David, The Ultratone profiles you have were made before the dot size weighting change. You might want to re-check the partitioning with the full calibration procedure. Carl On Friday, November 14, 2003, at 05:50 PM, David Wroblewski wrote: > Sorry to be taking up so much bandwidth on the group while > converting my 2200 from UltraChomes to UltraTones. I'm almost > there, but I have a question about getting that last few percent > of precision out of my setup before I start seriously burning through > ink and paper. To be clear, this QTR on Linux, with a Epson 2200. > > Background: I've installed the UltraTone carts, cleaned & checked > the nozzles until they are firing perfectly. I have the toner-curve.raw > file with the correct bit order for Linux. I've installed Carl's 2200 > UT curves, and relinearized them, but did not do the calibration > procedure from scratch, only entered the new linearization data. > > Problem: The output is wonderful, and ALMOST perfect. What prevents > it from being perfect is that when I print 21step.tif I see a tiny > discontinuity in the gray ramp, located at a slightly different spot > for each curve (cool, warm, sepia, neutral), somewhere between 50% > and 60%. On neutral it is barely visible; on warm, I can spot it with > a quick scan. > > A while back I modified the 2200 dot size transition point in my QTR > code > to be 0.45 when I saw a similar, but far more pronounced, problem using > the Epson UltraChomes. The change made the resulting UltraChrome gray > ramp > absolutely 100% perfectly smooth, without any discontinuity. I'd like > to get to the same place with UltraTones, since I know it is possible. > > Questions: > > - Should I be recalibrating from scratch instead of just relinearizing? > I would think that wouldn't be necessary, otherwise how can we share > curves? I don't think I recalibrated with Carl's UC curves. > > - Might the optimal dot size transition point vary between ink sets on > the same device? I haven't tried changing it yet, but I would be > happy to do so if that's the problem. Simple enough. > > - Is my expectation wrong, that the ramp should be totally smooth? > I have no evidence this is image-affecting, though I could posit an > image in which it might visibly manifest. It would tell me > a lot if, for example, other folks who've been through this said, > "Yeah, that happens, don't sweat it. Shut up & print." Or the > opposite. > > Thanks for all advice. I'm soooo close to nirvana.... > david > > > > > > > > > > > > > ------------------------ Yahoo! Groups Sponsor > ---------------------~--> > Buy Ink Cartridges or Refill Kits for your HP, Epson, Canon or Lexmark > Printer at MyInks.com. Free s/h on orders $50 or more to the US & > Canada. > http://www.c1tracking.com/l.asp?cid=5511 > http://us.click.yahoo.com/mOAaAA/3exGAA/qnsNAA/ucIolB/TM > --------------------------------------------------------------------- > ~-> > > Please visit the Group Homepage to check the Files, Bookmarks, Polls > and other resources as they are often being updated. The page is at: > > http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint > > If you wish to receive no emails or just a daily digest, or you wish > to unsubscribe, please edit your Membership preferences by visiting > this same page. > > Please follow these basic guidelines: > - Include your full name with your message. > - Include the address of your website, if you have one. > - As threads develop, trim off excess portions of earlier messages to > keep them short. > - As the topic of a thread changes remember to change the subject > header. > - Good manners are required at all time. No personal attacks or flames > - Complete your Yahoo profile. > - Before posting a question, search the message archives and the > various resources on the homepage. > > > > > Your use of Yahoo! Groups is subject to > http://docs.yahoo.com/info/terms/ > >
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Re: [Digital BW] QTR/Linux with UltraTones/2200: gray ramp question
2003-11-15 by Carl Schofield
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