Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@y..., "Martin Wesley" 
<mwesley250@e...> wrote:
> ----- Original Message -----
> From: "jimhayes361" <jimhayes@j...>
> To: <DigitalBlackandWhiteThePrint@y...>
> Sent: Saturday, July 13, 2002 8:12 AM
> Subject: [Digital BW] Re: My workaround for the PS6 -> PS7 
posterization
> problem...
> 
> 
> > --- In DigitalBlackandWhiteThePrint@y..., "coveylaw" <brad@c...>
> > wrote:
> >
> > > Sounds great, but i don't have PS6-just PS7.
> > > Any thoughts.  I am very frustrated with the posterization and 
it
> > > makes my prints unacceptable.
> > >
> > > btw has anyone tried nik color efex! to convert to b&w?
> >
> > So someone else IS getting posterization.
> >
> > The real answer is to simply have the curves redone by Paul or 
whoever
> > is handy with a spectrophotometer. This is a lot of work for all 
the
> > pritner/OS combos though. The curves should be redone in Adobe98
> > rather than sRGB. I'd respect Paul he he refuses to go through it 
all
> > again.
> 
> Jim,
> 
> Then what would happen to all the people who do not have this 
problem? This
> is something that is showing up in 1 or 2 systems so far, redoing 
the curves
> would only be justified if the problem were universal.

Well, true. We haven't asked everyone to do the test where you do the 
gamma 2.2 to sRGB conversion in each version and write down the 
hitogram mean, SD and median and see if they differ a little. It did 
for all of us involved in the discussion so something is probably 
happening-

OTOH, you would then be right to question whether the amount of 
difference affects the actual print. So far only I and apparently 
coveylaw see a real difference on the print.

But let's say that a good samaritan has lots of time and patience and 
prints out a step wedge in  PS7 AND, and this is important, uses the 
space Adobe98 this time instead of sRGB for his (her) curve 
generation. Now the corrected curves will give the same values as the 
old sRGB curves did in EITHER PS6 or PS7. Therefore it is a useful 
thing to do since 1) the better color space is now used instead, 2) 
the tones are corrected for using the new color space so it matches 
tones when the old sRGB conversion was used, 3) it is indeed more 
universal...everyone can use it, whether in PS6 or PS7 with less error 
in conversion. Whether they had a problem or not originally, it would 
work for everybody, since it now uses Adobe98 space- which gives 
almost identical results in PS6 or PS7 (barring that strange 
microbanding I had and a bit more posterization which so far I haven't 
gone further to investigate).


Should Paul be asked to do the pushups? Only if he wants to. He's done 
alot already for us. And it does depend on how many others are 
affected by the discrepancy how important it is to switch to Adobe98 
officially for all the curves.

 
> 
> >
> > He might be able to do it with a transfer curve, I don't know. He
> > hasn't responded to any posts on or off list from me on this 
topic,
> > unless I missed it.
> >
> > Also, there is still the unresolved issue of whether I get
> > microbanding even using Adobe98 with PS7. I can't test it right 
now
> > any further, as I'm short on ink to squander. My test print also 
still
> > shows just a tiny bit more posterization in PS7 vs PS6 when using
> > Adobe98. And of course the tones are different using this space. 
It's
> > really crying out for a curve tweak.
> 
> I am printing just fine from PS7 on my 1280. No microbanding and the 
quality
> is unchanged from PS6. Any tweak would then give me and everyone 
else
> trouble.

Not if the tweak gave you identical tonal results- just using Adobe98 
instead of sRGB. All I'm saying is keep the output the same, just 
strengthen the reliability of the output by changing the workflow such 
that the conversion is to Adobe98 instead of sRGB. Paul shoots for the 
same step wedge- just with the Adobe98 conversion. In fact, on the MIS 
site he has already done this for the 1270 and a couple of others- and 
the 1280 if used with a MAc, if memory serves.

At least one other person is having trouble, that's why I responded to 
this post.  If you are using sRGB as your conversion space and you try 
a relatively dark print and you have a PC- well then I guess you DON'T 
have a problem, what can I say. 

If then you are happy with things as they are, then sure, keep on 
trukin'. Having mutiple curves, PS versions, and spaces for Paul's 
workflow might get a bit confusing for me though, ie, "try this in PS7 
and if it posterizes try PS6, or, maybe just convert to Adobe98 
instead of sRGB, unless you get banding..."  I'm just after 
standardizing the curves as much as possible, probably to Adobe98, but 
maybe this just isn't possible.


 Why not tweak the curves yourself for your own use?

This is a really good idea, and probably the best advice to give 
anyone using MIS VM with all the variables of paper. I think we can 
fairly say that now just two people are starting to see a new 
variable...using PS6 vs PS7.

But using one's own tweak, the correct values can be arrived at. The 
only problem is it may take quite a bit of trial and error to get the 
tonal changes even. Right now it's easier to just go back and use PS6.

> >
> > Then the other solution is to just use PS6 until the 2200 comes 
out
> > and go for it. That is a big unknown as well.

> 
> BTW, I have seen some B&W 7600 output which uses the same inks as 
the 2200.
> The results are similar to the 2000P. Odd tonal splits and a print 
that is
> fairly neutral in tungsten lighting is yellow/green in daylight. I 
don't
> know if these were good or poor examples of what the machine can do. 
I want
> to see some more but if what I saw is "good" then I doubt you would 
be happy
> with the hue or metamerism.


That is discouraging, you would think that Epson would know they have 
to give everyone else a run for the money...all those $$$ carts should 
print out something worth printing, oh well...thanks for the advance 
opinion Martin. I ordered up a sample print from Blair (tssphoto) and 
I'll have a look for myself too.

> >
> > You could buy an older computer and network it up on the OS of 
your
> > choice with PS6 and dedicate the printer to it. A bit of bother 
there.
> 
> Since I can't duplicate your problem using very similar equipment (I 
think
> the only difference is that you are running Win98SE and I am on Win 
2000), I
> would urge you to continue to look for something in your set-up that 
is not
> quite right.

Yes, I will do that after two weeks or so. Thank you for all your 
generous help in trying to isolate the problem last week or so. I can 
use PS6 for now on my main machine. I don't need to add another 
computer myself. Again, you see, I was only responding to "Coveylaw" 
with possible options- he has MAC OSX I think.
Jim H.
 
> 
> Martin