Converting to 8-bit does seem undesirable but it's not nearly as bad as it might seem.
16-bit is very necessary during all the editing phases but at print time it's not critical.
In Photoshop (Use Dither should be on in Color Settings) and in Print-Tool the conversion
of 16 to 8 bits uses dithering based on the bottom 8 bits. So for instance a K=50 in 16-bit
is halfway between 127 and 128 in 8-bit. The 16-to-8 conversion doesn't pick 127 or 128,
instead it will have half 127 and half 128 using a dither pattern. A gray patch will be
indistinguishable. Another way to look at it is the driver will be converting everything to
just 1-bit -- i.e. a drop of ink or not -- so this is just an intermediate step 16->8->1 vs 16->1.
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Try it out.
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I'm guessing you realize that in PS printing you will get CM conversions -- not just time usage
but tonal changes. Actually I think if you Assign Profile sRGB before printing you may avoid
the tonal change in PS -- but you are in RGB then 3 channels instead of 1.
Roy
On Fri, Feb 12, 2016 at 6:06 AM, richard@... [QuadtoneRIP] <QuadtoneRIP@yahoogroups.com> wrote:
These were 16-bit flattened grayscale, but I will rotate in photoshop before printing. Thanks for that suggestion. On the 44x108 I had it printing bi-directional, but i will see what the difference in time is when printing 16 bit compared to 8 bit. On a philosophical level I just hate the idea of throwing away bits...I usually don't print with ICC profiles and print with no color management from PrintTool, and when I am printing from Photoshop I will just leave it as "printer handles color". Next time I print one of these large ones l will compare the difference between printing through photoshop to see if that internal conversion from graygamma 2.2 to sRGB is causing some of the additional spooling time compared to no color management from PrintTool. This is stuff to keep me occupied when these things take so long, but otherwise I'd never worry about it.Thanks again,Richard Boutwell