The BBC65 is a new version of the former BBC No. 59 test chart. It was developed to fulfill the need for a simplified studio test chart giving only the necessary information for routine day-to-day camera line-up in the shortest possible time.
In designing the chart, the selected line-up level have been confined to the important central area where it is necessary to obtain optimum balance. The test chart use the same baseboard construction as the BBC64 Color Camera Gray Scale Chart and features a central “Super Black“ for the adjustment of flare correctors. The sensitivity of flare correction adjustment is increased by a background brightness which is twice that of test chart BBC64.
The central strip of black flick is included to display a sample of the shading effects near black level due to flare and other causes. This facility enables the optimum setting of black level balance to be achieved when matching cameras which may differ in these parameters.
The large area of neutral gray will clearly display any “white” shading errors that may be present.
The BBC Test Chart 65 is seen as complementary to the full-range gray scale test chart BBC64 which must be used when it is required to examine the complete signal excursion from black level to peak white.
Background reflectance: 34% “White”: 60%
Dark gray: 7% Black: 1.5 %
Super Black; over 100: 1 relative to white level
Test chart components mounted on 22mm block-board with raised mounting all round to prevent damage to edges. A plastic cover sheet provides additional protection (similar to BBC64).
A BBC65 is placed on a lighting stand in the center of the scene and the camera exposures adjusted so that the white 60% step in the center and the large black level reference conform to the normal waveform monitor limits. Color balance controls are then adjusted for optimum color balance on all cameras. The BBC65 is designed to be used in conjunction with the test chart BBC61A Flesh Tone Reference when very close color matching is required.
