Recently, at least by my glacial standards of time, someone (thanks, Andrew!) suggested to me the idea of making a timelapse recording of my pixel-pushing process. I hadn't done anything like that before, but I did have a fun concept for a blog title along with a matching image, so I decided to give it a go.
The result is obviously plastered all over this blog's header, but here's the video:
The idea was to restrict everything to four CGA colors (the high-intensity "alternate" palette of cyan-red-white) while still working in layered RGB, so I could still have all the amenities at my disposal, unlike the crippled afterthought that is PS's indexed color mode. I also wanted to simulate intermediate levels by using three 50% dither patterns (black/red, red/cyan, cyan/white) just as if they were solid colors.
After a couple of failed experiments, I stumbled across a convoluted little method that somehow seemed to work: do the actual drawing in greyscale, but slap a series of 7 adjustment layers on top of the whole thing. Each is triggered by a certain range of grey levels and displays a corresponding CGA color (or dither pattern).
Here's the actual stack of layers; Color Fills for the 4 solid colors, and Pattern Fills for the dither patterns (from Layer -> New Fill Layer, select solid color or pattern respectively). For each layer, the input range of greys is specified in Layer -> Layer style -> Blending options. For instance, the pattern layer for alternating black/red pixels is set to blend only when the underlying layer's grey level is between 65 and 67:
The rest of the layers are set up similarly (as you can probably tell by their names), covering the entire 0-255 range. I gave the "dither" layers much narrower ranges than those of the solid colors - this is just to have finer control over things, otherwise different color pixels can crop up uninvited with things like smooth-edged brushes. Then I set up a handy "palette" image, so I could quickly color-pick while drawing by holding down Alt and clicking a shade of grey:
So all the actual drawing is done in grey, beneath the fill layers, but as you're drawing, What You See Is What You Get - the state of the art on early '80s IBM PCs and compatibles, 2-bit color pixels in all their glory.
The final drawing...
...actually looks like this "under the hood":
This little trick allowed me to combine several techniques here - pixel-precise mouse work for most of the details and shading, anti-aliased curves for drawing outlines with the Pen tool, importing a scanned pen-on-paper drawing (for the "MPH" part), and using a Wacom pen tablet (for most of the background work). I daresay it turned out nice... perhaps not quite on Asphyx-levels of awesome, but I have no presumptions.
Because of the extremely limited palette, it pays off to treat the colors as nothing more than their brightness levels: the result can often look good even when you switch to an entirely different set of colors, as long as they have a similar relationship in terms of luminosity. Of course, this isn't limited to CGA artwork only - the Amstrad CPC has a very similar 4-color video mode, for instance.
This particular method wouldn't work too well with larger palettes however, since the tower of adjustment layers would quickly grow to unwieldy proportions. A program that's actually tailored for this kind of pixel-pushing, such as Grafx2, would obviously be a much better choice (would be nice to get off my ass one of these days and actually learn how to use it).