Overcoming the Hum Bar and Strobing Problem in Metal-Halide Lighting at the Power-Supply Generator
The subjects of hum bars and glitches on television and strobing on motion-picture film are discussed. When using metal-halide lighting, these defects are caused by differences between the power-supply frequency and the frame-sampling rates of television and film systems. A method of overcoming these problems is suggested, with special reference to mobile generator sets. Most investigators have approached these problems by adding correcting devices to the light source. The author has gone a stage farther back, correcting the problem at the power source. Control of the power-generator frequency and phase is linked to the television sync pulse. A sync-pulse delay is used to correct glitches. Adjustable crystal control is employed for motion-picture use.
- Print ISSN
- 0036-1682
- Published
- 1979-04
- Content type
- Original Research
- DOI
- 10.5594/J10413