FLD is a filter for matching daylight film to fluorescent lighting (FL for Florescent Lighting, D for Daylight). On a film camera, you'd use it to correct for the different tone of light and give your shots a more natural looking colour.
Product:
37mm Thread FLD Filter Lens (Purple FL-D Filter Lens / Fluorescent Lighting Daylight Filter Lens)
Link to learn more:
http://dckina.com/index.php?main_page=product_info&cPath=74_86&products_id=2093
SKU: DCK005433
