Digital BW, The Print

To all those that think I jumped down Clayton's throat too aggressively and
that it was a personal attack I apologise.  But I was reacting in particular
to his leading statements (repeated below).  As I noted, this was not at all
what I was saying. Any thoughtful, measured reading of what I wrote would
not lead one to that conclusion.  Nonetheless I should not have been quite
so aggressive.

(If you can't be bothered reading this long post but print from DG20 or any
workspace that isn't GG2.2 and are trying Epson Adv B&W then at least jump
to the last two paragraphs.)

For those who seem to use any such post as a chance to jump on the aesthetic
vs technical bandwagon you are gravely mistaken.  Technical knowledge does
not in any way displace aesthetics in making art (although not everyone
printing B&W need be an "artist").  Technical skill does, however, help one
to express their creative mind.  With greater technical skill you are much
more likely to achieve your artistic expression to your satisfaction.
Measurements also allow us to communicate with each other without ambiguity.
They say nothing about "art" or "artistic ability" and do not hinder them
either.  This isn't about who is smarter.  (I'm sure Michael is far smarter
than me - he can _read_ Aristotle.)  The concepts here aren't even very
difficult.  It's about taking the time to understand them and to then
benefit from that understanding.

It is helpful to know what it means to work in one workspace vs another.
The colour associated with, say, 90% K changes according to the workspace
that gives it meaning.  Look at a step wedge on your display - at the 90%
patch.  Assign GG2.2 to it.  Then assign GG1.8 or DG20.  The colours change
because those same numbers are being given a new meaning, a new colour space
for interpretation.  In all cases 90% K stays 90% K. (If you "convert"
rather than assign then the number changes so that the colour remains the
same.) Printers only react to numbers - they have no knowledge of human
vision and perception.  We work visually (at least most of us do most of the
time - an eye on the info palette is very helpful and people working in
areas where exact colour matching is more important, eg advertising, are
going to be more inclined to work with the numbers on more occasions).  But
we send numbers to the printer. Understanding, even at the most basic level,
that we need to send the right number to the printer to get the right colour
is helpful.

The reaction of Epson's Adv B&W to, say, 90% K for any given workspace is
not up to you. Epson programmed the printer to print a shade of grey for
each possible 8 bit input value.  It has a response to each possible input
number and that is it.  It's useful to understand what that response is.
Epson did provide some controls for tweaking the response of the printer to
each number but those controls are relatively crude compared with the
controls we have in an image editor like PS.  In general you are likely
better off editing the image in the editor and gaining more precise control.

Which parts of your image you decide to place at 90% K or any other % K in
your chosen workspace is entirely up to your artistic desire (or where
you're told to put it if you are working in an environment which doesn't
provide that freedom - a corporate logo may prescribe the shade of grey
used, for example).

Colour management helps us a lot by providing a translation mechanism so
that we need not worry about the numbers as much.  Whatever parts of our
GG2.2 image that we have subjectively placed at 90% K (as defined by GG2.2)
can be converted to the right colour when we change colour space.  Colour
management also has protocols for dealing with the many situations when a
colour or shade of grey can't be rendered in space to which we would like to
convert so that results are still pleasing.  Colour management is a general
case transformation tool - it's intended to be able to handle any and all
colour spaces.  Epson's Adv B&W doesn't use colour management but there is
nothing to say that Epson didn't think about (the narrow case and) the
reaction of their printer to each possible input for ONE given workspace.
In fact it is the far more intelligent thing to do than making it linear to
L* (for example).  They could have, as I suggested, decided that the most
common colour space in use out there today is Adobe RGB and then by default
the most common grey space is likely GG2.2.  The logical thing to do then is
to tailor the response of the printer (which they can do with a remarkable
degree of accuracy for their inks and papers) to produce visually pleasing
results (say, by using the same greyscale axis transforms they use in their
perceptual colour profiles) for all those many people working in the most
popular workspace today.  If they did so, one would expect 95% K to be
printed very close to 100% K (or if you don't like the absolute black then
think 94 and 99) because it's meant to be that way for someone working in
Adobe RGB/GG2.2.

The point of this conversation was to say don't judge whether the printer is
bunching shadows by printing a step wedge and looking at the results.  If
Epson Adv B&W's default settings have been "calibrated" for Adobe RGB/GG 2.2
then you'd expect the 90, 95 and 100 patches to be a lot closer together
than if it had been calibrated for DG20.

As I said above, Epson Adv B&W does not use colour management and its
response is quite likely calibrated for one workspace.  (It may be or may
not be but I'll bet that the thought of DG20 was never entertained for a
nanosecond if at all.)  QTR Create ICC does, though, allow us to plug this
missing gap in Epson's B&W solution.  It allows us to profile the Adv B&W
response (or any other workflow) and to put a general case translation
device between our workspace and the response of the printer (the print
space).  When we use an ICC profile the numbers are converted or changed so
that the printer gets the right number to produce the right colours.  This
is very helpful because it allows separation between us and the numbers.  We
need focus less on what colour is generated by Adv B&W for the 8 bit
equivalent of 90% K because colour management will translate the GG2.2 or
DG20 number to the right number in the print space.  If you can use QTR
Create ICC I highly recommend it.  Roy has made it very flexible with
respect to data input and you need only have a densitometer. (A
spectrophotometer will give you the added ability to soft proof hue.)  If
you can't use QTR Create ICC then it's likely good advice to ensure that you
work in Adobe RGB/GG 2.2 when using Epson Adv B&W.

Of course you can still decide that you don't like the default "Darker"
setting - that's entirely up to you.  But make that judgement not by looking
at a printed step wedge (in which case one would likely expect the black
patches to be bunched at the end) but rather from the results of prints
printed from the GG2.2 workspace - the workspace for which Adv B&W was most
likely calibrated.  (Remember if you are not using colour management your
choice of workspace is very very important.)

If you use a workspace like DG20 (without colour management) then it is not
at all surprising that you wouldn't like the response of Epson's Adv B&W
default settings.  The reason is obvious with a little technical knowledge.
Look at a step wedge on your display.  Assign DG20 to it.  Then assign
GG2.2.  Those same numbers produce much darker 80-95 patches, for example,
in GG2.2 than in DG20.  The numbers are what go to the printer not the
colours you see. (Without colour management there is no translator to
convert the numbers so that the colours don't change.)  Of course the prints
will come out a lot darker than on your display and your shadows will look
blocked up.  But the reason is your lack of use of colour management (now
available via QTR Create ICC) and, given that, your poor choice of a
workspace which doesn't align well with how Epson likely calibrated the
response of the printer!  The table below is useful in making this point
clearer.  It is the lightness (as measured by CIE Lab's L*) ascribed to 80,
85, 90, 95 and 100 K for each of DG20, GG1.8 and GG 2.2:

Workspace   80    85    90    95    100
DG20        30    23    15    5     0
GG1.8       28    21    13    4     0
GG2.2       20    13     6    1     0

So if you look at a patch (or part of your image) that's 85 K in DG20 but
print it with something "calibrated" to Adobe RGB/GG2.2 you can see it's
going to print a lot darker than it looks on screen and furthermore the gap
between it and a 95K patch will be a lot closer than you expect.  There's
nothing wrong with the printer - it's just reacting to the same number.  You
just need to take the time to understand why there's a difference between
what you see on screen and what you see in print and amend your practice to
suit.  Anyone with an image tagged with DG20 (or any other non GG 2.2 space)
now looking to use Epson Adv B&W would likely be well advised to convert
that image file to GG 2.2 prior to printing it (firstly with the default
settings).  That's a far more sensible first step than trying to tweak the
driver settings.


> From: Clayton Jones <cj@...>

> 
> So according to what you are saying, photographers who now do digital
> printing aren't supposed to bring their personal aesthetic judgments
> to the work any more.  Instead we're supposed to plug in the numbers
> and accept what comes out because someone somwhere decided that GG2.2
> is what we're supposed to use and that dark values are supposed to be
> bunched up.  Hogwash!