On 08/07/2013 11:23 AM, Robert Crow wrote:
Rips like Mirage and Overdrive use the same route - but with a far better front end and I've been told, off list, that some other RIPs using RGB drivers use the printer manufacturer's more adjustable SDK version of the driver rather than the OS - I need to test those becuase in the past I found some which claimed RGB drivers still gave less pleasing results to the OS driver
The issues I've had with some rips was not the colour per-se, but the screening and break up in the gradients. It is an issue driven partly by colour though in my opinion...
...for example, if you print a pure blue gradient via the Epson canned profile for their Premium Semigloss paper, it is evident (to me at least) that some 'purity' of colour has been sacrificed in order to achieve a smoother gradient (versus my custom 'colour accurate' profile). Perhaps this is where photographers are at odds with the graphics world? i.e smooth transitions of colour and tone vs absolute colour accuracy? After all, a toned (or duotone) image is often favoured over a purely neutral one in for this reason.
RIP manufacturers naturally concentrate on colour (often in blocks) hitting precise Lab values whereas the inkjet manufacturers know that photographers are interested in balancing colour against a more subjectively pleasing smoothness.
Rob
Qimage Ultimate too on Windows. Duotones can be kept neutral too in conventional printing, no need to add a color tone. Laying down two halftones with or without a partioning on the tone range already improves the gradients. If no moiré is introduced by that complexity. The color toning is a choice. In inkjet printing similar duotone effects can be achieved in quad inksets with enough overlap on the monochrome inks or more radical on desktop models loading all the channels of a 1.5 picoliter head with the same black. By the last method also forcing them to the minimum droplet size at more printer resolution settings than the highest mode. Differences per channel or nozzle on cheap desktop printers are equalised that way. A high number of nozzles per channel helps too of course, thermal heads have an advantage there. The compromise between speed and image quality remains, more weaving done takes time. Whether more pleasing image quality at dithering/weaving level should affect color description is not clear to me. The color description is in the printer profile and that sets the gamut limits too. With the right input file description the chosen rendering should deliver the goods within that printer gamut or clip on the gamut boundary. I think the main issues happen in the color model translations, Spotcolor/CMYK descriptions through an RGB-device printer profile to a CMYK/N-color printer. But the HP Z3200-PS model does that task quite good through its OEM Printer Utility path or PS3 driver and still offers a simple RGB-device path with the PCL3 path. Pantone descriptions tweaked by HP engineers to printers that can be easily calibrated by the user later on. -- Met vriendelijke groet, Ernst Dinkla http://www.pigment-print.com/spectralplots/spectrumviz_1.htm December 2012: 500+ inkjet media paper white spectral plots.