VueScan IR cleaning with Kodachrome slides (Nikon LS-40/IV ED)
Henri Gabriel
I've been having "issues" with IR cleaning of Kodachrome slides.
Across numerous batches, the darker areas of most frames are
"detected" as defects.
As in this example:
http://www.stabbingpain.com/public/vs-ir.htm
In short, is this to be expected?
Thanks much,
Henri
James Robinson
>
> I've been having "issues" with IR cleaning of Kodachrome slides.
> Across numerous batches, the darker areas of most frames are
> "detected" as defects.
Here is what the manufacturer of the software says about Kodachrome. It
should answer your question:
======================================================
In general, Digital ICE works with Kodachrome film. However ASF’s
experience indicates that some Kodachrome images suffer a loss of image
detail as a result of Digital ICE image processing. Any loss of detail
will depend upon the particular Kodachrome film, exposure level, and
image content. Kodachrome slide film uses a unique dye that responds
differently from other slide films. Due to the nature of the dye and the
Kodachrome film development process, Digital ICE can misinterpret
certain image detail as a defect. An example of a general group of
images that can be affected is underwater images due to the lack of
content in the red channel. Similar images in which the green and blue
channels overshadow the red data may present a problem.
=====================================================
http://www.appliedsciencefiction.com/support/Scanners/FilmICEFAQs.shtml#Q8
Graham Russell
either with Vuescan of Nikonscan. Kodachrome does not let IR light through
properly so IR cleaning will not do a very good job. The effect I see using
a LS-4000 is a softening of the image.
To maintain the highest quality I would recommend leaving IR cleaning turned
off and then retouching any spots by hand in Photoshop (of your prefered
editor). This certainly works for me.
Graham.
"Henri Gabriel" <henri...@msn.com> wrote in message
news:c38d8b55.03020...@posting.google.com...
Erik Krause
you wrote...
> > I've been having "issues" with IR cleaning of Kodachrome slides.
> > Across numerous batches, the darker areas of most frames are
> > "detected" as defects.
>
> Here is what the manufacturer of the software says about Kodachrome. It
> should answer your question:
The question was about VueScan infrared clean, not about ICE. The
manufacturer of Vuescan says: "VueScan's infrared cleaning works fine
with Kodachrome. It's only ICE that has a problem with
Kodachrome." ;-)
--
Erik Krause
Digital contrast problems: http://www.erik-krause.de/contrast
Ilkka Paloheimo
> manufacturer of Vuescan says: "VueScan's infrared cleaning works fine
> with Kodachrome. It's only ICE that has a problem with
> Kodachrome." ;-)
Nope. My own experimentation shows that VueScan is not better with
Kodachromes than NikonScan/ICE (LS-4000). Sometimes it works, sometimes it
does not. According ASF that has something to do with IR penetration of
Kodachrome 's cyan layer and the problem is clearly visible with bluish
slides. I've decided to leave ICE off with KR and do dust removal in
Photoshop.
Ilkka
James Robinson
>
> Hi, James Robinson
> >
> > Here is what the manufacturer of the software says about Kodachrome. It
> > should answer your question:
>
> The question was about VueScan infrared clean, not about ICE. The
> manufacturer of Vuescan says: "VueScan's infrared cleaning works fine
> with Kodachrome. It's only ICE that has a problem with
> Kodachrome." ;-)
Yes, I didn't read the subject very closely, and missed that it was
about Vuescan.
However, from the ASF description, I infer that the difficulty with
Kodachrome is a physical problem with the way the scanners see the dyes
in the emulsion. In short, they have difficulty differentiating defects
from some color of dye. I would presume if they could fix it, they
would have already. I therefore suspect that the same problems would
present themselves with either software package.
Jeff
Vuescan's version of ICE is not better than ASF's version. Just take
a kodachrome, do the preview, then look at the IR in the preview.
You'll see that it's all over the image like snow!
Scanners that provide ICE-like capability use infraRed, which simply
doesn't penetrate kodachrome properly, regardless of the driver being
used. The film must be transparent to infraRed, and Kodachrome isn't.
Ed Hamrick
> However, from the ASF description, I infer that the difficulty with
> Kodachrome is a physical problem with the way the scanners see the dyes
> in the emulsion. In short, they have difficulty differentiating defects
> from some color of dye. I would presume if they could fix it, they
> would have already. I therefore suspect that the same problems would
> present themselves with either software package.
The problem ASF has is that their ICE algorithm assumes that there's
little image detail in the image channel. VueScan's infrared cleaning
algorithm doesn't make this assumption, and works better with
Kodachrome.
When a dust spot is detected, VueScan and ICE both have to fill
in the hole with image data from around the dust spot. ASF's
code has done a better job of this in the past, but VueScan 7.6.11
has some significant improvements in this area. I hope to release
it today or tomorrow.
Regards,
Ed Hamrick
Ed Hamrick
> 2. Kodachromes absorb LESS in IR that Ektachromes. Go to www.kodak.com
> and search using kodachrome or ektachrome and data, open technical
> data file, find spectral curves and compare.
The problem isn't how much infrared gets absorbed by Kodachrome
vs. Ektachrome, the problem is that the film dyes in Kodachrome have
a lot more detail in the infrared channel than with Ektachrome.
This can be clearly seen by showing the infrared channel of
a Kodachrome scan and an Ektachrome scan. The Kodachrome
infrared scan looks like a flatter version of the image, but
the Ektachrome infrared scan looks completely flat with very
little image detail.
Regards,
Ed Hamrick
Erik Krause
you wrote...
> As in this example:
> http://www.stabbingpain.com/public/vs-ir.htm
>
> In short, is this to be expected?
Yes and no. It is said that Kodachrome can contain more metallic silver
than E6 films as a result of bad processing. Is there anyone who can
confirm this?
I never had something like what you showed with my Kodachromes scanned
with VueScan on Nikon LS40...
Mac McDougald
erik....@gmx.net says...
> Yes and no. It is said that Kodachrome can contain more metallic silver
> than E6 films as a result of bad processing. Is there anyone who can
> confirm this?
Silver content seems to be a factor.
According to Kodak KR25 processing guide (somewhere on Kodak's site, but
I don't have it handy), there is always some silver left in Koda, but if
process drifts out of control, there can be more.
E-6 (and C-41), even badly done, leaves NO silver, assuming the steps
that go to completion are accomplished.
Mac
Wayne Fulton
doogleRE...@nxs.net says...
>
>According to Kodak KR25 processing guide (somewhere on Kodak's site, but
>I don't have it handy), there is always some silver left in Koda, but if
>process drifts out of control, there can be more.
>
>E-6 (and C-41), even badly done, leaves NO silver, assuming the steps
>that go to completion are accomplished.
That is my understanding too. Conventional B&W film is silver based, and
conventional color film is dye based.
Kodachrome (dating back to 1935) is a cross, it having black and white
silver based layers, and during the processing step, the silver is removed
and replaced by added dye-couplers to create color at time of processing.
Variable processing results can leave some silver in the Kodachrome film,
mainly in the dark areas. Kodachrome is extremely different than all other
color film.
Silver blocks infrared, it is opaque metal, it blocks any light at all.
Dyes do not affect the infrared light, which is the principle of infrared
dust and scratch reduction when scanning color film. If it is visible in
infrared, then it aint dye, it must be dust or scratch. But in Kodachrome,
it may be remaining silver too.
Bottom line, if when scanning Kodachrome with infrared processing, and you
get strange results, turn off the infrared processing.
--
Wayne
http://www.scantips.com "A few scanning tips"
Mac McDougald
Fulton@ScanTips_N0spam.Com says...
<snippage, see thread>
> Bottom line, if when scanning Kodachrome with infrared processing, and you
> get strange results, turn off the infrared processing.
Patient: Doc, it hurts when I do this. Whattya think?
Doc: Don't DO that!
Mac
Bart van der Wolf
"Erik Krause" <erik....@gmx.net> wrote in message
news:MPG.18ac92569...@ID-18456.user.dfncis.de...
> Hi, Henri Gabriel
> you wrote...
>
> > As in this example:
> > http://www.stabbingpain.com/public/vs-ir.htm
> >
> > In short, is this to be expected?
>
> Yes and no. It is said that Kodachrome can contain more metallic silver
> than E6 films as a result of bad processing. Is there anyone who can
> confirm this?
The Kodak technical data sheet Z50_03 about the processing of Kodachrome
states that in the last steps before final washing:
QUOTE
Bleach
SNIP
Inadequate aeration, underreplenishment, low
temperature, and over-dilution of the bleach by conditioner
can cause silver retention, which causes all densities to
increase. The silver may be removed by bleaching and fixing
the film again, if necessary.
Fixer
The fixer converts all of the silver halide into soluble silver
compounds. Most of the silver compounds are removed in
the fixer and can be recovered.
Underreplenishment, or fixer dilution, causes silver halide
retention, increased blue density, or yellow D-min. The
silver halide may be removed by bleaching and fixing the
film again.
UNQUOTE
So the bleach step can cause silver retention which will not be removed by
the subsequent Fixer bath.
And under replenishment or fixer dilution can cause (light sensitive)
silver halide retention, which can also cause darkening of layers upon
continued exposure to light.
Anyway, it needs sub-standard processing for that to occur, and that of
course *never* happens, does it ;-).
Bart
Ed Hamrick
> ALL films contain ssilver salts (which are light sensitive), there is
> no difference between Ekta or Koda (or BW). Kodachromes have dyes
> added during processing, while Ektachromes have one part incorporated
> within the emulsion, and the other part comes from oxidised color
> developer. In each color process, all silver has to be oxidised
> (bleached) and removed (fixed).Maybe, large scale processing wcan
> exhaust the bleach so much (without proper replenishment) that some
> silver is left behind. It is the best explanation to the effect of
> poor scanability of Kodachromes.
It's a lot simpler than this. The dyes in Kodachrome absorb
some infrared light. The dyes in Ektachrome don't.
Regards,
Ed Hamrick
Jeff
isn't it? There's been some great input, especially from Ed and
Wayne.
In the 80's I shot a lot of Kodachrome, believing it was the best
archival film available. Now that seems to have been a bad decision.
My old Ektachromes and any print film are much better for scanning, in
that ICE saves so much time in the workflow, when it can be used.
Damn...
Ian
>
>Vuescan's version of ICE is not better than ASF's version. Just take
>a kodachrome, do the preview, then look at the IR in the preview.
>You'll see that it's all over the image like snow!
How does one "look at the IR in the preview" please?
I think I saw a check box somewhere below the infrared clean drop down
list on the filter tab, a few versions back. Seems to no longer be
there. I am missing something here?
FWIW IR cleaning using Vuescan on a Canon FS4000 scanning Kodachrome
or Fuji Provia certainly works sometimes. On occasions it does seem to
cause significant image quality loss. I haven't yet tied down the
circumstances that cause this variation.
Ian
Bart van der Wolf
"Ian" <da...@hemscott.net> wrote in message
news:k9da4v0cmt8cdoqhh...@4ax.com...
> On 5 Feb 2003 07:57:51 -0800, jeff...@mac.com (Jeff) wrote:
>
>
> >
> >Vuescan's version of ICE is not better than ASF's version. Just take
> >a kodachrome, do the preview, then look at the IR in the preview.
> >You'll see that it's all over the image like snow!
>
> How does one "look at the IR in the preview" please?
It's on the Color tab, the View color option allows the display of the IR
channel only.
Bart
Ian
Bart,
Arrgghhhh!
Many Thanks
Ian