While we’re still working with black and white levels, we can introduce TriCaster’s Vectorscope, and perform an initial test of the camera’s color balance.
A vectorscope (Figure 297) can be likened to the familiar ‘color wheel’ (Figure 298) which sweeps radially through the colors of the spectrum – yellow, red, magenta, and so-on, around the arc of a circle. Colors are more progressively intense (saturated) towards the outside of the circle, while color saturation is zero at its center.
As it happens, from the vectorscope point of view, neither black nor white properly have any color saturation. Thus with the lens cap on (or with a white card filling the viewfinder), the vectorscope should show only a small fuzzy trace at its center. If the fuzzy dot is off-center horizontally or vertically, this would indicate that the camera is incorrectly calibrated, actually tinting gray areas.
When the trace is off center, the direction and distance of the offset tells us what sort of tint (and how much) is represented by the deviation. You may be able to use the color controls at your camera to correct for this offset, or you can use the U Offset and V Offset controls in TriCaster’s Proc Amp to do so (as always, source controls are best). Adjustments to U Offset move the trace left or right, while V Offset changes adjust its vertical position.
Let’s move on to a slightly more rigorous testing.
For more information please download the entire document at new.tk/rt-m