Good question.
You would adjust your colors with the RGB knobs on your encoder until you find the color you want. Are you talking about getting something even more specific, like a Pantone color? Exact colors depend on your display and capture gear. You might want to color correct in post for that level of control over color specificity.
If you wanted a sequence of colors, you could use any sequencer. The Korg SQ-1 has a 0-1V mode, conveniently. Other CV sequencers might need to be scaled down (either in their software or using an external CV scaler) to get them in LZX range.
Modulating color in a cyclical way can be done with a slow LFO. An envelope would also work for a repeatable color cycle event.
Just patch any of these sources into your encoderās RGB inputs.
yes iām being specific, e.g. r g b values >255 correspond with buchla module for example, so you could get a precise colour. lets not worry about display or capture gear, the results will all be relative and within some kind of general limits; itās the initial signal Iād like to be correct rather than how itās output or seen, weird as that sounds!
i can do this from a computer or media player, playing a digital clip of color frame/s made in photoshop, but iād like to do it with raw voltage.
if we think of an octave in music as one visible spectrum of colour cycle, each note will have itās own color (i think?). i.e two similar ābluesā will be closely in tune sonically somewhere across octaves. obviously, results depend on things like colorspace environment, but letās not get into that.
lets assume 90 hz is RGB 81,0,120 violet, how can we dial this into expedition or lzx?
or how can we take 90 Hz from audio oscillator and visualize that (without envelope followers).
I hope Iām making sense!? thanks in advance
You are making perfect sense. You want to represent a specific pitch with a specific color. The problem is that light and sound operate in different frequency spectraāand control voltage is in an entirely different range. So an audible oscillation does not produce a color. You would have to associate it with one arbitrarily, and since there is no scientific association between color and pitch, you can make it up!
The easiest way I can think to do this is by multing the control voltage going to your oscillator and sending it to your video encoder at the same time. Keep in mind that sources scaled using the volt/octave standard will only be able to offer LZX compatible voltages at their lowest ranges. For voltages over 1V, I recommend using a module that can scale down to what the encoder wants.
Another thing to remember, is that the RGB inputs on a video encoder control the brightness of each color channel. Patching in a single voltage controls the brightness of all three colors at once, producing a grayscale (0V is black and 1V is white). So you technically need three different control voltage sources to mix RGB colors. A polyphonic voltage source making three note chords would be the easiest to associate with specific colors.
The easiest way is to plug the oscillator into your encoder. You will see the oscillatorās waveform represented by a scrolling pattern of horizontal lines.