Digital BW, The Print

Clayton,

Found your observation about the different dithering settings
interesting.  Keep us posted on your BO curve development too.  Do I
gather that you are considering moving from "BO" to "QTR with BO look"
????  Using QTR, it will no longer be the classic "BO" print, but
rather a QTR version.  Is that correct ?




--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Clayton Jones"
<cj@c...> wrote:
> Hello Ernst,
> 
> >What are the best results with QTR and BO for the different  Dither 
> >Algorithms ?  The effect must be more visible in BO printing and may 
> >vary per printer and paper. I also wonder what looks most alike the 
> >Epson driver in BO mode. Just curious.
> 
> I've been wondering that myself (haven't used QTR much yet, been
> working only with the "Ordered" setting which is slightly
> tighter/smoother than Epson) so your question made me go find out.  On
> a 2200 w/ Eboni and my current QTR BO curve (still under development)
> I printed a step wedge on EEM for each dither setting and compared
> them.  All were with 2880 and "Faster" speed setting (more about that
> below).  Here are the results:
> 
> -----------------------------------------------
> Ordered - smaller patterns of dots than Epson's squigglies, slightly
> tighter pattern, slightly smoother in appearance.
> 
> Adaptive Hybrid - tiny difference in pattern if you look hard for it
> with the loupe, but for eyeball appearance is nearly indistinguishable
> from Ordered.
> 
> Fast - Pretty much same as Adaptive Hybrid, but under the loupe I see
> a tiny bit of dither banding.
> 
> Very Fast - Horrible!  Prints streaks of graphic patterns.
> 
> Hybrid Floyd-Steinberg - Surprise!  Very tight and smooth.  Noticeably
> smoother to the eye compared to Ordered and Epson.
> 
> EvenTone - More surprise.  Ever so slightly smoother than Hybrid FS.
> -----------------------------------------------
> 
> For a more practical test to verify the above, I printed a landscape
> with clouds, an image that has always showed up BO weakest area,
> smooth midtones.  It verified all of the above ramp observations. 
> There is a place in the clouds with little swirling patterns that are
> barely defined in Epson BO, are a tiny bit better with Ordered, and
> are very crisp and clearly defined with HFS and EvenTone, with
> EvenTone being a tiny bit the better of those.
> 
> I am delighted.  This is going to make a huge difference to BO lovers.
>  Just on this one test print I can see it's an enormous improvement,
> with a greatly reduced grainy look and retains the luminance.  Now I
> just need to finish working on the curve.  It's still too blocked up
> at the dark end.  I will post it as soon as it's done, probably over
> the coming weekend.  Wahoo!  Imahappycamper.  Why didn't I try this
> before???!!!!  Still need to test with other papers...
> 
> About the "Speed" setting: I printed a TrueTone ramp with Speed set to
> "Better" (still 2880), and it messed up the ramp, introducing some
> bumps and streaks into what had been a smooth ramp using "Faster"
> 
> 
> Regards,
> Clayton
> 
> 
> Info on black and white digital printing at    
> http://www.cjcom.net/digiprnarts.htm