IR Reflectance Photography
Definition
Imaging where IR light penetrates the surface and is reflected from layers beneath. Reads ink overwrites and obscured tattoos.
- Mechanism
- IR light penetrates surface, reflects from layers beneath
- Reveals
- Ink overwrites, obscured or covered tattoos
- Contrast source
- Differential IR reflectance between materials
- Setting
- Crime-scene and document photography
Common questions
How does IR reflectance differ from IR transmission photography?+
Reflectance photography captures IR light bounced back after penetrating a surface layer, useful when the material beneath is opaque to visible light but still on the same side as the camera, whereas transmission photography passes IR through the whole document from behind.
Why does this technique work on covered tattoos but not all skin markings?+
Different inks and pigments absorb or reflect infrared to different degrees depending on their chemical composition, so a covering layer that appears opaque in visible light can still let IR pass through or reflect differentially if the underlying pigment has a distinct IR signature; some pigments show no such contrast.
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