Reflected UV Photography
Definition
Imaging where UV light illuminates the scene and the reflected UV is captured. Reveals body fluids, certain fibres, and altered ink without the false-fluorescence problem.
- Illumination
- UV light source directed at the scene
- Captured
- The reflected UV component
- Reveals
- Body fluids, certain fibres, altered ink
- Advantage
- Avoids the false-fluorescence problem of UV fluorescence photography
Common questions
How is reflected UV photography different from UV fluorescence photography?+
Fluorescence photography captures visible light re-emitted by a material after UV excitation, which can produce misleading results when unrelated materials fluoresce similarly, whereas reflected UV photography captures UV light itself bouncing off the surface, giving a more direct and less confusable contrast for certain trace evidence.
What equipment does reflected UV photography require that standard photography does not?+
It needs a UV-transmitting lens or filter, since ordinary camera lenses and glass filters block most UV wavelengths, along with a sensor that has UV sensitivity, so many forensic units use modified cameras or quartz optics specifically for this technique.
Related terms
- Alternate Light Source (ALS)
- A device emitting light at selected wavelengths (typically 415 to 535 nm) used to detect biological fluids that fluoresce or absorb light...
- IR Reflectance Photography
- Imaging where IR light penetrates the surface and is reflected from layers beneath. Reads ink overwrites and obscured tattoos.
- Macro Reproduction Ratio
- The ratio of subject size on the sensor to actual size. 1:1 is life-size; 2:1 is twice life-size. Forensic macros are 1:1...
- UV Fluorescence Photography
- Imaging where UV light excites a substance into emitting visible light, which is then captured with a visible-pass filter. The standard technique...