Abstract: A novel spotlight where the position of image formation does not change even when the zoom adjustment is made after focus adjustment, so that focus adjustment and zoom adjustment can be facilitated. When a drive shaft (10) is rotated by operating a zoom adjustment handle (5), a lens (4a) moves forward and backward according to an unequal pitch (P1) of a first screw section (15), and a lens (4b) moves forward and backward according to an equal pitch (P2) of a second screw section (16), so that the distances between the lenses (4a–4c) are changed and zoom adjustment is made. Focusing adjusted by a focus adjustment mechanism (b) does not change even when the distances between the lenses are changed. Therefore, focus adjustment and zoom adjustment can be made extremely simply, and the spotlight can be used particularly useful in performance space such as TV studios and theater stages.

Abstract: A dimming-control lighting apparatus for an incandescent electric lamp with less accompanying color temperature change, using a dimming power source installed in TV studios or theater stages, is disclosed. The voltage of the first filament whose rated voltage is lower than the maximum output voltage of a dimming power source rapidly rises to the sawtooth voltage of the dimming power source, and after the first filament reaches a constant color temperature, the output of the second filament having the same rated voltage as the maximum output voltage of the dimming power source is delayed to thereby light the second filament.

Abstract: A lighting device includes a reflector that has forward and rearward segments separated by a clearance for cooling, a gobo holder into which gobos of differing sizes can be inserted and held in position, and a lens holder which can be moved forwardly and rearwardly in the lighting device by rotation of a gear which is attached to the lens holder and engages a rack in a slide guide in the lighting device, the gear being moved by a knob located outside the lighting device and which is rotatable with the gear and movable along the lighting device.

Abstract: A dimmer for an incandescent lamp, wherein a phase angle controlling dimmer for performing one time ignition operation every one period of a power supply waveform is used, the ignition angle is varied continuously to perform an optical adjustment operation, each of the electrical powers of positive half cycle and negative half cycle is supplied to individual filaments of a bulb so as to enable an optical adjustment of less variation in color temperature to be attained.