Filming and television often need an extensive light source which causes deterioration by infra-red radiation in objects of organic materials such as ivory, textiles, parchment, paper, leather and wood. Eleven infra-red absorption filters were tested for elimination of harmful rays from spot lights. The best heat protection was achievedwith a KG1 glass filter (Jenaer Glaswerk Schott u. Gen., Mayence). The Coolight filter (OHARA. Tokyo) was also recommended. Be sides the use of filters to help prevent deterioration other suggestions are to maintain a minimum distance between the spurce of light and the object, to film only in very large and preferably air conditioned rooms, and to reduce as much as possible intensity and time of illumination. Tables give the characteristics of filters tested, the spectral energy transmission of the filters, and the heating effect on the experimental picture at 4000, 8000 and 12000 lux.