Width x Length
It is difficult to add colour to light, because light is usually associated with heat. Not every plastic film can withstand the temperatures that occur on a lamp. Rosco E-Colour colour filter films are designed for use in theatres and films and are therefore suitable for colouring the light beam of a powerful spotlight. Long-term irradiation of E-Colour colour films with a UV-containing light source can lead to slight fading of the film.
In order to get an impression of the light colour generated by a colour filter film, the light is shone onto a surface by the corresponding colour pattern. Simply holding the light in front of the eye usually creates a false impression.
A few points need to be borne in mind when constructing luminaires: the distance from the incandescent or halogen lamp is not the only important factor in determining the temperature of a colour filter film. Rather, the ventilation of the luminaire plays a very important role. Just as the reflector on the top of a classic desk luminaire usually has a few holes, the self-constructed luminaire should also be designed in such a way that the hot air rising from the light source can flow upwards. In this way, a cooling air flow is created in the luminaire as if by itself. A further heat aspect: the heat radiation in the light beam of a spotlight with reflector is usually much stronger than in a spotlight with lens system, as the reflector, unlike the lens, also concentrates the heat radiation.
A simple coloured luminaire is created when you cover a fluorescent tube with coloured filter foil. The temperature of a fluorescent tube is far below that of other light sources, so that the colour filter foil can be applied directly without any problems. Here, as well as in the construction of luminaires with incandescent or halogen lamps, invisible Scotch Magic Tape is ideally suited for gluing the film, as it is heat-resistant up to 150 °C. The film can be applied directly to the luminaire without any problems.
Colour filter foils are very thin, so they can be easily cut with a cutter or scissors. Their low thickness is a disadvantage if the construction requires a certain inherent stability. Perforated sheets, wire mesh or expanded metal with the largest possible open area (ao) can then be used as carrier material. Polycarbonate or polypropylene panels are also well suited due to their higher heat resistance if sufficient ventilation is provided for the luminaire. The colour filter films can be joined to each other and to other materials with heat-resistant adhesive tapes, rivets or clips. For constructions exposed to high temperature differences, note the different degrees of expansion of materials. Avoid, for example, large-area bonding of metal to filter foil, as the stresses that occur quickly fatigue the connection.