Digital BW, The Print

Hello Diana;

I tried to restore this thread under its original subject heading and so repeated 
our previous messages below for anyone who wants to follow this. It's easy to 
hit reply and end up with "Digest" as your subject!.... 

I am glad you saw an improvement in your results with the resing-up tip. There 
is continuing development on OPM, with a beta version currently being 
tested for the 2200 (no new features, just tweaks to address some of the 
issues users have reported). Should you buy IJC, you will find that it is 
capable of controlling up to 7 ink channels with smooth spline curves that 
can accept 20+ points each (normally 2 or 3 are plenty). That gives 
unprecedented controll over the amount and combination  of inks to be laid 
down for each digital value in your image file.  As has been discussed here 
before, for the full benefit  you would need a densitometer, but good results 
are also possible by visually comparing your output to a good print of the 
26-step grayscale.

A note about comparing printing software: Comparisons between OPM and 
any other bw printer driver would generally have to assume perfect profiles 
for each, so that the drivers are in fact compared, not the profiles. This gets 
tricky if drivers that rely on canned profiles are fixed to a certain performance, 
while OPM uses custom profiles (made in IJC) that can take into account 
every nuance of your particular set up. This is less of an issue with printers 
like the 2200 using OEM carts, and a bigger problem with CIS-equipped 
desktops and large formats.

I hope you can let us know what you think of the results your are getting.


Antonis


------------------------------------------------------------
Hi Antonis,

I took your advice about rezzing up a file to 720 dpi and changing to 
16 bits and I got MUCH better results with OPM, at least for 1 
particular image with lots of thin strong diagonals. There had been 
noticeable (but fine) stairsteps when the file was 300 dpi and 8 
bits. The same file printed with Roy's QuadToneRIP under OSX didn't 
have the stairstep problems though - maybe his driver can rez up the 
file like the Epson driver.

I think both programs/drivers have alot of potential. I haven't 
purchased Inkjet Control (yet) but the fact that their software lets 
you tweak every ink channel is very nice. With QuadToneRip, you tweak 
4 channels in CMYK mode, regardless of printer model (at least that 
is the case for the 2200 curves). At least with both programs I'm 
seeing no metamerism with the Matte Black ink on EAM and Eclipse 
Satine, whereas the Epson driver always gives me greens and/or 
magentas!

By the way, I have a Mac G4 and am running OPM under OS 9.1. I run 
Roy's QuadToneRIP under OSX 10.4.2.

Diana







--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Antonis Ricos" 
<antonisphoto@y...> wrote:
> Diana,
> 
> I have discovered that some images look sharpest at 720 dpi when printed 
> with OPM  on the 2200. If you open your image in Photoshop and check the 
> resolution it should read 720 dpi. If not, you can res it up using bicubic 
> interpolation. Then try printing again.  
> 
> This may or may not make a big difference in your print depending on how 
> close you were to 720 dpi before you resed up.  It also depends on what 
kind 
> of image it is - how grainy, how sharp, if it has sharp diagonals... etc.
> Also, if you still see problems, it's worth  setting the image to 16 bits and 
> comparing prints.  
> 
> Testing tip:you can crop a small area where a problem shows up and print it 
> over and over on the same sheet with different settings. You set the x,y 
> positions in OPM to avoid overlaps.
> 
> Just to be clear about the 720dpi "preference": It is unrelated to the amount 
of 
> information a scan or digital camera file contains; it has to do with matching  
> pixels-to-dots and driving the printer at its native hardware resolution. The 
> Epson driver (for the 2200 at least) does this interpolation internally, so no 
> matter what res you throw at it, the image will be made to look its "best" as 
far 
> as the printer goes.
> 
> I am very interested in your comparisons between Roy's RIP and OPM - 
> especially since they share some DNA between them ! (and didn't that 
> originate at MIT?....) The tonal gradations in OPM are mostly the result of a 
> particular profile and whether your particular system performs as well as 
mine 
> (since I made the first 2200 profiles).
>  In theory, you are supposed to have IJC and be able to tweak the profiles 
> both for color and for smoothness. This system is really aimed at putting an 
> end to canned profiles of any kind (including its own) ! 
> 
> As we discuss this further, it would help if you mentioned your operating 
> system and other details of your setup.
> 
> If you are experiencing problems with the 2200, you may want to write to 
> bowhaus and see if they will let you try the current beta which has some 
fixes 
> for the 2200. Their email for OPM / IJC is: software@b...
> 
> Antonis
> 
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Diana Park 
> <dip@m...> wrote:
> > Antonis,
> > 
> > I've just started experimenting with OPM on my 2200 and I'm not sure 
> > what you meant below - should the file actually be set to 720 dpi or 
> > should the printer output be set to 720 (as opposed to 1440 or 2880)? 
> > I haven't purchased IJC so I can't control the curves supplied with 
> > OPM but I do like the Blender option where I can mix warm and cool 
> > curves. I've found 70% warm and 30% cool to give a nice neutral (to 
> > my eye) tone.
> > 
> > I've also FINALLY successfully installed Roy Harrington's QuadToneRIP 
> > (many thanks Roy for all your troubleshooting help!) and while his 
> > neutral curve is warmer than the above mix in OPM, the tonal 
> > gradations seem smoother. Now for some curve tweaking!
> > 
> > Diana Park
> > dip@M...
> >