Dynamic Range
Definition
The ratio in exposure stops between the brightest recordable highlight and the darkest shadow detail above the noise floor; typically 12-14 stops in modern full-frame cameras.
- Unit
- Exposure stops
- Typical full-frame range
- 12 to 14 stops
- Lower bound
- Sensor noise floor
- Upper bound
- Sensor clipping/saturation point
Common questions
Why does dynamic range matter in forensic photography?+
A scene with deep shadow and a bright flash-lit foreground, common at night crime scenes, can exceed sensor dynamic range, causing shadow detail to be lost to noise or highlight detail to clip to pure white. Bracketed exposures or RAW capture preserve the wider range for later processing.
Does a higher ISO increase dynamic range?+
No. Raising ISO amplifies the signal after capture and generally reduces usable dynamic range because it also amplifies noise in the shadows. Dynamic range is best preserved at the base ISO of the sensor.
Related terms
- ABFO No. 2 Scale
- The right-angle L-shaped reference scale with circular targets used in bite mark photography. Its design enables post-capture correction of lens distortion and...
- CCD (Charge-Coupled Device)
- A sensor architecture that transfers accumulated pixel charge across the array to a single output amplifier, producing uniform noise characteristics suitable for...
- CMOS (Complementary Metal-Oxide Semiconductor)
- A sensor architecture with per-pixel amplifiers, enabling fast readout and low power consumption; BSI-CMOS variants now dominate professional forensic cameras.
- Depth of Field (DoF)
- The zone of acceptably sharp focus around the focused plane; controlled by aperture, focal length, and subject distance. Critical for close-up evidence...
- Diffraction Limit
- The aperture threshold below which wave diffraction at the aperture edges degrades resolution more than the narrower aperture improves depth of field....
- F-Stop
- The ratio of focal length to aperture diameter, expressed as f/number. Lower numbers mean wider aperture, more light, and shallower depth of...
- Focus Stacking
- A computational technique combining multiple images focused at sequential depths into a single all-in-focus image; used for three-dimensional evidence with relief exceeding...
- ISO
- A standardised sensitivity rating for digital sensors; higher ISO values amplify the output and allow lower-light capture but introduce random noise that...
- Oblique Lighting
- A lighting geometry with the source at 5-30 degrees to the evidence surface, casting long shadows that reveal surface relief. Standard for...
- Ring Flash
- A circular flash tube mounted around the lens that illuminates from all azimuths simultaneously, producing uniform shadowless illumination used for bite-mark and...
- White Balance
- A camera setting that corrects for the colour temperature of the ambient illuminant, ensuring neutral colours render as neutral. Manual white balance...