Hoya 77mm R72 Infrared Filter
This filter is used for photography with infrared films. Infrared film is also sensitive to ultraviolet rays and the shorter wavelengths of the visible spectrum so it is necessary to filter out all but the infrared rays. Hoya makes two types of infrared filters: R72 passes only infrared rays above 720nm; RM90 passes only that above 900nm.
- Hoya 77mm R72 Infrared Filter
- Limited Warranty