The Effect of Automatic Black Level Control on the Quality of Television Film Images
Observers judged the quality of the display of 63 different color film commercials as a function of the black-level control used. For two commonly used telecine cameras, use of the standard automatic black-level (ABL) mode resulted in a significant reduction in picture quality, compared with use of the manual mode, unattended (UMB). Excessive picture contrast and loss of shadow detail, as well as occasional darkening of middle tones, were observed. A change in ABL circuitry in one camera resulted in some improvement. A test of a newer camera showed that the ABL circuitry in that camera did not degrade picture quality. As a result of this test it is suggested that, if the telecine camera is properly set up, use of the unattended manual black mode should be considered in preference to use of ABL control.
- Print ISSN
- 0361-4573
- Published
- 1973-10
- Content type
- Original Research
- DOI
- 10.5594/J08141