Results
What did unbridled success ever teach us? Try something else. There's always something to learn from failures though. Here are the results and my take on what they mean. The test was performed on Silver Agfa MC paper using a #5 filter, using Epson OEM Dye Ink in my R300. The original RNP Array was printed with a black-chipped yellow cart replacing the black cart to produce a CcMmYY printer. My thinking was that this would eliminate the chances of black ink causing grain at higher densities. This just didn't happen. The driver simultaneously cuts back on the coloured ink as it adds the black ink causing the cancellation of any gains in this area. I might as well have just been shooting water or glop (gloss optimiser) out the black-chipped cart. End of story. Or not.
If there is a little light at the end of the tunnel it might take the form of showing us where the black ink "is not" present in the over-all scheme of things. It's more apparent in the first post where you can actually see the colours printed to the OHP material. In my estimation "real" black ink doesn't get applied until about 65% Brightness (below the equator) and in some cases (pure Yellow) the Epson driver obviously used fake black or rather combined CcMmY black until around the 45%-50% Brightness range. This actually confirms something I suspected a while back while examining the RNP Array when I scanned it as film and "looked" at the actual ink dots. Black is much more easily seen that the combined colour dots and especially when looking at a wedge that is stepped they will suddenly appear on step when they weren't present on the previous step. Plotting where the black ink is potentially important because it shows that the usable range of colours a printer can use for producing density (without invoking black ink) is actually much larger than previously thought (i.e. any system which only represents the colours on the equator read: the earlier RGB-RNP Array or PDN).
I could try yellow chipping the Magentas or the Cyans but I think it's going to produce the same trade off, or just get more strange colour shifts occurring in different areas but with no real benefits or gains as far as density or smoothness go. Next!
~m
Below: Two test prints. The first shot at 15 seconds (too dark) the second I cut the time back a third to half a stop to 12 seconds (better). The top print on both is using CcMmYK and the bottom prints are the CcMmYY.
