Since humans cannot see ultraviolet light, we use UV imaging to see how UV light is reflected from the feathers of waterfowl.  The specimens are illuminated with a UV lamp and are imaged with a digital camera equiped with lens filters that block all visible light.  The camera converts the UV light it recieves into visible light to produce a monochromatic image.  The feathers that reflect UV light show up as white areas in the UV image.  All UV absorbing areas appear dark in the UV image.