Digital BW, The Print

As far as I can determine, the droplet size is not set by DPI.  Colorbyte says (if I recall correctly) that at 2880 on the x800 printers, the droplet size is limited to a single size per line.  At 1440 the droplet size can be differents sizes on the same line.  They don't seem to be much in favor of 2880 profiles, apparently for this reason.  This implies that they are using some internal software to help determine which to use.  If they are doing it, other RIP makers could certainly do it.
   
  Tom Baker

hogarth@snappydsl.net wrote:
  Well, I didn't understand how the printer actually wants to work - that 
is, given a printer resolution, a particular dot size is used by all 
channels. Smallest dots for 2880, bigger dots for lower resolutions. I 
thought Epson meant to use this feature for more than just that.

What I was envisioning (be careful there!) was a driver smart enough to 
use all the dot sizes all the time, and smart enough to determine when a 
given dot size was appropriate. The drivers (Epson, StudioPrint, QTR, 
etc.) seem to be smart enough to run dither patterns and decide how to 
place dots, and which dots to place, to make good smooth tonal 
transitions. I just thought they could do this with dot sizes too, 
because clearly variable dot size has the potential to improve the 
smoothness of tonal transitions, and improve sharpness too. Yet variable 
dot size doesn't appear to be used that way. My bad.

I can see how it would be good to have the biggest dots in the darkest 
regions - to ensure good coverage of the substrate so that no "paper 
white" shows through. As in, better Dmax. This would clearly be easier 
to do with bigger dots since they could more easily overlap if needed. I 
can also see that the smallest dots would be most useful in the lightest 
tones because there you have to have some paper white showing through to 
get those 1% tones.

But I can also see how the ink and coating are going to have a major 
influence on when and where you need to use the big or small dots. Dot 
gain comes to mind. If you have a lot of dot gain, you probably don't 
need the biggest dots to ensure full coverage of the darkest areas. If 
you have less dot gain, you might need the bigger dots. That sort of thing.

It's almost like we need to extend the ICC profiles - to carry 
information like that to help the driver do a good job of picking dot 
sizes as required to get the tonal transitions we want. Before that 
though I want the ICC profiles extended to do a better job of handling 
neutral tones ;-)
--
Bruce Watson



Tyler Boley wrote:

> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, hogarth@... wrote:
> >
> > So... v12 doesn't have a working algorithm to pick which size dot to
> use
> > for each ink then? I would have thought that this is part of what you
> > pay the big bucks for. This information doesn't make me want to lay out
> > the money for the upgrade.
>
> Bruce, I'm not absolutely positive I understand what you mean by such
> an algorithm but if I do, I think it would be extraordinarily complex.
> It would be dependant on the nature of the particular ink, and the
> particular media. There is obvioulsy a built in algorithm that
> transitions from one dot size to the next, probably based on Epsons
> own. You can control which dot size or sizes to use and how much of
> each, per ink. But after playing with this a bit, I can't imagine how
> it could be automated. Too many things have to be seen to decide how
> to proceed, and for mono inks, I'm seeing no need for the larger dot
> sizes at all in the light inks. In fact some media won't handle it.
> I recall a thread some time ago, Roy and a few others were talking
> about the difficulty of partitioning and linearizing multiple K inks
> along with variable dot. I think that's one reason the K7s are best
> used with a 2880 set up. It's only one dot size, the smallest, making
> so many inks easier to deal with. Also, with so many inks dithering in
> and out, I don't see why one would even need variable dot.
> For those less masochistic than I, the standard setup without variable
> dots works very well, as you know, and the old versions do that just
> fine. One step beyond that in v12 would be to set the K to open to the
> large dot size, and maybe the lightest ink start with the smallest,
> and gain some advantage there from the new feature. Other than
> relinearizing, not much tweaking there.
>
> > Any idea how your tweaked quad output would compare to non-tweaked hex-
> > or sep-tone output in terms of print quality? In other words, if I have
> > a hex-tone set available, should I use that rather than going through
> > the pain and effort of tweaking the RIP for quads?
>
> Though I have buried my nose in some K7 output and am very impressed,
> I have none here now for direct comparison. I don't intend to switch
> to it so having it around taunting me would not be healthy.
> I can say this is a step up for quads, subtle though. I sent the
> tweaked dot setup to a very experienced pro friend, and he said he
> made the best quad print he's ever made with it. Would most people see
> that difference, or place a value on it? I think there is no beating
> K7 output for neutral smooth B&W artifact free digital printing on art
> papers that I have seen. I would not expect v12 quads with tweaked
> dots to hold up to K7 under a loup. Without a loup, I don't know. I
> need variable hues, so other considerations come to play.
> I needed v12 for 9800 color, so had to get it anyway. Basically, I'm
> reporting on miniscul obscure issues of interest to me. I hope it
> didn't sound like an ad for the new version.
> Both Roy and John Dean have working K6 setups right now, I think they
> could say more about that quality.
> Too bad we are all so far aprt, bringing everyone together with their
> print and problems would be very informative.
> Tyler



Please visit the Group Homepage to check the Files, and other resources as they are often being updated.

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:
- As threads develop, trim off excess portions of earlier messages to keep them short.
- Good manners are required at all time. No personal attacks or flames. Hostile, aggressive or argumentative users may be removed from the membership without notice.
- Keep your posts and threads related to the group topic of digital B&W printing. Users who persistently make off-topic posts may be removed from the membership.
- By posting on this forum you agree to abide by the group rules and guidelines, and to abide by the actions and decisions of the group Owner and Moderators. See “Group Topic, Rules and Guidelines” in the Files section:
http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/files/

BY PARTICIPATING IN AND/OR POSTING MESSAGES TO THE DIGITAL BW, THE PRINT YAHOO! GROUP YOU EXPRESSLY UNDERSTAND AND AGREE THAT THE “OWNER” AND “MODERATORS” OF DIGITAL BW, THE PRINT YAHOO GROUP SHALL NOT BE LIABLE TO YOU FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL OR EXEMPLARY DAMAGES, INCLUDING BUT NOT LIMITED TO, DAMAGES FOR LOSS OF PROFITS, GOODWILL, USE, DATA OR OTHER INTANGIBLE LOSSES (EVEN IF THE  “OWNER” AND “MODERATORS” OF DIGITAL BW, THE PRINT YAHOO GROUP HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES), RESULTING FROM: (i) THE USE OR THE INABILITY TO USE THE DIGITAL BW, THE PRINT YAHOO GROUP; (ii) UNAUTHORIZED ACCESS TO OR ALTERATION OF YOUR TRANSMISSIONS OR DATA; (iii) STATEMENTS OR CONDUCT OF ANY THIRD PARTY ON THE DIGITAL BW, THE PRINT YAHOO GROUP; OR (iv) ANY OTHER MATTER RELATING TO THE DIGITAL BW, THE PRINT YAHOO GROUP.




  SPONSORED LINKS 
        Digital wedding photography   Learn digital photography   Digital photography college     Digital photography   Digital photography web site   Digital photography course 
    
---------------------------------
  YAHOO! GROUPS LINKS 

    
    Visit your group "DigitalBlackandWhiteThePrint" on the web.
    
    To unsubscribe from this group, send an email to:
 DigitalBlackandWhiteThePrint-unsubscribe@yahoogroups.com
    
    Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. 

    
---------------------------------
  

  



[Non-text portions of this message have been removed]