Six variable vectors exist for the Mega1 secondary, these are selected using the R, G, B, Y, C and M keys. By default they correspond to Red, Green, Blue, Yellow, Cyan and Magenta.
The hue, saturation and luminance within the selected vector can be adjusted using the three controls on the upper left hand side of the control panel. The vector position can be rotated through 360 degrees using the top control on the right of the control panel. The vector width can be altered using the second control on the right of the control panel.The three knobs on the left hand side of the panel are the Hue, Sat and Lum output controls (and their resets). Using these controls it is possible to alter the appearance of a colour depending on which of the Channel Selection buttons is illuminated. For example, if the R (Red) channel is selected, it is possible to alter, say, the saturation of red in order to match two scenes together.
But exactly what is Red? Imagine a set of colour bars on a vectorscope. The red bar is a single point on the scope screen because all the colour red is exactly the same red - it is, after all, a test signal! In the real world of colour grading however, there millions of reds or greens or blues etc.
When you select a channel in Mega1, the system defaults to a wedge of
60 degrees width, centred on red that does not quite reach the centre
of the vectorscope. For most situations this will be quite OK. You will
be able to change all the reds in the picture. Sometimes, though, you
need to be a bit more specific about what you want to change. Mega1 has
the ability to refine the vector width, position and the lower limit of
saturation for what is seen as Red By using the Hue Input Selector
controls on the Mega panel you can alter the position and width of the
wedge.
Although we have been talking about the Red channel of Mega1, it is
possible to alter the position of the red wedge to point at any colour
that you want. Similarly it is possible to alter the width of the wedge
so that, at its thinnest setting there are only a very precise set of
hues in the wedge, up to having every possible hue.
By default, the lower saturation isolation is set to be just away from the centre of our imaginary vectorscope. This is so that black and white are not affected by the output controls. It is possible, however, to alter the lower level of saturation isolation using the controls on the Mega 1 panel in the Platinum display. Clicking on any one of these bars will bring all six controls up on the Blue Display on the transport control panel. Turning a control anticlockwise will decrease the lower limit of saturation isolation - less and less saturated colours will be affected by the output controls, and turning a control clockwise will do the opposite - only more and more saturated colours will be affected.
When you want to alter the position, width and sat isolation, it is sometimes useful to turn the Luminance control up. Now the colours that are being affected will be highlighted, making it easier to see what is and is not being affected.
So, a single channel of Mega1 can be used to change a very small and exact range of colours right up to doing the same thing as master hue, saturation and luminance - and there are six of them!