reproduction under the capture conditions.

A format that preserves minimally processed sensor data, allowing controlled image processing while retaining substantial capture information.

They can preserve original capture information and support documented, reproducible image adjustments.

A commonly used lossy image-compression process that reduces file size by discarding some image information.

Repeated lossy compression may introduce artifacts and degrade fine detail.

Information associated with an image file, such as camera settings, timestamps, device information, or processing details.

Exchangeable Image File Format.

No. Device clocks and metadata can be incorrect or altered, so timing may require corroboration.

A calculated digital value used to help verify whether file contents have changed.

That the compared files have identical contents under the specified hashing method, assuming the process is reliable.

The documented application of processing techniques to improve visibility or interpretability without misrepresenting the underlying evidence.

To permit evaluation, reproducibility, and disclosure of any processing that may affect interpretation.

A controlled illumination source using selected wavelengths to help visualize particular materials or features.

Imaging light emitted by a material after excitation by illumination at another wavelength.

To block selected excitation wavelengths while transmitting desired emitted light to the camera.

Illumination directed at a shallow angle across a surface to emphasize texture, relief, or impressions.

It can produce shadows that reveal surface features and depth variations.

The extraction of measurements or three-dimensional information from photographs using geometric relationships and appropriate calibration.

A wide-field image assembled or captured to show an extended view of a scene.

Stitching and projection may distort geometry, and fine details may not be recorded adequately.

To document spatial relationships, movement paths, and general scene conditions in a continuous visual record.

To retain the source recording for authenticity assessment, comparison, and review of any edited presentations.

Perspective distortion may compromise accurate comparison and measurement.

The preserved original image and documentation of the enhancement method, purpose, and relevant limitations.