Black-eyed susan visible and UV light IRUV-216
Two exposures. Nikon D2H with EL-Nikkor 135mm enlarger lens mounted on a Nikon PB-4 Bellows, on a tripod. One exposure was captured with no filter and with visible light. A second exposure was captured with "Venus" filter attached to record UV (ultraviolet) light. The two images were blended in Photoshop.
The petals absorb and reflect UV light in a different pattern than visible light. Some insects can see UV light and it is thought these patterns may help guide them to the nectar.