Date   

One Month Later

Dan Margulis <76270.1033@...>
 

Posts that are not related to color aren't welcome in this group. I would
like to make a brief exception here in view of the circumstances, asking
that there be no replies so that we can get back to imaging.

One month ago today all of our lives were changed irretrievably. As one who
lives in one of the hardest-hit communities, I observe that most of us here
were not terrorized as much as overwhelmed by the enormity of what occurred
and outraged at being members of the same species as those who brought it
about.

Since that time many of us have been suffering from a profound sadness as
we are constantly exposed to persons whose lives have been shattered: not
just those who have lost a loved one, but the vastly greater number who
have lost their homes or their jobs or been bankrupted. A routine visit to
my doctor yesterday wound up with me treating her as much as the other way
around: confronted with patients so disabled by their grief that they can
no longer cope with life, she herself is having difficulty coping.

In the first few days I was as devastated as anyone else, if not more. One
of the biggest factors in my recovery was the extraordinary number of
messages from persons living in other countries, expressing their
solidarity and offering to help in any way. Many of these came from members
of this list. In a time of great sorrow they were a forceful reminder that
we are all citizens of the world, and that the presence of evil in the
world does not diminish the essential goodness of those who live in it.

Because it was not feasible then to respond to every message, now seems
appropriate to express my deepest gratitude--and, I am sure, that of all
others afflicted by the tragedy--to those who sent personal messages of
support at the time they were most needed.

Dan Margulis


Re: UCR vs GCR...or Neither - RAW CMYK?

samarsh@...
 

--- In colortheory@y..., Dan Margulis <76270.1033@c...> wrote:

No, this is traditional UCR, black only appearing where
necessary to
achieve darkness, not to hold neutrality.
For anyone interested - I put together a quick example page.

http://members.ozemail.com.au/~samarsh/ucr_variants.html

This shows the specific separation controls for the Scitex
EverSmart Supreme oXYgen scanning software - including the
dubiously named 'OFF', UCR and GCR options.

Note the alien grey ramp for the OFF setting - which is what we
generally use for inhouse work and trade scans.

In Dans book, there are some images which show the effects of
GCR and total ink limits - which restrict the detail in the
shadows.

I have also included a quick screen shot showing the difference
in the magenta colour sep for a shadow region.

There are also links to low res TIF files of both Photoshops UCR
sep and the CreoScitex sep.

Even though the detail may not show on press, even with our
CTP setup - the OFF setting in the CreoScitex software
produces much more shadow detail in all separations.

As time goes on, I will do more tests - on coloured areas as well
as shadows and neutrals.

This is just to help visually explain my original confusing thread
on the 'off' setting.

Stephen Marsh.


Re: UCR vs GCR

Dan Margulis <76270.1033@...>
 

Ruud writes,

So UCR and GCR both mean the same and are active in the neutrals (the L
axis in Lab).>>

It's clear that there is a lot of misunderstanding of this important topic
on the list so let me try to clarify what the terms mean and why they are
ambiguous.

In RGB, all colors are unique. If you know the values that make a certain
color, there is no other set of RGB values that make the same color. In
CMYK, this is not necessarily true. 120r120g120b is a gray that can only be
produced one way in RGB. The equivalent in CMYK is in the vicinity of 50k,
or of 60c50m50y, or of any mixture of the two: the more black being used,
the less CMY. Therefore, one could have zero black, or 50% black, or 7% or
12.5% or whatever one wants, and still produce the same gray.

The same would be true of almost any color: remove CMY, and you can add
black. Even something as colorful as a face *could* have some black in it,
although it isn't customary. Only a truly saturated color, such as
70c50m0y, could not have black, because in order to add black, you have to
subtract CMY, and there isn't any yellow to subtract.

The basic tradeoffs in a heavier black is that you accept the risk of muddy
reproduction if either black comes down unexpectedly heavily or you don't
have a good handle on what black dot gain is. Also, it's more difficult to
color-correct images in Photoshop when they have a heavier black. As
against that, there will be fewer unwelcome changes in color, and if the
image is going to press, it will be easier to hold in register.

There is a tiny minority of fanatics who hold that one should always print
with as much black as possible (in Photoshop terms, Maximum GCR with
significant UCA). The remainder of the world realizes that all the benefits
of a heavier black are there if one only uses about half that amount in
colored areas. Going further, the majority of experienced CMYK
practitioners, but not all, prefer much less black than even that. This is
where the terminology confusion sets in.

Assume that you are a person who hates the idea of black ink and would just
as soon print entirely in CMY. That sounds like a reasonable philosophy,
but you have to make certain exceptions. Your deepest shadow will be
something like 100c95m95y. That will be too light and too red. So, if you
are sane, you have to add around 50k.

100c95m95y50k, however, is a total inking of 340%, which most printers
won't accept. Therefore, even though you hate black, you are forced to add
more of it here, so that you can lower the other three values and thus get
a lower total ink. Thus, addition of black, removal of the undercolors
(UCR=undercolor removal).

This is why in the type of image discussed by Hector, all the shadow detail
migrates to the black--the CMY channels have to be suppressed because of
the total ink limit.

For most types of printing black only necessarily will appear in dark
neutral colors, as Ruud suggests. However, for poorer types of printing,
such as newspapers, the lower total ink limit will force the use of black
in colors such as navy blue, even if the type of separation is UCR.

There wouldn't be much disagreement as to where the black would absolutely
*have* to appear. The problem is, confining black to only those areas isn't
workable. You wouldn't want to wait until 95c85m85y0k was reached and
*then* start adding black. The gradation in all four inks would be enormous
as the shadows got darker and the job wouldn't be printable. Instead, the
black has to start in areas that are at least slightly lighter so that it
doesn't get so dark so fast. And, of course, there is zero agreement as to
where it should start.

GCR--gray component replacement--means the use of even more black. But
again, nobody agrees as to how much more, where to start it, or how fast to
add it. If the software expresses GCR in a percentage, about all you know
is that 40% will give more black than 35% would. In Photoshop, "Light GCR"
means more black than UCR, and "Medium" means more than light. In practice,
"UCR" and "Light GCR" mean almost the same thing, "Medium" is much stronger
than "Light", and "Heavy" is a bit stronger than "Medium".

The advantages and disadvantages of a heavier black will be most pronounced
in subtle colors. For example, I just created in RGB a typical green for a
leaf, and separated it five different ways. The results are:

UCR: 60c20m81y1k
Light GCR: 59c18m80y2k
Medium GCR: 56c14m77y7k
Heavy GCR: 55c11m76y10k
Maximum GCR: 46c0m69y24k

No matter how heavy the black runs on press, it won't muddy up this color
if you are using UCR or Light GCR. Anything higher is a risk. OTOH, if your
agenda for the image is very subdued colors, having more black will help
insure that nothing goes wrong. In theory, all of these black generations
will give the same result. But as we do not live in a perfect world, in
practice they do not.

Dan Margulis


Re: Why is this (noisy k plate)?

samarsh@...
 

--- In colortheory@y..., APR <amerphoto@i...> wrote:
http://home.netcom.com/~amerphoto/TinType/
http://home.netcom.com/~amerphoto/TinType/tintype.html

The third photo I deleted the CMYK Black channel.
Tintype-3.JPG
APR - Now that I know what an 'old tin type' photo looks like, I
know why the noise etc found it's way into the K plate.

This image is RGB greyscale.

Any move to CMYK will put some of the detail in CMY - and some
in the K channel. Since all tones are neutral, the separation
method is critical in deciding the type of black plate and how
heavy it is.

Say for example you separated with GCR Max K separation type -
if you deleted the K channel 99% of your image would be gone!

The recent thread on UCR and GCR briefly explains all this.
Dans book goes deeper.

Since your image is _totally_ made from neutral RGB values,
how heavy the black plate is will depend on your separation
settings, which I originally asked about - which you did not reply
on. The image you refer to as CMYK is actually RGB, so I still
have no idea of your separation method.

But this probably does not matter.

If you can find a use for separation tricks which help your
retouching or restoration, then use them. I personally would not
convert a g/scale RGB file to an unknown CMYK variant and then
delete the K channel, in the attempt to restore an old damaged
image.

The K plate when specially separated may provide the start for a
good selection mask for retouching in the original RGB...

Dans recent description on using lighten/darken blend modes
and blurring might be good as well, with or without masks. Other
noise filtering might be used as well, such as despeckle,
dustnscratch and median. Smart noise might be added to add
some life after retouching.

The layer options blend if sliders can also mask based on
luminosity - which is really great for quickly blending corrections
into underlying tones, without manual masks. Luminosity layer
blending/masking is very powerful.

Even some of Dans books descreening tricks would help, as in
scanning hires and resampling down, blend modes and filtering
etc.

Good luck in the restoration. Greyscale has less Photoshop
correction options than a damaged full colour original.

Sincerely,

Stephen Marsh.


Re: Nik Sharpener (was:Scanner Training Advice)

Andrew Rodney <andrew@...>
 

on 10/10/01 6:42 AM, effzee@... at effzee@... wrote:

I was wondering if anyone here has used and has an opinion on Nik Sharpener
Pro.
We've been using it a while now because we we're getting huge variations from
user to user in sharpening and some customers had complained. Now, we're all
pretty much in the same ballpark and are getting some superb results, really.
The only
caveat seems to be a shift to yellow in neutral areas, but I cure that but
fading
to luminosity.

It¹s a superb product and produces results that surpass any manual USM
tricks one produces in Photoshop and does selective sharpening with far less
work than trying to do this in Photoshop 6 (by making complex alpha channels
or layer masks). For output sharpening, it is a superb product. You can also
do minor variations by using the Fade option in Photoshop 6 after running
the filter but I usually find that its a bad idea to second guess the
algorithm simply based on visual feedback. I haven¹t seen any such color
shifts with the product.

Andrew Rodney


[Non-text portions of this message have been removed]


Nik Sharpener (was:Scanner Training Advice)

effzee@...
 

From: samarsh@...
Subject: Re: Scanner Training Advice (was: UCR vs GCR...or Neither - RAW CMYK?)

Each time you check a new area of the image, its a new 'max
detail' scan. This can take about 30 seconds just to evaluate the
USM.

Dan wrote to me that Photoshop is better. Now I understand
what he meant.

No matter how many options, or how good the tool - if it is hard
or impractical to use, the results may be poorer than
Photoshops 'poor' USM.
I was wondering if anyone here has used and has an opinion on Nik Sharpener Pro.
We've been using it a while now because we we're getting huge variations from
user to user in sharpening and some customers had complained. Now, we're all
pretty much in the same ballpark and are getting some superb results, really. The only
caveat seems to be a shift to yellow in neutral areas, but I cure that but fading
to luminosity.

Any reason not to be using it? It cost enough...

W. Garabrant
Kulmbach, Germany


Re: Why is this (noisy k plate)?

Hector Davila
 

http://home.netcom.com/~amerphoto/TinType/
http://home.netcom.com/~amerphoto/TinType/tintype.html

The third photo I deleted the CMYK Black channel.
Tintype-3.JPG

samarsh@... wrote:


--- In colortheory@y..., APR <amerphoto@i...> wrote:
Why is this?

I'm just expermenting.
APR, this is where most 'breakthroughs' are made. <g>

I take an old Tin Type photo.
Can you explain? Film or print? Colour or g/scale? An old tin type
photo means nothing to me.

I then adjusted in Lab for contrast.
Have you tried an adjustment layer set to luminosity, or a regular
curve with the fade to luminosity command,or duping the layer
curving then blending in luminosity mode or etc...

I then change to CMYK and
I deleted the Black channel
(since I see a lot of scratches and spots in Black channel)
Usually nose and jpeg artifact reduction/removal is attempted in
the AB channels of LAB, or in RGB/CMYK in a duped layer set to
color blend mode. I like to combine both methods, so the
luminosity of the original is not altered, only colour.

These changes then 'migrate' into the RGB or CMYK channels,
providing cleaner noise reduction than direct removal of noise.

...and all of a sudden 90 percent of scratches and spots are
gone.
It even looks sharper than the original without sharping it.
Also, I see more detail.
I would expect this to be the case for the B or Y channels - not the
K as such...but the CMY inks can really hide artifacts in the K
channel (with a light black GCR or UCR sep). This does not
excuse a messy plate - but the K is a bit different to others.

It would REALLY depend on the image and output.

How is the CMYK conversion performed? What type of built in
setting or profile is in use? What settings, such as BPC etc.


So, why is that?
Why are the scrathces and spots gone?
Why is it more sharper and has more detail.
What is it about removing the black channel that
causes this?
Can you post the original on the web, or email it off list to me?

I then go to Greyscale mode and back to LAB and CMYK curves
to bring back the contrast and blacks.
I personally would not do this in production, but I understand that
you are playing.

I just want to know, what is the Black channel all about?
Basically, CMY do not make a nice solid rich black, but a redish
muddy dark brown. The K black plate adds definition or Key.
There are many ways to produce black, being dependent on
output and image content. The K plate is you biggest enemy and
ally when it comes to four colour print.

Hope this helps,

Stephen Marsh.


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Re: Why is this (noisy k plate)?

samarsh@...
 

--- In colortheory@y..., APR <amerphoto@i...> wrote:
Why is this?

I'm just expermenting.
APR, this is where most 'breakthroughs' are made. <g>

I take an old Tin Type photo.
Can you explain? Film or print? Colour or g/scale? An old tin type
photo means nothing to me.

I then adjusted in Lab for contrast.
Have you tried an adjustment layer set to luminosity, or a regular
curve with the fade to luminosity command,or duping the layer
curving then blending in luminosity mode or etc...

I then change to CMYK and
I deleted the Black channel
(since I see a lot of scratches and spots in Black channel)
Usually nose and jpeg artifact reduction/removal is attempted in
the AB channels of LAB, or in RGB/CMYK in a duped layer set to
color blend mode. I like to combine both methods, so the
luminosity of the original is not altered, only colour.

These changes then 'migrate' into the RGB or CMYK channels,
providing cleaner noise reduction than direct removal of noise.

...and all of a sudden 90 percent of scratches and spots are
gone.
It even looks sharper than the original without sharping it.
Also, I see more detail.
I would expect this to be the case for the B or Y channels - not the
K as such...but the CMY inks can really hide artifacts in the K
channel (with a light black GCR or UCR sep). This does not
excuse a messy plate - but the K is a bit different to others.

It would REALLY depend on the image and output.

How is the CMYK conversion performed? What type of built in
setting or profile is in use? What settings, such as BPC etc.


So, why is that?
Why are the scrathces and spots gone?
Why is it more sharper and has more detail.
What is it about removing the black channel that
causes this?
Can you post the original on the web, or email it off list to me?

I then go to Greyscale mode and back to LAB and CMYK curves
to bring back the contrast and blacks.
I personally would not do this in production, but I understand that
you are playing.

I just want to know, what is the Black channel all about?
Basically, CMY do not make a nice solid rich black, but a redish
muddy dark brown. The K black plate adds definition or Key.
There are many ways to produce black, being dependent on
output and image content. The K plate is you biggest enemy and
ally when it comes to four colour print.

Hope this helps,

Stephen Marsh.


Re: Scanning Class information??

Chris Brown <cb@...>
 

Re. Scanning Class:

I have been seeking out a scanner operator class with no luck (all
that I found are on-site and product-specific classes). I did find one in
the UK but being on the west coast, that's a little further than I care to
travel. I have not seen any such course offered by Sterling-Ledet but am
assuming such information is available to them. I'm hoping for a more
general (if possible) class, and since I am not currently working,
"on-site" is not an option. Hopefully with a class of this type added to my
resume the dry market might dampen up.

Anyway, noticing a new thread in the discussion group as well as your
standing in the education field, I thought I might inquire as to your
knowledge of the availability of any such courses. Any information and/or
recommendations of such courses would be appreciated.
Try posting your questions and queries on ScanHi-End@...

Although the discussions can get equipment-specific, I have found answers to
most of my film scanning questions, from oil mountnig film on a drum to
mapping RGB values to a specific output targets. There are even several
software and hardware representatives who read and post on a regular basis.

As for the whole UCR, GCR, UCA discussion, it really helps to talk to actual
press operators. The bigger the press and volume of the printing company,
the better. These people really know why an image might print poorly or
perfectly, if it has too much overall ink, or the sep is (color) biased in
some way, etc.

Chris
@
Chris Brown Photography
http://www.chrisbrownphoto.com
Vox: (217) 356-0540 * Fax: (217) 356-1394


Re: Smooth Skin?

Gordon Pritchard <gordon_pritchard@...>
 

RE: APR wrote:

Thanks everyone for the "Smooth SKin" techniques, I'm now an expert!
==========================

One item that I did not see covered in the thread is the impact of halftone
screening on smooth tones. You may want to investigate round dot (round dots
simply grow larger from highlight to shadow) or even FM screening (esp if
presswork is from CTP). Halftone have an "optical bump" when the dots first
touch in the tone scale. With Euclidean (round - square - round) this
happens at the 50% dot. With elliptical it's split between 40 and 60%. Both
screens have the bump in critical tone areas. Round dot places the optical
bump at 75%. Well into the shadows where it is much less visible. Some
printers also try to use exotic screening strategies to avoid rosettes,
which can also appear as "noisy" tones in critical skin color areas.

thx, gordo


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

Print - dot's what it's about!<


Re: Smooth Skin?

Hector Davila
 

Thanks everyone for the "Smooth SKin" techniques, I'm now an expert!


Why is this?

Hector Davila
 

Why is this?

I'm just expermenting.
I take an old Tin Type photo.
I then adjusted in Lab for contrast.
I then change to CMYK and
I deleted the Black channel
(since I see a lot of scratches and spots in Black channel)
...and all of a sudden 90 percent of scratches and spots are gone.
It even looks sharper than the original without sharping it.
Also, I see more detail.

So, why is that?
Why are the scrathces and spots gone?
Why is it more sharper and has more detail.
What is it about removing the black channel that
causes this?

I then go to Greyscale mode and back to LAB and CMYK curves
to bring back the contrast and blacks.

I just want to know, what is the Black channel all about?
Am I doing something right or wrong?


Thanks,
Hector Davila


Re: Scanner Training Advice

samarsh@...
 

Martin replies:

Sorry, I didn't make myself very clear on this point.

The light source on the flatbeds is extremely critical when it
comes to the
apparent sharpness of the images. IMO the first Scitex and
Scanview flatbeds
produced horrible, oversharpened images. The results from
photographic
prints were pretty much unusable unless the USM was turned
off!

The smallest specs of dust or surface imperfections were
magnified, so your
high quality fibre print ended up looking a real mess.

Scanview have since modified the light source to make it less
focused and
more diffuse -- this cured the problem.
I don't think that things have changed, even on the top of the line
model purchased less than six months ago...

The main pre press guy who does most of the scanning comes
from a traditional background - USM in the scan.

As you and many others have noted, the EverSmart line have a
very crisp 'print' look - even with USM off. I have to agree.
Photographers who output to Lightjets or other contone devices
do not like this effect, and are quite vocal on it.

For transmissive scans, this seems an advantage - but I am
biased towards commercial flatsheet offset.

For transmissive, scaner USM may be OK, but if left to my own
devices I would sharpen reflective prints in Photoshop.

Reflective photo prints really suffer from the USM, they look
crunchy on the monitor - but it's amazing what an equalizer the
halftone screen is - even at 175 lpi using CTP.

The USM control in the scanner does have a good grain control,
plus there is also optical defocusing and then the red, green or
red/green filter combo in the scanner...

I think I will really have to pick the CreoScitex guys brain on the
extended USM functions.


Each time you check a new area of the image, its a new 'max
detail' scan. This can take about 30 seconds just to evaluate
the
USM.
This is similar to our scanner -- we get a general preview that
is fairly
mediocre -- but can choose to scan a portion at final resolution
before
committing the whole image.

Unfortunately you just have to keep a bunch of settings in your
mind --
ColorQuartet allows adjustment of strength, noise, light
contours, dark
contours and contour thresholds. With power comes the
responsibility to
RTFM!
Too true. Thats why it's so easy for many to stick to factory
defaults.

There is a weird table called 'LUT.id' which I cant find any
mention of - but I presume it is something to do with
calibration.

Lut is a look-up-table which is probably used to display your
image on
screen, or convert native Lab data to RGB.
I am familiar with LUT's, as this is our default method for
acquiring CMYK (or perhaps one day the odd RGB) scans.

What I mean is that you can choose two colour modes for the
scan. CMYK or perhaps RGB.

Then there are two real options for scanning into a specific
space or flavour, with a third option being the device link section.

The first option, is the input/output ICC profiles. You can scan
from ref/trans scanner RGB input to other output modes, or raw
scanner space (with or without a tag). This is all ICC driven.

The second option is to use the default RGB or CMYK table
option for separation or colour description. The input is the
default ref/trans RGB input description. This is the old style
format, proprietary CLUT approach. It is also used for the non
ICC Scitex monitor calibration/colour matching tool - since these
tables are out of the ICC softproofing link.

This 'table' section has the second option with the lable 'LUT.id'.

I recall reading somewhere online, but cant find where - that this
is used in ICC scanning or something...either IT8 scanning or
perhaps raw untoned high bit editing.

Either way, it probably is not a concern for us.

This LUT.id provides a very flat, untoned image. But I guess it
has a use - I can sleep till I find out on the training day.


There are also 'device link profiles' which are a proprietary
combination of tables/profiles/scanner settings which are
presaved into a 'profile'.

This does not seem to be a true ICC profile - but a proprietary
one.
Proprietory always bothers me -- which is why we don't buy
much Scitex kit.
This is true, up to a point - but I think times are changing.
Perhpas the Lino approach is giving them some competition.

The eversmart uses LS or luminance/saturation curves - but LAB
is not an option that I know of - even with ICC profiles. I dont have
a LAB ICC profile, only an old Kodak CM 'precision transform' file
which does not show up. So they are not directly going after the
Lino method of using LCH editing.

The proprietary issue for me is the default CMYK table - which is
fantastic for most work. This gives much better colour than the
ICC options - but not detail in some cases.

It is my guess that this is a gamut compression issue - or lack of
it. The default tables we like would use relcol rendering, so this
probably accounts for the lack of detail in some tough originals.

We rarely (never) scan in ICC mode, or as RGB and convert in
Photoshop - which does have certain benefits for certain
images.

The 'Device Link Profiles' in question are proprietary - but only in
the sense that they are a scanner preset.

You can choose default tables or ICC methods describing your
RGB or CMYK scans - the device link profile is just a package for
holding these proprietary or ICC settings along with scanner
functions such as endpoints, gradation, USM etc.

The problem is that some of this is ICC, some is scanner
specific - all bundled up in a proprietary file. The confusion in my
mind is the word 'profile' - not all profiles are ICC profiles.
CreoScitex use the term, which creates confusion since the only
other option for defining RGB or CMYK is through ICC profiles,
with or wthout the use of these specific scanner settings.

One thing that I find amusing is how beauty is in the eye of the
beholder. I have read comments from noted ICC proponents on
other lists that they would not use the CreoScitex gear because
of how poorly it handles CM (or used to).

My problems are more petty.

If you do a full bed preview of many originals - before making
your various crops/scans you can only set the crops at this
postage size preview.

After you do an aptly named 'crop preview' - there is no way to
fine tune the crop, which must be done in Photoshop.

This way you are forced to overshoot, so that critical edge content
is not missed. But this is a workflow issue, the scanner is
designed for premounting of originals on registration pin
punched sheets - and the scanner automatically scans and
crops out the pre configured mask window positions.

If you do not have the image rotated correctly - there is no way to
do this in scanner software, only mirroring. You have to rotate the
image in Photoshop.

The prosumer Umax MagicScan software that I used to use did
all this and more. At least software can be upgraded, if
CreoScitex ever get a clue.

And one final observation which really amuses me - and is
probably why some pundits hate the scanner/software:

There is no histogram display (sorry to mention the H word Dan)
<g>

I find the Leaf approach of mapping a simple three point curve
over a histogram interesting...it would make some levels users
more comfortable using curves.

The EverSmart softwares curve control has a nice feature which
is on my wish list for Photoshop - a diagonal reference line is
always dispayed.

This lets you quickly visually judge exactly how steep the curve is
in relation to neutral, as well as bringing the curve back to true in
the midtones and shadows, while you tweak the quartertones
(for example). Such a simple visual aid is very, very nice - and
seems obvious for Photoshop in hindsight.

Sincerely,

Stephen Marsh.


Re: Scanner Training Advice (was: UCR vs GCR...or Neither - RAW CMYK?)

Martin Orpen <orpy@...>
 

on 9/10/01 1:39 pm, samarsh@... at samarsh@... wrote:

4. Black and white prints. Take one of these along as a test of
the
scanner's light source.
Are you referring to native scanner RGB grey balance?
Sorry, I didn't make myself very clear on this point.

The light source on the flatbeds is extremely critical when it comes to the
apparent sharpness of the images. IMO the first Scitex and Scanview flatbeds
produced horrible, oversharpened images. The results from photographic
prints were pretty much unusable unless the USM was turned off!

The smallest specs of dust or surface imperfections were magnified, so your
high quality fibre print ended up looking a real mess.

Scanview have since modified the light source to make it less focused and
more diffuse -- this cured the problem.


Each time you check a new area of the image, its a new 'max
detail' scan. This can take about 30 seconds just to evaluate the
USM.
This is similar to our scanner -- we get a general preview that is fairly
mediocre -- but can choose to scan a portion at final resolution before
committing the whole image.

Unfortunately you just have to keep a bunch of settings in your mind --
ColorQuartet allows adjustment of strength, noise, light contours, dark
contours and contour thresholds. With power comes the responsibility to
RTFM!

There is a weird table called 'LUT.id' which I cant find any
mention of - but I presume it is something to do with calibration.
Lut is a look-up-table which is probably used to display your image on
screen, or convert native Lab data to RGB.


There are also 'device link profiles' which are a proprietary
combination of tables/profiles/scanner settings which are
presaved into a 'profile'.

This does not seem to be a true ICC profile - but a proprietary
one.
Proprietory always bothers me -- which is why we don't buy much Scitex kit.

--
Martin
Idea Digital Imaging Ltd - the "image" specialists
http://www.idea-digital.com


Scanner Training Advice (was: UCR vs GCR...or Neither - RAW CMYK?)

Dan Margulis <76270.1033@...>
 

Stephen writes,

I was wondering if you and perhaps the list have any thoughts on
how I could maximise the training. I know many on this list attend
specific training or seminars - are there any tips from all those
people who have 'been there - done that'.>>

As one who's been to a *lot* of scanner training, let me suggest that
everything depends on the instructor. They range in my experience from
highly qualified and insightful to total baboons. It's well worth your
while to insist on speaking to the instructor in advance to find out what
kind of person you can expect. Often you'll find that the individual has
certain experience that you can really mine. If the person has been a
professional scanner operator, plan on spending a lot of time discussing
techniques for specific originals, but don't expect more than a book
recitation of what the conversion software does. Similarly if the person is
a software geek you may be able to go in depth in that area. And if your
impression is that the instructor is as dumb as a sack of rocks, just go
with a fixed itinerary of things you need to see and hope for the best.

Also: re the forwarded question about open-to-the-public scanner training:
I'm not aware of that kind of training being available anywhere, but that
doesn't mean it doesn't exist.

Dan Margulis


Re: Scanning Class information??

samarsh@...
 

I have been seeking out a scanner operator class with no
luck (all
that I found are on-site and product-specific classes). I did find
one in
the UK but being on the west coast, that's a little further than I
care to
travel. I have not seen any such course offered by
Sterling-Ledet but am
assuming such information is available to them. I'm hoping for
a more
general (if possible) class, and since I am not currently
working,
"on-site" is not an option. Hopefully with a class of this type
added to my
resume the dry market might dampen up.
If you have attended one of Dan's colour correction workshops -
then I presume that you are at a certain level of experience in pre
press or photography etc. One would not presume that you are
rank amateur (unless you had generous employers or some
spare money to throw around).

This should be a good thing to note on the resume.

Now I guess that you are not referring to traditional horizontal
PMT drum scanning.

In Australia, graphic repro apprentices specialised in this field
and learned the craft over a four year period - from experienced
and knowledgeable tradespersons.

If you are talking of high to medium end flatbed scanning, then
this would not require the same sort of background.

There is not much in the hardware side to learn. Cleaning
originals is not rocket science. Mounting originals is usually very
straight forward as well. Some flatbeds have oil mounts, and I
have heard of some custom hacks as well - but this is not the
norm for most flatbed users. Oil/gel mounting is messy and
requires more time and work, but the results are probably worth
it...when I think of how much spotting time this removes - not to
mention much better transmissive scans.

What is left is learning the controls of the scanners software and
how they apply to various originals etc - and how to edit by the
numbers or visually with ICC or other methods.

So without devaluating the whole art of scanning too much - if
you are proficient with Photoshop, RGB, LAB and CMYK editing
and have broad production experience in print or imaging etc,
then most of the learning curve is probably covered.

It would depend on the setting you were aiming for...

A traditional by the numbers scanner operator whose main
concern is CMYK and print is one type user employers are after.

An ICC fluent operator who knows RGB and colour management
and scans raw, flat untoned high bit images for high bit editing in
Photoshop for archival is another position.

Even though both are scanner operators - they have very different
outlooks and experience. This is not to say that they are mutually
exclusive.

Since clients do their own scans these days - professional
scanning is more a side issue, for most shops.

As you rightly state - another skill can be a big asset to your
employability.

If my hunch is right about your experience, you are probably most
of the way there now - even if you have not used a scanner.

I can supply some links off list if you would like, which may be of
help.

Regards,

Stephen Marsh.


Re: Scanner Training Advice (was: UCR vs GCR...or Neither - RAW CMYK?)

samarsh@...
 

I originally wrote:

I was wondering if you and perhaps the list have any
thoughts on
how I could maximise the training. I know many on this list
attend
specific training or seminars - are there any tips from all
those
people who have 'been there - done that'.
Martin replies:

I have no experience of CreoScitex training (apart from
LeafCapture on the
Volare camera). However, I have been to a number of scanner
demos and would
offer the following advice:
Thanks for the reply Martin. So, did the LEAF training simply take
you through the printed exercise book, using the half dozen or so
examples or whatever?

I have a gut feeling that my training will not be too extreme.


Take your own originals rather than allowing the
demonstrators to use their
own standard demonstration images. This will enable you to
see how the
demonstrator copes with an image from scratch rather than
have them rattle
through a set routine that they have no doubt done hundreds of
times before.
Very good point.

The scanner comes with some exercise originals...

Trannys, negs, colour reflective, BW ref, Halftone print.

I presume that these will be used, in conjunction with the
exercises which I have used in the manual anyway...but I will see
on the day I guess.

Make sure that your originals are tough scanning propositions,
for example:

1. An *arty* image that has no natural looking highlight,
shadow or gray
midtones. One that has been shot using coloured gels with
vibrant RGB
colours. This should demonstrate how well the demonstrator
can cope with
numbers only -- or whether the scanning software has profiles
for standard
film stocks.
Yes this is a good test, and all the supplied scanner exercise
images do have endpoints...


2. A tranny that has had a hard life. See how the demonstrators
cope with
scratched and pitted originals. If the demo is on drum
scanners then oil
mounting will fill in most of the damage. If it's on a flatbed is it
still
possible to oil mount?
The EverSmart Supreme can oil mount - but this is optional.

CreoScitex also offer an optional Photoshop plug to help
automate dust/scratch removal.

But this would be very good to see, since this scanner seems
very unforgiving of originals quality (also the six surfaces in
scanning trans can be a real dust spotting problem).


3. Under- and over-exposed transparencies. Take one of each
and see how the
demonstrator and scanner hardware cope with pulling out
shadow and highlight
detail.
The range of this scanner is very good, not drum but very very
good.


4. Black and white prints. Take one of these along as a test of
the
scanner's light source.
Are you referring to native scanner RGB grey balance?

I did a test using a Kodak Greyscale - and each patch was within
one or two RGB points of each other, all over the scale. This
scanner, with nothing more than a canned profile - is near grey
linear balanced. It is so close to R=G=B - but you expect that for
the insane price tag!


5. A negative. Don't know what CreoScitex's position on
negative is? Most
conventional repro houses refuse to go anywhere near them. If
the software
is able to produce positives from neg, watch the adjustments
that the
demonstrator carries out.
It's a bit like getting a poor RGB, with no profile. Most repro
places would not like to go near these too!

The scanner has various neg tables for filmtype makes/models -
and this may help up to a point, but is not a holy grail (too many
variables for canned profiles).

It is all memory colours.

This is a strength of CMYK by the numbers editing.

I will attempt to push for this, as I have not got around to playing
with the supplied exercise neg yet. I have inverted/removed the
orange mask before using Photoshop - but not in the scanner,
on raw data before the image is finally acquired.


While your originals are being scanned, take a detailed look at
the USM
functions of the scanner software. Scanner USM is usually far
superior to
Photoshop. However, this usually leads to a fairly complicated
interface
that you tend to forget after the demo and switch to "auto" when
you get
back to the shop :-)
The controls for USM are very good, and you can even use filters
in the scan.

The big drawback is that the scanner does not do this on a live
interactive way.

You change the setting, then perform a new hi res prescan of the
selected area.

Each time you check a new area of the image, its a new 'max
detail' scan. This can take about 30 seconds just to evaluate the
USM.

Dan wrote to me that Photoshop is better. Now I understand
what he meant.

No matter how many options, or how good the tool - if it is hard
or impractical to use, the results may be poorer than
Photoshops 'poor' USM.

Likewise, with the separation settings, the scanner
manufacturers usually
tell you that profile x is best for this and profile y for that. Get as
much
information on the profiles as you can. Find out how easy it is
to edit the
CMYK profiles and whether the same profiles can be used in
Photoshop.
It is my guess that the basic CMYK table will be used.

I will PUSH for an explanation of their crazy OFF/UCR/GCR
function.

There is a weird table called 'LUT.id' which I cant find any
mention of - but I presume it is something to do with calibration.

All other files are true ICC profiles for input/output.

There are also 'device link profiles' which are a proprietary
combination of tables/profiles/scanner settings which are
presaved into a 'profile'.

This does not seem to be a true ICC profile - but a proprietary
one.

It is my guess that ICC scanning, RGB output and the tabled
DT/SOOM will be ignored...but again I will shortly see this for
myself.

That should be plenty for one day!
Martin, you have helped me more than you can know - and with
luck others as well. Cheers!

Stephen Marsh.


Re: Scanner Training Advice (was: UCR vs GCR...or Neither - RAW CMYK?)

Martin Orpen <orpy@...>
 

I was wondering if you and perhaps the list have any thoughts on
how I could maximise the training. I know many on this list attend
specific training or seminars - are there any tips from all those
people who have 'been there - done that'.
I have no experience of CreoScitex training (apart from LeafCapture on the
Volare camera). However, I have been to a number of scanner demos and would
offer the following advice:

Take your own originals rather than allowing the demonstrators to use their
own standard demonstration images. This will enable you to see how the
demonstrator copes with an image from scratch rather than have them rattle
through a set routine that they have no doubt done hundreds of times before.

Make sure that your originals are tough scanning propositions, for example:

1. An *arty* image that has no natural looking highlight, shadow or gray
midtones. One that has been shot using coloured gels with vibrant RGB
colours. This should demonstrate how well the demonstrator can cope with
numbers only -- or whether the scanning software has profiles for standard
film stocks.

2. A tranny that has had a hard life. See how the demonstrators cope with
scratched and pitted originals. If the demo is on drum scanners then oil
mounting will fill in most of the damage. If it's on a flatbed is it still
possible to oil mount?

3. Under- and over-exposed transparencies. Take one of each and see how the
demonstrator and scanner hardware cope with pulling out shadow and highlight
detail.

4. Black and white prints. Take one of these along as a test of the
scanner's light source. Some scanners have real problems with dust and
surface imperfections on prints. You can do the scan in 5 minutes, but then
have to spend an hour removing the blemishes.

5. A negative. Don't know what CreoScitex's position on negative is? Most
conventional repro houses refuse to go anywhere near them. If the software
is able to produce positives from neg, watch the adjustments that the
demonstrator carries out.

Large format negatives and positives are also ideal for spotting
deficiencies on CCD scanners. In particular, check for banding artefacts in
blue skies or red sunsets. If you see these, then you know that your scanner
is using Kodak's last generation of 10K CCD chips. The banding is caused by
connecting wires which run beneath the red and blue colour filters. Kodak
recently redesigned their CCDs -- but most scanner manufacturers are still
using stockpiles of the older model.


While your originals are being scanned, take a detailed look at the USM
functions of the scanner software. Scanner USM is usually far superior to
Photoshop. However, this usually leads to a fairly complicated interface
that you tend to forget after the demo and switch to "auto" when you get
back to the shop :-)

Likewise, with the separation settings, the scanner manufacturers usually
tell you that profile x is best for this and profile y for that. Get as much
information on the profiles as you can. Find out how easy it is to edit the
CMYK profiles and whether the same profiles can be used in Photoshop.

That should be plenty for one day!

--
Martin
Idea Digital Imaging Ltd - the "image" specialists
http://www.idea-digital.com


Smooth Skin?

Dan Margulis <76270.1033@...>
 

Hector Davila writes,

What's the best way to smooth skin on photos?
I've seen *those* web sites where the girls skin looks real smooth.
How do you do that? Is it bluring AB channels?>>

A method that I illustrated at Seybold is similar to the ones mentioned
previously by Lee Varis and John Opitz, but I think is a little better in
avoiding the overly airbrushed look.

1) Make four identical layers. Layer 1 remains untouched.

2) On Layer 2, Gaussian blur, Radius 2.0 (for starters, may adjust).

3) Having blurred Layer 2, apply a curve that lightens the midtone very
slightly.

4) Change layering mode on Layer 2 to Darken. This will disallow most of
the layer because of Step 3, and will only fill in small white blotches.

5) On Layer 3, apply Gaussian blur at double the radius of Step 2. (Reason:
darker spots on the skin tend to be larger than white spots).

6) Having blurred Layer 3, apply a curve that darkens the midtone very
slightly.

7) Change layering mode on Layer three to Lighten. This will disallow most
of the layer because of Step 6, and will only correct age spots and other
dark blemishes.

8) Compare Layer 3 to Layer 4 (an untouched original) and merge the two as
desired with a layer mask.

This, incidentally, is how one "unsharpens" a picture, when a client has
been so helpful as to supply something that's been oversharpened, without
giving us access to the original.

Dan Margulis


Scanning Class information??

Dan Margulis <76270.1033@...>
 

This individual has previously taken my ACT course.

Dan Margulis

--------------- Forwarded Message ---------------

To: Dan Margulis, 76270,1033
Date: Mon, Oct 8, 2001, 3:24 PM

RE: Class information

Dear Dan,

Although I have been following all threads with interest, I don't
think this note would be of interest to the discussion group. Having never
posted anything anywhere online before (just shy I guess) I am working on
the assumption that this question is too specific for the group.

I have been seeking out a scanner operator class with no luck (all
that I found are on-site and product-specific classes). I did find one in
the UK but being on the west coast, that's a little further than I care to
travel. I have not seen any such course offered by Sterling-Ledet but am
assuming such information is available to them. I'm hoping for a more
general (if possible) class, and since I am not currently working,
"on-site" is not an option. Hopefully with a class of this type added to my
resume the dry market might dampen up.

Anyway, noticing a new thread in the discussion group as well as your
standing in the education field, I thought I might inquire as to your
knowledge of the availability of any such courses. Any information and/or
recommendations of such courses would be appreciated.

Regards,