More Advanced Workflow....

OK Experts -

When I follow the advanced workflow suggestions what am I aiming for?

Am I trying to make the preview of the unexposed area of film black or
neutral? Do I alter the colour settings or should they be set to
none?

Should the following frames then be scanned with no further
alterations or should the colour balnce be further tweaked?

To amplify I have a negative of a person in front of a white wall with
a black painting on it & I can't seem to produce an acceptable scan
(although the film has been processed & printed ok by a lab). My
scans produce unacceptable posterization in the black painting and the
person although teh white seems ok.

After trying the Advanced workflow suggestions the preview of the neg
was a muddy grey.....

Daska

The advanced workflow suggesions deal only with the orange color-cast of
negative film.

You can adjust black and white settings afterwords in Vuescan, but I prefer
doing that in in my graphics program, in my case Photoshop.

Maris

Daska H wrote:
> OK Experts -
>
> When I follow the advanced workflow suggestions what am I aiming for?
>
> Am I trying to make the preview of the unexposed area of film black or
> neutral? Do I alter the colour settings or should they be set to
> none?
>
> Should the following frames then be scanned with no further
> alterations or should the colour balnce be further tweaked?
>
> To amplify I have a negative of a person in front of a white wall with
> a black painting on it & I can't seem to produce an acceptable scan
> (although the film has been processed & printed ok by a lab). My
> scans produce unacceptable posterization in the black painting and the
> person although teh white seems ok.
>
> After trying the Advanced workflow suggestions the preview of the neg
> was a muddy grey.....
>
> Daska


---
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"Maris V. Lidaka Sr." <nemlidaka@ameritech.net> wrote:
> The advanced workflow suggesions deal only with the orange color-cast of
> negative film.

They also deal with the film base of black/white negative film.

Regards,
Ed Hamrick

"Ed Hamrick" <usenet@hamrick.com> wrote in message news:<c0284o$qsg$1@ngspool-d02.news.aol.com>...
> "Maris V. Lidaka Sr." <nemlidaka@ameritech.net> wrote:
> > The advanced workflow suggesions deal only with the orange color-cast of
> > negative film.
>
> They also deal with the film base of black/white negative film.
>
> Regards,
> Ed Hamrick

Thank you both for respinding.

Actually the film is colour even though the image is mainly b/w...

But, still struggling with advanced workflow -

How do I know when I have the correct settings for the advanced
workflow -
what should the preview look like ? Mid grey, grainy grey? and is
there a way I can check?

Am currently doing the following:

finding unexposed section of film -
preview
crop
media type/col neg
color/color balance - auto levels
black point 0
white point 0
Brightness 1
red 1
green 1
blue 1
Neg vendor - Generic
Lock exposure
Preview again
Lock exposure film base color

The use these settings as a base before tweaking for optimum color
balance for each frame.

But am still sometimes finding that my histograms in photoshop are
clipped both ends & images show posterization.

Am I missing something here?

Would be grateful for advice.

Hi, I'm doing just the same thing - trying to improve the scanning
productivity with the advanced flow. My major problem is the color
cast which isn't eliminated anyway.

But maybe I know the answer to your problem: you are using "Auto
levels" color balance, which by its ("classic") definition crops
brightest and darkest areas.

Regards,
Oleg.

daska@thal.co.uk (Daska H) wrote in message news:<62ac1f9d.0402080443.2a394d27@posting.google.com>...
> "Ed Hamrick" <usenet@hamrick.com> wrote in message news:<c0284o$qsg$1@ngspool-d02.news.aol.com>...
> > "Maris V. Lidaka Sr." <nemlidaka@ameritech.net> wrote:
> > > The advanced workflow suggesions deal only with the orange color-cast of
> > > negative film.
> >
> > They also deal with the film base of black/white negative film.
> >
> > Regards,
> > Ed Hamrick
>
> Thank you both for respinding.
>
> Actually the film is colour even though the image is mainly b/w...
>
> But, still struggling with advanced workflow -
>
> How do I know when I have the correct settings for the advanced
> workflow -
> what should the preview look like ? Mid grey, grainy grey? and is
> there a way I can check?
>
> Am currently doing the following:
>
> finding unexposed section of film -
> preview
> crop
> media type/col neg
> color/color balance - auto levels
> black point 0
> white point 0
> Brightness 1
> red 1
> green 1
> blue 1
> Neg vendor - Generic
> Lock exposure
> Preview again
> Lock exposure film base color
>
> The use these settings as a base before tweaking for optimum color
> balance for each frame.
>
> But am still sometimes finding that my histograms in photoshop are
> clipped both ends & images show posterization.
>
> Am I missing something here?
>
> Would be grateful for advice.

Hello, Daska H
you wrote...

> Am currently doing the following:
>
> finding unexposed section of film -
> preview
> crop
> media type/col neg

from here...

> color/color balance - auto levels
> black point 0
> white point 0
> Brightness 1
> red 1
> green 1
> blue 1
> Neg vendor - Generic

....to here all steps are not necessary.

> Lock exposure
> Preview again
> Lock exposure film base color

Advanced workflow is only for getting the right exposure and film base
color values. These values are determined from the raw scanner data and
not affected by color tab settings.

> The use these settings as a base before tweaking for optimum color
> balance for each frame.
>
> But am still sometimes finding that my histograms in photoshop are
> clipped both ends & images show posterization.

To avoid clipping you must set black and white point to 0% or use color
balance none. Some clipping might be caused by film type. Use
'Generic' in this case. A little clipping might be introduced by the
'exposure clipping' value. Set it to 0.0 if you want to be sure to have
no clipping.

BTW: 'Auto Levels' is no good setting to get consistent results. Better
use 'White balance' or 'Neutral'.

May I point you to my tutorials about scanning negatives with vuescan?
(unfortunately still as draft and hard to read - my apologies) There
are three parts. The first one deals with scanning negatives in
gerneral:
http://www.erik-krause.de/tutorial/part1.htm

Details about how to avoid clipping as much as possible you find in
part 3, paragraph 2 'Scanning without Clipping':
http://www.erik-krause.de/tutorial/part3.htm

(the other is part2.htm of course, if anyone wants to read it - critics
for all three are welcome)

--
Erik Krause
Digital contrast problems: http://www.erik-krause.de/contrast

Hello, OlegK
you wrote...

> Hi, I'm doing just the same thing - trying to improve the scanning
> productivity with the advanced flow. My major problem is the color
> cast which isn't eliminated anyway.

You will have to use white point settings and/or neutral color settings
for this task. Film base color is not intended to correct color casts,
it only corrects for a good black (negatives) or a real white (slides).

> But maybe I know the answer to your problem: you are using "Auto
> levels" color balance, which by its ("classic") definition crops
> brightest and darkest areas.

If you set black and white point to 0% it should not crop anything (not
causing clipping). It only adjusts each color channel separately. The
brightest spot in your image will be white for example, no matter what
the color was before...

--
Erik Krause
Digital contrast problems: http://www.erik-krause.de/contrast

Erik Krause <erik.krause@gmx.de> wrote in message news:<MPG.1a9390ac153c84ff98a3b4@ID-18456.user.dfncis.de>...
> Hello, Daska H
> you wrote...
>
> > Am currently doing the following:
> >
> > finding unexposed section of film -
> > preview
> > crop
> > media type/col neg
>
> from here...
>
> > color/color balance - auto levels
> > black point 0
> > white point 0
> > Brightness 1
> > red 1
> > green 1
> > blue 1
> > Neg vendor - Generic
>
> ...to here all steps are not necessary.
>
> > Lock exposure
> > Preview again
> > Lock exposure film base color
>
> Advanced workflow is only for getting the right exposure and film base
> color values. These values are determined from the raw scanner data and
> not affected by color tab settings.
>
> > The use these settings as a base before tweaking for optimum color
> > balance for each frame.
> >
> > But am still sometimes finding that my histograms in photoshop are
> > clipped both ends & images show posterization.
>
> To avoid clipping you must set black and white point to 0% or use color
> balance none. Some clipping might be caused by film type. Use
> 'Generic' in this case. A little clipping might be introduced by the
> 'exposure clipping' value. Set it to 0.0 if you want to be sure to have
> no clipping.
>
> BTW: 'Auto Levels' is no good setting to get consistent results. Better
> use 'White balance' or 'Neutral'.
>
> May I point you to my tutorials about scanning negatives with vuescan?
> (unfortunately still as draft and hard to read - my apologies) There
> are three parts. The first one deals with scanning negatives in
> gerneral:
> http://www.erik-krause.de/tutorial/part1.htm
>
> Details about how to avoid clipping as much as possible you find in
> part 3, paragraph 2 'Scanning without Clipping':
> http://www.erik-krause.de/tutorial/part3.htm
>
> (the other is part2.htm of course, if anyone wants to read it - critics
> for all three are welcome)

Thank you for your response - it seems I was trying to be too
complicated! I will try your suggestions & read your tutorials. AND
get back to you if I still don't understand....

Thank you

Daska

daska@thal.co.uk (Daska H) wrote in message news:<62ac1f9d.0401270340.46d062c4@posting.google.com>...
> OK Experts -

First of all, I do not regard myself as an expert. But I think I do
understand what is happening with your negative of person, painting
and wall and how to correct it. And I think I know what Advanced
Workflow is aiming for. So I'll have my own try at answering and no
doubt the experts will correct me if I am wrong. That could help me as
well as you.
>
> When I follow the advanced workflow suggestions what am I aiming for?

First of all, the purpose of advanced workflow is: (1) to save time by
determining the best compromise exposure for all frames in a roll, not
necessarily the best exposure for each frame; (2) to work out the base
colour of the film from a frame that gives the best chance of doing so
and apply that to the whole roll.

The best compromise exposure might not be as good for another frame as
allowing VueScan to calculate it specifically for that frame. But the
main purpose of the advanced workflow is to save time when scanning a
whole roll without unduly sacrificing quality. So it avoids
calculating exposure from a preview on each frame.

>
> Am I trying to make the preview of the unexposed area of film black or
> neutral? Do I alter the colour settings or should they be set to
> none?

I don't think there is a specific aim here. The purpose is to correct
the film base colour, so getting a neutral colour in the unexposed
area. Whether it is neutral black or neutral grey depends on the
settings for colour balance and black point. But the colour settings
are not relevant to the advanced workflow unless you are also going to
lock the image colour. The aim is just to get a good compromise
exposure and the right film base colour.

>
> Should the following frames then be scanned with no further
> alterations or should the colour balance be further tweaked?

It is likely that colour balance will need to be tweaked. Assuming
that the exposure and film base colour were good, each scan should
have the data necessary to get a good colour balance with individual
adjustment. In my view, this is best done by scanning the film to
create raw files, outputting raw with scan. Then scan from the raw
files and adjust colour balance as required. By the way, as far as I
can see, you can adjust the film base colour (and indeed lock it) when
scanning from the saved raw file so you do not need to get that right
when scanning the film. The exposure affects the raw file but film
base colour does not (and nor do any other colour balance settings).
It affects only the final image.

>
> To amplify I have a negative of a person in front of a white wall with
> a black painting on it & I can't seem to produce an acceptable scan
> (although the film has been processed & printed ok by a lab). My
> scans produce unacceptable posterization in the black painting and the
> person although the white seems ok.

The white wall is a large expanse of dark or black on the negative.
The black painting is a smallish area of relatively unexposed or
slightly exposed film. The person is somewhere between.

Let us first assume you are not using the advanced workflow. You
preview the frame and VueScan calculates the exposure for the whole
frame. It sees the black painting (the nearly clear area of film). It
quite correctly assumes that region contains some detail that it
should not lose. So it does not want the exposure to be so high that
that detail burns out. It sets the exposure low enough to capture the
detail in it. After all, this is what you would want if you were
looking for shadow detail from a scan of a negative. And VueScan does
not know you have a picture of a plain black picture rather than some
interesting shadow!

Right, so it has worked out an exposure low enough to get all that
detail in the black picture. It is too low for you. The white wall
will be fine. That is black on the negative. So reducing the exposure
to a too low value can only see that negative area as even blacker and
make the wall even whiter than white (i.e. it makes no difference to
the white wall). But it has produced detail in the black painting
(light negative) and in the person (quite light negative) that is not
really there. Well, it is there but you don't want to see it. There is
very little difference in magnitude of brightness between the totally
black pixels and the nearly black ones, but there is some difference.
When these differences are mapped to the available display values,
there is a limited choice of such values. So posterization is the
result as the differences go in "steps".

What you need to do is increase the exposure so that the quite dark
areas get completely black and there are no differences to posterize.
So do a preview. Then crop around the person and a bit of the white
wall, not too much, and do not include the black painting. Then lock
the exposure. Then adjust the crop to the whole image and preview
again. The exposure that was locked for person and wall, much higher
than before, will be now applied to the whole image. The black
painting (light on the negative) now gets a high enough exposure to
burn all its detail away and it goes completely black without
posterization. If you have included too much white wall the exposure
might be so high that it now shows unwanted detail in the wall but
since this is so bright, you probably will not see it. And you can get
rid of it by adjusting the white point of the image so clipping it
out.

>
> After trying the Advanced workflow suggestions the preview of the neg
> was a muddy grey.....

This is because (a) the exposure (which was, after all, a compromise),
is still too low for this frame so the black has unwanted grey detail;
(b) the white point is too small for this image so that the white wall
is not really white. Alternatively, when you did advanced workflow,
you might have cropped only on a clear area of film rather than on a
whole frame that included a big clear area. If you did that, the
exposure would be much too low. However, you probably did not do that
as that would not make the white wall muddy.

As I say, I'm no expert but I hope that all makes sense.

Stephen

artbox.srog@virgin.net (Stephen Rogers) wrote in message news:<355e257f.0402120955.367743d0@posting.google.com>...
> daska@thal.co.uk (Daska H) wrote in message news:<62ac1f9d.0401270340.46d062c4@posting.google.com>...
> > OK Experts -
>
> First of all, I do not regard myself as an expert. But I think I do
> understand what is happening with your negative of person, painting
> and wall and how to correct it. And I think I know what Advanced
> Workflow is aiming for. So I'll have my own try at answering and no
> doubt the experts will correct me if I am wrong. That could help me as
> well as you.
> >
> > When I follow the advanced workflow suggestions what am I aiming for?
>
> First of all, the purpose of advanced workflow is: (1) to save time by
> determining the best compromise exposure for all frames in a roll, not
> necessarily the best exposure for each frame; (2) to work out the base
> colour of the film from a frame that gives the best chance of doing so
> and apply that to the whole roll.
>
> The best compromise exposure might not be as good for another frame as
> allowing VueScan to calculate it specifically for that frame. But the
> main purpose of the advanced workflow is to save time when scanning a
> whole roll without unduly sacrificing quality. So it avoids
> calculating exposure from a preview on each frame.
>
> >
> > Am I trying to make the preview of the unexposed area of film black or
> > neutral? Do I alter the colour settings or should they be set to
> > none?
>
> I don't think there is a specific aim here. The purpose is to correct
> the film base colour, so getting a neutral colour in the unexposed
> area. Whether it is neutral black or neutral grey depends on the
> settings for colour balance and black point. But the colour settings
> are not relevant to the advanced workflow unless you are also going to
> lock the image colour. The aim is just to get a good compromise
> exposure and the right film base colour.
>
> >
> > Should the following frames then be scanned with no further
> > alterations or should the colour balance be further tweaked?
>
> It is likely that colour balance will need to be tweaked. Assuming
> that the exposure and film base colour were good, each scan should
> have the data necessary to get a good colour balance with individual
> adjustment. In my view, this is best done by scanning the film to
> create raw files, outputting raw with scan. Then scan from the raw
> files and adjust colour balance as required. By the way, as far as I
> can see, you can adjust the film base colour (and indeed lock it) when
> scanning from the saved raw file so you do not need to get that right
> when scanning the film. The exposure affects the raw file but film
> base colour does not (and nor do any other colour balance settings).
> It affects only the final image.
>
> >
> > To amplify I have a negative of a person in front of a white wall with
> > a black painting on it & I can't seem to produce an acceptable scan
> > (although the film has been processed & printed ok by a lab). My
> > scans produce unacceptable posterization in the black painting and the
> > person although the white seems ok.
>
> The white wall is a large expanse of dark or black on the negative.
> The black painting is a smallish area of relatively unexposed or
> slightly exposed film. The person is somewhere between.
>
> Let us first assume you are not using the advanced workflow. You
> preview the frame and VueScan calculates the exposure for the whole
> frame. It sees the black painting (the nearly clear area of film). It
> quite correctly assumes that region contains some detail that it
> should not lose. So it does not want the exposure to be so high that
> that detail burns out. It sets the exposure low enough to capture the
> detail in it. After all, this is what you would want if you were
> looking for shadow detail from a scan of a negative. And VueScan does
> not know you have a picture of a plain black picture rather than some
> interesting shadow!
>
> Right, so it has worked out an exposure low enough to get all that
> detail in the black picture. It is too low for you. The white wall
> will be fine. That is black on the negative. So reducing the exposure
> to a too low value can only see that negative area as even blacker and
> make the wall even whiter than white (i.e. it makes no difference to
> the white wall). But it has produced detail in the black painting
> (light negative) and in the person (quite light negative) that is not
> really there. Well, it is there but you don't want to see it. There is
> very little difference in magnitude of brightness between the totally
> black pixels and the nearly black ones, but there is some difference.
> When these differences are mapped to the available display values,
> there is a limited choice of such values. So posterization is the
> result as the differences go in "steps".
>
> What you need to do is increase the exposure so that the quite dark
> areas get completely black and there are no differences to posterize.
> So do a preview. Then crop around the person and a bit of the white
> wall, not too much, and do not include the black painting. Then lock
> the exposure. Then adjust the crop to the whole image and preview
> again. The exposure that was locked for person and wall, much higher
> than before, will be now applied to the whole image. The black
> painting (light on the negative) now gets a high enough exposure to
> burn all its detail away and it goes completely black without
> posterization. If you have included too much white wall the exposure
> might be so high that it now shows unwanted detail in the wall but
> since this is so bright, you probably will not see it. And you can get
> rid of it by adjusting the white point of the image so clipping it
> out.
>
> >
> > After trying the Advanced workflow suggestions the preview of the neg
> > was a muddy grey.....
>
> This is because (a) the exposure (which was, after all, a compromise),
> is still too low for this frame so the black has unwanted grey detail;
> (b) the white point is too small for this image so that the white wall
> is not really white. Alternatively, when you did advanced workflow,
> you might have cropped only on a clear area of film rather than on a
> whole frame that included a big clear area. If you did that, the
> exposure would be much too low. However, you probably did not do that
> as that would not make the white wall muddy.
>
> As I say, I'm no expert but I hope that all makes sense.
>
> Stephen


Thank you for your clear and precise explanation - makes perfect sense. A big help.

yours Daska