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Re: Optimal TAC, dotgain for b&w newsprint

samarsh@...
 

Firstly, I know that talking about colour is 'off topic' to this
post,
so I will respond to the original message regarding monotone work.

I have a question for Christine or anyone elese who would care to
comment.

--- In colortheory@egroups.com, Christine Holzmann <tekila@m...>
wrote:

TAC = 260
Black ink limit = 80
I prefer to use UCR for newsprint....you get the skeleton black
plate that way with less muddiness.
Christine, I do both mono & colour news separations each week for
local and city papers - I am hoping to pick the lists collective mind
on this subject, and this seems like a good opening...

No paper we deal with in Sydney seems to offer sep tables or ICC
profiles for their material suppliers. When they do give specs, they
are contradictory or are aimed at the traditional separator or drum
scanner operator.

I am the first to admit that I know just enough to be dangerous, but
to me MEDIUM GCR is not 70% replacement?

As far as I know, Photoshop does not deal in numerical values by
default, it has none, light, medium, heavy and maximum GCR levels.

I guess and presume that none is 0%, light is 25%, medium is 50%,
heavy is 75% and maximum is 100% GCR...I am probably way off base
here, and I'm sure that I will be corrected by those who know better.

For our printers, grey balance and registration seem to be a common
problem - not to mention consistent dot gain.

I commonly use these settings:

SWOP Newsprint 30% Dot Gain
GCR separation type
80% Max Black
230% Max Ink (TIC/TAC/etc)
Heavy Black generation
0% UCA

This cures most registration and colour balance problems, as most of
the neutral tones are in the black plate.

I think that MAX GCR and 30-50% UCA *might* be the answer, but this
is
too radical from my experience to trust to a live job.

I also must have the dot gain wrong, as images still need curves
adjustments to lighten the tones throughout the image - otherwise it
just runs too strong.

Also for a 85-100 lpi screen, I have found that you can sometimes go
as low as 100 ppi when the image is S/S (same size).

Some newspapers use JPEG internally in their FTP, so images get
degraded further, whether you like it or not (but considering the
output, this does not really matter).

Can anyone comment on my choices for colour newsprint work, or give
some rationale to why other settings should be used?

Image content varies, and is too numerous to describe. I realise that
there is no magic 'single setting' for all images, but there must be
some rules to follow (I will shortly purchse Dan's book, as it seems
that the answers to many of my questions will be found there).

Thanks,

Stephen Marsh.


Re: Photoshop 6 question

Dan Margulis <76270.1033@...>
 

Andrew Engelhardt writes,

Maybe I'm not understanding you correctly, but if you click on the "Save"
button while in the CMYK setup dialogue (using the built-in option) you can
save your setup and thus give it a name.>>

That's correct. You have now named the setup and the embedded profile will
reflect that name.

When you open the tagged image file, the mismatch dialogue box will
display the name of your CMYK setup as defined earlier (if you change your
CMYK setup to something else).>>

Yes, it will recognize the profile name, the question is why is the
mismatch box appearing. I've tried several permutations of this and it all
works normally for me (that is, I don't get a mismatch message in PS 6) so
I'd have to suggest looking for something specific to your operation.

Dan Margulis


Printing Overseas

John McKercher <john@...>
 

We are book publishers based in North America and we do some of our colour
book printing in Hong Kong. When we are printing here in North America, we
use Matchprints in order to colour proof our work (which we have been happy
with). At the moment we are not using colour profiling software. We get the
colour we want by using our monitors, our experience and the matchprints
that we run that are fairly close to what we are looking for on press. Often
on press, we end up bumping up the yellow in order to get that "punch" in
the colour that we like for our books.

Our problem is that on the occasions that we have had stuff printed in Hong
Kong, we have been disappointed with our output. We will get our matchprints
looking good on our end, run our film and then ship it for printing. We
explain to the printers that we want them to run heavy on the yellow but it
always seems that our colour is lacking when we get the results. They take
our negs and print from them even though they do most of their printing from
positives and are not that familiar running film and printing from
negatives. Our images are set with the dot gain settings that our printers
have provided us (12%).

Our printers have told us they can provide us with a colour profile for
their presses but they are a Mac shop and we are running PCs so I'm not sure
that their profiles would be of any use to us.

We have asked our printer to provide printed samples and files for these
samples so that we might compare their work on screen to our own and get a
better sense of how we can improve our colour correction to get what we
want. Is there a more accurate way to do this?

We would be happy to produce positives for them to print from but there is
no one here in town that can make matchprints from positive film and we
don't really have the experience with other proofing methods that we could
be sure to trust them.

Is this a case where colour profiling software is the answer, given that our
printer has a profile built to his press? Is there any way I can take their
Mac profile and make it work with Photoshop on the PC (we are using
Photoshop 5) without spending a bundle on profiling software? Or do we need
to find another proofing system?

We would like to go to CTP printing but we are very nervous about not being
able to properly proof our colour.

Thanks in advance,
John McKercher
Hartley & Marks Publishers
john@hartleyandmarks.com


Wavelengths to RGB

alanmartin@...
 

I am trying to find a link between the view of scientists
(the physics of light and the biology and psychology of human
perception of color) and the expertise your members have in
color matching.

More specifically, I am hoping to find a way of matching
physical Hue values (ie the frequency or wavelength of a color)
to the rgb values of a typical monitor.

The Problem
In Photoshop's (and other software's) color pickers, hue values
come in a circle from 0 to 359 "degrees" through 0 again.
From this one can create a linear rainbow spectrum image,
say 800 x 100 pixels, red on the left, violet on the right
and no change vertically.
In the physics lab one can also create a rainbow spectrum of
the range of visible colors.
If you scale these two so their colors match at each end, the
colors in the mid range will not match.
This is like an analogy, in hue, of a gamma matching problem
in brightness.

Here's another way to describe this mismatch:
I am 55 years old so I learned "color theory" at art school
long before desktop computers and Photoshop even existed.
We learned that if you arrange the spectrum in a circle,
green is opposite red, etc.
But in image editing software, cyan (180 degrees) is opposite red
(0 or 359 degrees). The first of these seems truer to my perception,
with green offering the strongest contrast in hue to red.
This may just be early conditioning rather than unbiased perception,
but I doubt it because of what I will term "the Op Art experience":
if you paint equal width stripes of two fairly saturated colors,
with equal brightness, they jazz the eyes (appear to jump around)
most when you choose two colors that are opposites in the
traditional theory rather than the current software model
(ie red-green and orange-blue rather than red-cyan and
green-magenta).

It seems that current software uses this model because it fits
in with the technology: monitors use rgb so they space the pure
r,g,b colors equally round the circle.

That's the background problem.
Here is the practical need I am seeking help with:

For some experiments in human color perception (both normal and
various types of color-blind), I want to create a number of images,
with colors defined in 24bit rgb (the human subjects will see them
on a monitor). Later I shall also make printed images, but that
translation from rgb to cmyk will be less difficult - I shall be
aided by reading the messages in this eGroup no doubt.

The images will include some gradual spectra and also some images
with single-color juxtaposed blocks. In both cases I need to
translate from wavelength or frequency numbers to rgb numbers.
That way I can juxtapose colors which are true harmonics of each
other, in the same way that a major chord in music uses frequencies
with a simple mathematical ratio.
I am not fussy as to the form... it could be just a lookup table,
or an rgb image of a spectrum with markings and wavelength numbers
along the bottom, or even (best of all) a tiny program where you
enter a wavelength or frequency number and get your rgb numbers
as an answer.
So far my searches on the web have been fruitless. I found an image,
as described, but it was an 8 bit indexed gif (yuk) with only three
wavelengths marked (too crude).

In technical terms, I'd prefer the spectrum images to be logarithmic
rather than linear. But don't worry if that sounds too complicated;
almost any source would be better than what I have found so far!

Sorry to bother you with a query that's way off your usual subject
matter!

Alan Martin alanmartin@one.net.au


Re: Photoshop 6 question

Darren Bernaerdt <darren@...>
 

Chris,

Maybe I'm not understanding you correctly, but if you click on the "Save"
button while in the CMYK setup dialogue (using the built-in option) you can
save your setup and thus give it a name. When you open the tagged image
file, the mismatch dialogue box will display the name of your CMYK setup as
defined earlier (if you change your CMYK setup to something else).

What PS6 doesn't do is recognize that name as being the same, even though
it is the same CMYK setup file created in PS5.0/5.5. Sounds like a bug to
me...

Darren Bernaerdt


Hi all, I have a CMYK table that I created in PS5/5.5 with the "built-in"
model. I loaded this table (saved as a .api) into my CMYK settings in PS6
and now when I open CMYK files created in PS5 I get a profile-mismatch
although the profile name appears the same. Any ideas why?
Photoshop 5 didn't have a way for you to name the built-in settings. So
what it does is it comes up with its own name, and then embeds that into
your CMYK images. When you load it into Photoshop 6 it gets yet a
different name depending on the filename it was saved as from Photoshop 5.


Re: Photoshop 6 question

Chris Murphy <lists@...>
 

Hi all, I have a CMYK table that I created in PS5/5.5 with the "built-in"
model. I loaded this table (saved as a .api) into my CMYK settings in PS6
and now when I open CMYK files created in PS5 I get a profile-mismatch
although the profile name appears the same. Any ideas why?
Photoshop 5 didn't have a way for you to name the built-in settings. So
what it does is it comes up with its own name, and then embeds that into
your CMYK images. When you load it into Photoshop 6 it gets yet a
different name depending on the filename it was saved as from Photoshop 5.

There are a couple of ways to deal with this depending on your workflow:

1.) Let the profile mismatch happen each time and just dismiss it. (i.e.
ignore problem)

2.) After opening and dismissing message; go to Image:Mode:Assign Profile
and Assign your current working space (your loaded profile). Now when you
save the image, the working space profile and name will be embedded in
the image. Next time you open it you won't get a profile mismatch.


There is a more automated way to do this involving AppleScripts (to batch
embed the same profile into a bunch of images) but it would be a lengthy
post to explain this in detail.


Chris Murphy


Photoshop 6 question

Andrew Engelhardt
 

Hi all, I have a CMYK table that I created in PS5/5.5 with the "built-in" model. I loaded this table (saved as a .api) into my CMYK settings in PS6 and now when I open CMYK files created in PS5 I get a profile-mismatch although the profile name appears the same. Any ideas why?

Thx
Andrew Engelhardt
Digital Prepress & Imaging
Marketing Dept.
London Drugs Ltd.
12831 Horseshoe Pl.
Richmond B.C. Canada
V7A 4X5
(604) 272-7602
mailto: aengelhardt@...



old monitor

Dan Margulis <76270.1033@...>
 

Kenji writes,

My older Mitsubishi Diamond Pro monitor seems as if I can't get it
calibrated anymore. The problem is that there is a magenta/red cast in
the shadows and little bit of artifacting in the shadows. The overall
gamma and brightness doesn't allow me to get anywhere near calibrated
these days.It won't go dark enough...it feels too flat and washed out
in the shadows.>>

So?

If you're interested in quality color, you can't rely on your *perception*
of neutrality, which is affected by too many variables. If you look at a
single image, and the shadows seem to you too red, perhaps they in fact are
too red, or perhaps there is something else in the picture that's causing
you to *perceive* that they're too red. So, you don't trust your
perception, you look at the Info palette and find out whether it's really
neutral.

As for the contrast, obviously you are seeing less of it on this monitor.
But the whole purpose of calibrating a monitor is to be able to predict
what an image will eventually look like. Whether it's going to become a
chrome or print on newsprint, it won't match the contrast you see on your
monitor, no matter how good your monitor is. So, everybody makes a mental
adjustment.

So I have two questions. Is it maybe a problem with the video card, or
is it probably the monitor? And is it worth taking it in to a repair
shop? Can they get it anywhere near to being able to use it for digital
photography needs?>>

Based on your description, it seems usable now. Such problems typically are
with the monitor and not the card. As for repairing monitors, this is
generally a losing proposition unless they are under warranty. Monitors are
like people, as they get older more and more things start to go wrong.

Dan Margulis


Questions

gowens01@...
 

Hi Group,

What is the differnece between findin the d-man/d-min on a negative and
setting the white and black point on curves?

Are we seeing any parallax problems with the new digital cameras?

Do the digital cameras use the NTSC work space because of the video
connection? The D1 stats list NTSC/Pat video and the fuji S1 Pro lists
NTSC Video Out.

I hear a lot about the D!. Has anyone had experience with output from
the Fuji S1 Pro?

Gary Owens


Re: Optimal TAC, dotgain for b&w newsprint

Christine Holzmann <tekila@...>
 

David,
I work with newsprint and my color is excellent. When I began with newsprint, I had a LOT of questions to ask about the color and settings and got a lot of very excellent advice from Dan Margulis's book: Professional Photoshop 5.
Anyway, to get to the point, I shall tell you what settings I use and what I have found to be optimum for newsprint. One of the MOST important settings to take into consideration for newsprint is the DOT GAIN.
The standard dot gain I would use would be 34%. I then change over to the curves settings for the dot gain and input the following settings at the 50% point for each plate:
CYAN = 84
MAGENTA = 84
YELLOW = 82
BLACK = 88
(I had calculated my settings according to Dan's advice in one of his columns when Photoshop 5 first came out. Basically, you add "50" to your standard setting of "34" to the CYAN and MAGENTA (50 + 34 = 84), you minus two points from that number for YELLOW (84 - 2 = 82) and then instead for black, ADD 4 points to that number (84 + 4 =88). I am not going to go into an explanation as to why...I am strapped for time right now....:(

TAC = 260
Black ink limit = 80
I prefer to use UCR for newsprint....you get the skeleton black plate that way with less muddiness.

85LPI is perfect.
170dpi is also perfect.
Maximum black....85% percent is good.
Maximum white.......4 or 5% is good. (For color a lot of the time I can "blow out" the hightlights to make it look even better.)

As for the pressman, you are absolutely correct about different pressmen using different methods.......on some days of the week, our paper used to get printed REALLY dark with too much ink while on other days, it was printed a lot lighter. This happened on a regular basis tho' and the way I compensated for it was by adjusting the TAC settings. One the days I knew the paper would be printed darker (which was every Friday) I would set the TAC to 240. On the other days, I would use 260.
Basically now our paper is always printed the same (not the over dark way) so I stick to a TAC setting of 260. So basically, between 240 and 260 would be your optimum range.

Hope I was able to help......it seems tho' that your settings and methods are already great the way they are....:)

Good luck!!

Crissi
___________________________________________

I realize this isn't a color question, but I think some of you may still
have some suggestions.

I've got a job going to press this week that being printed bw on uncoated
newsprint. I'm trying to find out if this is the real cheap grayish
newsprint, or the slightly whiter variety as I type. 85 lpi halftones, so
I'm figuring 170 dpi or lower on resolution at 100percent size.

In the past I've used a maximum black of about 82-85 percent black, and a
maximum white of about 4 percent black (unless it's a specular highlight). I
bring the midtones up about 10-20 percent (a 50 percent patch gets placed
about 40-45 percent).

I've had varying results with these settings, and suspect much has to do
with the fact that they have been printed at different presses. I've already
talked to the printer, and they don't have any idea for settings. Whenever
they have digital files they send them to a local blueprint/service bureau
shop for imaging to paper (not film). The blueprint/service bureau claims
that they don't do any adjustments to the files, and don't want to give out
their clients names (lots of help).

I only do print jobs for newsprint about every other blue moon, so would
appreciate any help from the collective wisdom.

TIA,

David
David Riecks * david@riecks.com 701 W. Washington St * Midwest/Chicago ASMP Champaign, IL 61820 * ph/fax 217-239-FOTO(3686) * http://www.riecks.com/



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--
DIGITAL/GRAPHIC ARTIST
http://www.crissi.com

DESIGN EDITOR @ THE CITIZEN NEWS
http://www.thecitizennews.com


Re: The Wide Wide World of Color

KAB <kbrecken@...>
 

Dave,

My "canned solution" comment was a little harsh, allow me do a little
timely back peddling...

CM isn't exactly an off the shelf solution as I suggested, but many of
the commercial components are often advertised as such by vendors and
service providers.

I find it ironic the technology engineered to put color in the hands of
the creative professional has in fact launched an entire industry
dedicated to demystify the technology that's used demystify color.

My position is simply to promote knowledge before technology, and
encourage individuals to experiment with the process and understand the
issues before adopting a solution.

Respectfully

Kevin,


Kev,

It would be nice if digital color were at least as predictable as
current
Kodak and Fuji chrome films for us photographers. Sounds like a job
for CM
Man to me. If it comes in a can I'll take two. <gg>

Dave King


Optimal TAC, dotgain for b&w newsprint

David Riecks
 

I realize this isn't a color question, but I think some of you may still
have some suggestions.

I've got a job going to press this week that being printed bw on uncoated
newsprint. I'm trying to find out if this is the real cheap grayish
newsprint, or the slightly whiter variety as I type. 85 lpi halftones, so
I'm figuring 170 dpi or lower on resolution at 100percent size.

In the past I've used a maximum black of about 82-85 percent black, and a
maximum white of about 4 percent black (unless it's a specular highlight). I
bring the midtones up about 10-20 percent (a 50 percent patch gets placed
about 40-45 percent).

I've had varying results with these settings, and suspect much has to do
with the fact that they have been printed at different presses. I've already
talked to the printer, and they don't have any idea for settings. Whenever
they have digital files they send them to a local blueprint/service bureau
shop for imaging to paper (not film). The blueprint/service bureau claims
that they don't do any adjustments to the files, and don't want to give out
their clients names (lots of help).

I only do print jobs for newsprint about every other blue moon, so would
appreciate any help from the collective wisdom.

TIA,

David
David Riecks * david@riecks.com
701 W. Washington St * Midwest/Chicago ASMP
Champaign, IL 61820 *
ph/fax 217-239-FOTO(3686) * http://www.riecks.com/


Is it really worth it??

Gordon Pritchard <gordon_pritchard@...>
 

Please note:

1) Chris Murphy is quite correct: consistency is the foundation for print
manufacturing process control. This is one of the reasons people have
adopted CTP as it eliminates variation introduced by intermediary film.

2) With CreoScitex Spectrum halftone proofing there is a choice of media -
both vendor (e.g. Kodak, Imation, Fuji, Dupont) as well as type (e.g. within
Imation media you can choose, Eurocolor, SWOP, Commercial high density).
Proofs are initially set up (the "golden standard") by the chosen proofing
media vendor's technical people to corresspond to their analog (film-based)
equivalent rather than a press sheet. Of course, the Spectrum user does have
the option of building their own standard (with or without the help of the
vendor's technical people) to represent their presswork target.

3) If you are currently printing from film-imaged plates, you can choose to
calibrate your CTP so that the presswork it delivers mimics what you would
have achieved with your film workflow. Therefore your analog proof standard
can be used to represent your CTP standard. We do have some customers who,
for their own reasons, actually generate film only to generate a proof. They
then throw the film away and image direct to plate. Works fine.

thx, gordo

Gordon Pritchard
Commercial Print Specialist
CreoScitex
Vancouver Canada
T: 604.451.2700 ext 2870
C: 604.351.2437
gordon_pritchard@creoscitex.com
http://www.creoscitex.com

Print, the original dot com<

ORIGINAL MESSAGE BELOW:

From: Terence L. Wyse


<Terry Wyse said>:
Now, if you're
going direct-to-plate, all bets are off!
<and then Chris Murphy responded>:
Well no you just have to make some decisions in the right order. If
they
are going to force it to match an existing proofing system, it can be
done within certain limits. If they are going to optimize with the idea
of getting a new digital proofing system they can also go that route.
The
key is process control. CTP or DTP makes no difference. The issue is
consistency or the lack thereof. If there is no consistency then all
bets
are off.

<Terry feels the need to clarify>:
I guess I should've clarified/qualified my "all bets are off" statement in
reference to CTP. What I meant was that with CTP you most likely are not
producing film-based analog proofs so you can't calibrate to and profile
your analog proof, you need something else. At this point I suppose you
could profile a "digital analog"(?) proof such as a Kodak Approval or Creo
Spectrum-type proof but this has most likely been calibrated to match a
press sheet in the first place. If this is the case, you could just go
ahead
and profile the press sheet and be done with it. Most of my point was to
the
somewhat futile and at least very difficult proposition of profiling press
conditions as you yourself have pointed out in the past and using
something
at least a bit more consistent such as an analog proof. Sorry for the
confusion.

Regards,
Terry
_____________________________
Terence (Terry) Wyse
PrePress Specialist
All Systems Integration, Inc.
781.935.3322 voice
781.935.6622 fax
http://www.allsystems.com
terry@allsystems.com
_____________________________


old monitor

Kenji Kerins <kenji@...>
 

My older Mitsubishi Diamond Pro monitor seems as if I can't get it
calibrated anymore. The problem is that there is a magenta/red cast in
the shadows and little bit of artifacting in the shadows. The overall
gamma and brightness doesn't allow me to get anywhere near calibrated
these days.It won't go dark enough...it feels too flat and washed out
in the shadows.

So I have two questions. Is it maybe a problem with the video card, or
is it probably the monitor? And is it worth taking it in to a repair
shop? Can they get it anywhere near to being able to use it for digital
photography needs?

It's tough getting rid of hardware for me, I cling.

TIA,

Kenji


Re: untagged tiff image 300 ppi, Opens at 72 ppi on p.s.6 (John Opitz)

Dave Adams <david.a.adams@...>
 

You can download a FILE FORMAT MODULE from
"http://www.kodak.com/global/en/professional/support/DCS/dcsRegister/downloadIndex.shtml"

This module lets you open a custom TIFF as you would any image
supported by Photshop. There is a Mac and Windows version.
At the link above, you will be required to register your email to gain
access to downlaod pages. You can also download the current firmware
and a new application called PHOTODESK.

wulff.wendelstein@t-online.de wrote:


Andrew wrote re. Kodak DCS files:

"There’s no color info in the file at all; it’s a grayscale file. The
Acquire module is what allows you to actually end up with a real Tiff
or
other color file. "

My "raw" DCS files carry the ending .tif from origin and do open full
res in
PS (Windows), but too dark and with a weird color shift. Indeed only
the
Acquire module seems to render them usable. Trying to correct them in
PS
didn't give me usable results (might be possible though). Is there any
other
known way to open them correctly without the Acquire module? A
profile?

Is there any good reason for Kodak introducing a prorietary "tiff"? I
tried
to find some info about this format, but to no avail.

How do you access the preview tiff? Didn't even know it existed...

Wulff Wendelstein

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Re: untagged tiff image 300 ppi, Opens at 72 ppi on p.s.6 (John Opitz)

Bob Smith <rmsmith@...>
 

wulff.wendelstein@t-online.de wrote:

My "raw" DCS files carry the ending .tif from origin and do open full res in
PS (Windows), but too dark and with a weird color shift. Indeed only the
Acquire module seems to render them usable.
That sounds odd. Are you sure you don't have the DCS format plug-in
installed in Photoshop? On Mac systems its installed along with the acquire
module and allows the Kodak proprietary tiffs to open just as any other file
(without going through the Acquire module) however you don't have any
control over the various parameters that the acquire module gives you. The
image just opens at default settings. Without that plug-in I didn't think a
color image was possible at all. I haven't tried this in ages.

Is there any good reason for Kodak introducing a proprietary "tiff"? I tried
to find some info about this format, but to no avail.
When the file is written to the disk in the camera, space and time needed to
write that file are at a premium. The DCS format just records only the data
of each pixel as captured by the CCD. Therefore each pixel is just one
piece of grayscale data. That's all that the CCD "sees". All color
processing to figure out which of those pixels represent red, green, or
blue; and to interpolate the missing color pixels is done outside of the
camera in the acquire software. That keeps the camera's job simpler and
faster and leaves the major number crunching to the host computer. Writing
a full color TIFF in the camera would really bog down camera performance.
It also causes you to lock in color processing choices at the moment of
photography rather than waiting till later to finalize those decisions.
Nikon D1s can produce finished TIFFs in camera as an option yet I rarely
hear of anyone using it.

Is there any other
known way to open them correctly without the Acquire module?
Kodak just released a new application for editing DCS images without going
through the Photoshop based acquire module. Its called Photo Desk and can
be downloaded from Kodak's site. I know its available at no charge to DCS
camera owners, but I think that others can download it as well.

Bob Smith


Re: untagged tiff image 300 ppi, Opens at 72 ppi on p.s.6 (John Opitz)

Andrew Rodney <andrew@...>
 

on 1/9/01 2:44 AM, wulff.wendelstein@t-online.de at
wulff.wendelstein@t-online.de wrote:

My "raw" DCS files carry the ending .tif from origin and do open full res in
PS (Windows), but too dark and with a weird color shift. Indeed only the
Acquire module seems to render them usable. Trying to correct them in PS
didn't give me usable results (might be possible though). Is there any other
known way to open them correctly without the Acquire module? A profile?
You take the camera files directly from the internal drive and open them?
That's very odd. I've worked with most of the Kodak DCS cameras and have
never seen a full rez color file open this way (as I said, only the tiff
header). The camera is a one shot so it's interpolating the color data
somewhere. It sounds like the dark images are linear files. That means that
the camera software isn't applying any curves which is really ideal for
profiling. Better still, you'd have more than 8 bits pre color in this
linear file. You have this option in the Kodak Acquire module along with
some control over sharpening and such.

Is there any good reason for Kodak introducing a prorietary "tiff"? I tried
to find some info about this format, but to no avail.
Kodak didn't introduce a proprietary Tiff per say. Their raw file format is
a grayscale file because that's how the camera sees. What they did (at least
with all the DCS cameras I've used) was place a tiny Tiff header, a
thumbnail if you will that opens when double clicked on. The idea being that
people that didn't have the Acquire module could at least see a low rez
"preview" of captured images. Getting the high rez file into a full color
mode took some proprietary software (one being the Kodak acquire module)
which produced the actual color.

Andrew Rodney


Re: Is it really worth it??

Terence L. Wyse <terry@...>
 

<Terry Wyse said>:
Now, if you're
going direct-to-plate, all bets are off!
<and then Chris Murphy responded>:
Well no you just have to make some decisions in the right order. If they
are going to force it to match an existing proofing system, it can be
done within certain limits. If they are going to optimize with the idea
of getting a new digital proofing system they can also go that route. The
key is process control. CTP or DTP makes no difference. The issue is
consistency or the lack thereof. If there is no consistency then all bets
are off.

<Terry feels the need to clarify>:
I guess I should've clarified/qualified my "all bets are off" statement in
reference to CTP. What I meant was that with CTP you most likely are not
producing film-based analog proofs so you can't calibrate to and profile
your analog proof, you need something else. At this point I suppose you
could profile a "digital analog"(?) proof such as a Kodak Approval or Creo
Spectrum-type proof but this has most likely been calibrated to match a
press sheet in the first place. If this is the case, you could just go ahead
and profile the press sheet and be done with it. Most of my point was to the
somewhat futile and at least very difficult proposition of profiling press
conditions as you yourself have pointed out in the past and using something
at least a bit more consistent such as an analog proof. Sorry for the
confusion.

Regards,
Terry
_____________________________
Terence (Terry) Wyse
PrePress Specialist
All Systems Integration, Inc.
781.935.3322 voice
781.935.6622 fax
http://www.allsystems.com
terry@allsystems.com
_____________________________


Re: untagged tiff image 300 ppi, Opens at 72 ppi on p.s.6 (John Opitz)

WW
 

Andrew wrote re. Kodak DCS files:

"Theres no color info in the file at all; its a grayscale file. The
Acquire module is what allows you to actually end up with a real Tiff or
other color file. "


My "raw" DCS files carry the ending .tif from origin and do open full res in
PS (Windows), but too dark and with a weird color shift. Indeed only the
Acquire module seems to render them usable. Trying to correct them in PS
didn't give me usable results (might be possible though). Is there any other
known way to open them correctly without the Acquire module? A profile?

Is there any good reason for Kodak introducing a prorietary "tiff"? I tried
to find some info about this format, but to no avail.

How do you access the preview tiff? Didn't even know it existed...


Wulff Wendelstein


Re: The Wide Wide World of Color

Dave King <kingphoto@...>
 

Gorton Pritchard wrote:

If color can be measured then why can't it be "argued, predicted or
directed"?

gordon pritchard
_________________

Gord,

good question,

I think it cant be argued because of visual perception & personal
preference,
outside of the math and numeric's who's to say the sky is blue?, it
might be
purple to some, is the grass green ? and that pumpkin is it red or orange.?

Its simply what the individual that pays the bill sees no plotted target
within any color model described with a numeric breakdown, be it LAB.,
RGB, CMYK or otherwise will change that interpretation

I think it cant be predicted because of that influence and all the other
influences ..day t o day ink set to ink set, device to device pressmen to
pressmen its all a "best guess" "shot in the dark" and "I hope it runs well"
scenario anyone that thinks they have a recipe for perfect color is simply
just not humbled by experience.

It cant be directed because the impacts can't be predicted,

I don't dismiss the technology or the science but with out knowledge and
experience a canned solution be it CM or otherwise is just a lazy shortcut,
just one more buffer behind the real issue surrounding color accuracy and
consistency.


respectfully

Kevin
Kev,

It would be nice if digital color were at least as predictable as current
Kodak and Fuji chrome films for us photographers. Sounds like a job for CM
Man to me. If it comes in a can I'll take two. <gg>

Dave King
Commercial Photography
New York City