The term 'camera diaphragm' can be broken down into four crossword solutions: IRIS (4 letters), HICS (4 letters), SPLEEN (6 letters), and RIB (3 letters). An IRIS is the adjustable opening in a camera lens that controls the amount of light entering the camera. HICS stands for High-Isochromatic Sensitivity, which is a measure of how sensitive a film is to different colors of light. The SPLEEN is an organ located in the abdomen that helps filter blood and store red blood cells. Finally, a RIB is one of the curved bones that make up the RIB cage. All of these components are important for controlling the amount of light that enters a camera and creating a clear image.