... ,830nm,850nm and so on. Used for photography with infrared films.Infrared film is also sensitive to ultraviolet rays and the shorter ... to filter out all but the infrared rays. 2)Size:from 25mm to 86mm,fit most camera lens diameter,or square shape ... can manufacture all kind of optical glass, optical filter, near infrared glass, transmission ultraviolet black glass, neutral grey glass, green glass ...