UV photography techniques for ID inspection

Photographing ID cards under UV illumination for documentation or comparison requires a different setup than standard photography. Here is what works and what the common mistakes are.

The basic challenge

UV-reactive features emit visible light when illuminated by UV. A standard camera captures this emitted light, but also captures any visible light reflected from the card surface and the UV light source itself. The result is often an overexposed image where UV features are washed out by reflected light from the UV lamp.

Light source selection

A 365nm UV LED flashlight with no visible light output is the best source for UV photography. The 395nm lights emit visible violet light that appears in photos as a bright purple overlay, masking UV-reactive features. Pure 365nm output keeps the scene dark except for fluorescent features, making them photograph clearly.

Camera settings

Shoot in a dark room with the only light source being the UV flashlight. Use manual exposure mode. Start with ISO 800, aperture around f/4, and a shutter speed of 1/30 second. Adjust ISO and shutter speed based on the brightness of the features you are trying to capture — brighter features need faster shutter or lower ISO to avoid overexposure. Autofocus in darkness is unreliable; switch to manual focus and pre-focus on the card face at the shooting distance before turning off other lights.

Phone vs dedicated camera

Modern phone cameras handle UV photography reasonably well in controlled conditions. The camera app's automatic exposure adjustment sometimes overexposes UV features — use manual mode or a camera app that allows exposure lock. A dedicated mirrorless or DSLR camera with manual settings gives more control, but phone cameras are sufficient for documentation purposes.

Take multiple shots at slightly different exposures to ensure at least one captures the UV features at their correct visible intensity.