Infrared filters, sometimes called IR filters or heat-absorbing filters, are designed to allow IR mid-infrared wavelengths while block visible light. They are often used in devices with bright incandescent light bulbs (such as slide and overhead projectors) to prevent unwanted heating | Digital cameras are usually equipped with IR-blocking filters to prevent unnatural-looking images. IR-transmitting (passing) filters, or removal of factory IR-blocking filters, are commonly used in infrared photography to pass infrared light and block visible and ultraviolet light. Such filters appear black to the eye, but are transparent when viewed with an IR sensitive device | The creative adjustable IR filter is a compact all-in-one variable wavelengths filter that adjusts the amount of wavelengths with just the twist of your wrist. The index marks on the filter let you know exactly the amount of wavelengths at a glance. Giving you clear and precise shots at whichever wavelengths you are using. It offers you the freedom to create different wavelengths freely | You don't have to carry a bunch of filters for shooting. Just one filter, gives you from the range 530nm to 750nm freely