Posts Tagged ‘tune’
Just as along with studio flash, incandescent lighting can be modified with some other attachments, although these must always be heat-proof and adequately ventilated. 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.
Many housings allow some switch to the beam pattern by moving the lamp in and out of the reflector, or by moving reflector doors. Barn doors designed for some housings have a slightly different effect: they cut the sides on the beam instead of concentrate it. The beam patterns from most housings show a fall-off from the center outwards; despite having a well-designed reflector, there exists still a powerful strength of light in the lamp’s filament. One way of reducing this fall-off within the design of the housing is to cover the lamp from direct view with a bar or a spiller cap. In the event the reflector dish is large as well, the result is a degree of diffusion. Even softer, but less intense light may be possible if the inside of the dish is finished in white instead of bright metal.
Used alone inside the studio, tungsten lamps simply need 3200K incandescent white balance. However, tungsten lights are used often on location, in interiors, and that is often in combination with existing lighting like daylight and fluorescent light. For that reason, lighting filters are usually employed for converting the colour 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 most typical filters are blue, to complement daylight. Full blue is -131 mireds; half-blue is -68 mireds; and quarter-blue is -49 mireds. These filters are available as heat-resistant gels, glass and dichroic. Dichroic filters are partial mirrors, reflecting red back in the lamp and passing blue; they are not always consistent, and ideally needs to be checked before use with a color-temperature meter.
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.