Olympus Fd-1 Macro Flash Diff The FD-1 efficiently diffuses the light from the camera's built-in flash for even lighting during macro photography, perfect for capturing moving subjects up close and for shooting underwater macro. Improved light distribution darkens the background to make subjects stand out. The FD-1 features a light intensity adjustment lever that allows users to select either high or low output (a 1.4 step increment) to accommodate a variety of subjects. Illumination distance: 2 to 30 cm. The FD-1 may also be used underwater.