The infrared compensation index is a camera adjustment used to correct focus when shooting black-and-white infrared film. Because infrared light focuses at a slightly different point than visible light, this compensation ensures that images remain sharp. Colour infrared (IR) film typically does not require this adjustment.
Understanding and using the infrared compensation index is essential for photographers working with infrared black-and-white film, particularly in landscape or experimental photography. Proper compensation allows precise focus, ensuring crisp details and maximizing the unique visual effects that infrared photography can provide.