Fine Tune Incandescent Studio Lamps
Every type of incandescent light housing incorporates some type of reflector behind the lamp. It is partly to make use of each of the light radiated and partly to manage the beam.. The deeper and much more concave the reflector, the more concentrated the beam. As it is more challenging to spread a beam which is already tight if this leaves the housing than it is to focus an extensive beam, most general-purpose housing has reflectors that provide a range which is between about 45 and 90 degrees. Light that provides tighter concentration is intended for more specialized use.
Moving the position of the lamp in its reflector changes the spread of the beam. When it is farthest, the beam is quite narrow while if it is moved forward and the doors are wide, the beam spreads. Lighting filters are usually employed for converting the color temperature or for correcting the color to that of fluorescent lamps. You could use mixed lighting and post-production methods, but it is best to get it right on the shoot.
The reflector angle in certain tungsten lights where the lamp position is fixed allow a lens-precise control over the beam spread with hinged reflector panels. These are the basic configurations, but the hinges can be moved separately. Moreover, it is often convenient to filter each lamp instead of using a lens filter on the camera. Fittings vary, but usually you do not close the lamp to avoid over-heating. A universal fitting is an outrig frame, which attaches in front of the light. It is recommended to use purpose-made non-flammable filter material with any kind of lamps.