emulsion side down and histograms

Hello,
I have two questions.

When scanning 35mm or 4x5s does the emulsion side go down? Is there a
rule for this? I thought it went down but my scans are mirrored and I
get different results when emulsion is up or down.

Is it better to adjust the levels (histogram) with the scanning
software or in Photoshop? I don't want to lose information when
scanning. I've read scantips.com, searched this group and googled. I
have alot of slides of artwork to scan. I don't want the fastest way,
I'd like to do it the best way.

I'm using Silverfast SE (came with the scanner) and an Epson 4870. I
don't know if it's relevant but I'm on a Mac with system 9.2.2

I've become a bit scrambled over this and any help will be so
appreciated.

Thanks, Linda

--
remove invalid to reply

Scan so the image comes out with correct orientation (however whichever way
yields best results for you is all that counts).
There are two schools of thought about image tuning: adjust extensively
prescan, adjust minimally prescan.
Again whatever works for you works best for you. My personal preference is
to make minimal adjustments prescan that yield uncompromised/unclipped
images and adjust later in Photoshop.
Severely underexposed or overexposed images may require extensive prescan
adjustment to get any kind of usable image.
You have to experiment and learn what you are doing.
It is more important to understand what the adjustments actually are doing
to the image data then to worry about whether or not to make adjustments pre
or post scan.

When scanning 35mm or 4x5s does the emulsion side go down? Is there a
rule for this? I thought it went down but my scans are mirrored and I
get different results when emulsion is up or down.

You don't explain what you find "different?" Which produces better results
for you? That is the best answer. If you want to know what Epson
recommends, look at the letter graphic/decal on the holder. That shows how
the lettering on your film should read when you look at the film after it is
placed in the holder.

Doug

--
Doug's "MF Film Holder" for batch scanning "strips" of 120/220 medium format
film:
http://home.earthlink.net/~dougfishe...mainintro.html

Emulsion Down, and 'flip' the image either in the scanning program or in
PhotoShop.

Just ask yourself ... just exactly WHY should I scan *through* the film
base?




"Linda" wrote in message
. com...
Hello,
I have two questions.

When scanning 35mm or 4x5s does the emulsion side go down? Is there a
rule for this? I thought it went down but my scans are mirrored and I
get different results when emulsion is up or down.

Is it better to adjust the levels (histogram) with the scanning
software or in Photoshop? I don't want to lose information when
scanning. I've read scantips.com, searched this group and googled. I
have alot of slides of artwork to scan. I don't want the fastest way,
I'd like to do it the best way.

I'm using Silverfast SE (came with the scanner) and an Epson 4870. I
don't know if it's relevant but I'm on a Mac with system 9.2.2

I've become a bit scrambled over this and any help will be so
appreciated.

Thanks, Linda

--
remove invalid to reply

"RSD99" wrote in message
news:lc%ue.902$Uc2.403@trnddc03...
Emulsion Down, and 'flip' the image either in the scanning program or in
PhotoShop.

Just ask yourself ... just exactly WHY should I scan *through* the film
base?



Maybe because the light travels through the film base to produce the image
on the sensor. Either way you turn the film, the light has to travel through
the film to get to the sensor.

That is why it is called a transparency, light passes through the film.

You turn the film the way that when scanned produces a right side up or
correct left to right image. Sometimes with some scanners the image maybe
correct left to right but upside down.

My Canon CanoScan 8400F scans 120 negatives shot with a twin lens reflex
camera are upside down when scanned with the correct left to right
orientation. A simple matter to turn all the images in the image editor at
the same time. (The scanner driver can also rotate the image, one at a
time).

And yes, you can flip or rotate the image in a photo editor, no matter which
way you scanned it.

--
CSM1
http://www.carlmcmillan.com
--


"Linda" wrote in message
. com...
Hello,
I have two questions.

When scanning 35mm or 4x5s does the emulsion side go down? Is there a
rule for this? I thought it went down but my scans are mirrored and I
get different results when emulsion is up or down.

Is it better to adjust the levels (histogram) with the scanning
software or in Photoshop? I don't want to lose information when
scanning. I've read scantips.com, searched this group and googled. I
have alot of slides of artwork to scan. I don't want the fastest way,
I'd like to do it the best way.

I'm using Silverfast SE (came with the scanner) and an Epson 4870. I
don't know if it's relevant but I'm on a Mac with system 9.2.2

I've become a bit scrambled over this and any help will be so
appreciated.

Thanks, Linda

--
remove invalid to reply

But one way ... with the emulsion side of the film *down* ... the *image*
does *not* have to travel through the dirt, distortion and contamination(s)
of the film base. The film base is, was, and always will be manufactured to
simply be a support for the emulsion. The film base was *never* designed to
be part of the optical path, and is not manufactured to the parameters that
would be required for that usage. .

Don't you think that just might be the reason why *all* optical enlargers
and projection systems place the emulsion side of the image towards the
final projected image?






"CSM1" wrote in message
...

Maybe because the light travels through the film base to produce the
image
on the sensor. Either way you turn the film, the light has to travel
through
the film to get to the sensor.

That is why it is called a transparency, light passes through the film.

You turn the film the way that when scanned produces a right side up or
correct left to right image. Sometimes with some scanners the image maybe
correct left to right but upside down.

My Canon CanoScan 8400F scans 120 negatives shot with a twin lens reflex
camera are upside down when scanned with the correct left to right
orientation. A simple matter to turn all the images in the image editor
at
the same time. (The scanner driver can also rotate the image, one at a
time).

And yes, you can flip or rotate the image in a photo editor, no matter
which
way you scanned it.

--
CSM1
http://www.carlmcmillan.com
--


"Linda" wrote in message
. com...
Hello,
I have two questions.

When scanning 35mm or 4x5s does the emulsion side go down? Is there a
rule for this? I thought it went down but my scans are mirrored and I
get different results when emulsion is up or down.

Is it better to adjust the levels (histogram) with the scanning
software or in Photoshop? I don't want to lose information when
scanning. I've read scantips.com, searched this group and googled. I
have alot of slides of artwork to scan. I don't want the fastest way,
I'd like to do it the best way.

I'm using Silverfast SE (came with the scanner) and an Epson 4870. I
don't know if it's relevant but I'm on a Mac with system 9.2.2

I've become a bit scrambled over this and any help will be so
appreciated.

Thanks, Linda

--
remove invalid to reply

In article pHhve.1096$4M1.772@trnddc07, says...


But one way ... with the emulsion side of the film *down* ... the *image*
does *not* have to travel through the dirt, distortion and contamination(s)
of the film base. The film base is, was, and always will be manufactured to
simply be a support for the emulsion. The film base was *never* designed to
be part of the optical path, and is not manufactured to the parameters that
would be required for that usage. .

Don't you think that just might be the reason why *all* optical enlargers
and projection systems place the emulsion side of the image towards the
final projected image?


Undoubtedly only to prevent it coming out reversed left to right.

However which in turn is because the camera does it too, to which your point
is applicable. Early roll film (620/120) even had an opaque paper backing
to protect it, which would have otherwise made it very difficult indeed to
turn it over. All these systems place emulsion towards lens, and it
comes out right, because all are front surface projections.

The flatbed CCD chip surface is also a projection surface, but the chip
views that projected image from the inside, or from the back side of the
projection surface, which is a reversal. Dedicated film scanners could
choose to always flip the image, and then expect the film emulsion towards
the lens. Or not, it really doesnt matter who does it.

But flatbeds primarily expect to scan prints or documents, which are not
reversed like film is, so film emulsion must go up (away from lens) to
prevent retaining the reversal. Film is initially reversed due to
orientation in camera, and (excepting front surface projection, which is
normal for enlargers and projectors) is properly viewed from the back side
(preventing left to right reversal).

One could choose to scan it backwards and flip it later, and there is no
harm in it, but the thickness of the film base is a trivial concern as
compared to the flatbed glass bed.

--
Wayne
http://www.scantips.com "A few scanning tips"

"RSD99" wrote in message
newsHhve.1096$4M1.772@trnddc07...
But one way ... with the emulsion side of the film *down* ... the *image*
does *not* have to travel through the dirt, distortion and
contamination(s)
of the film base. The film base is, was, and always will be manufactured
to
simply be a support for the emulsion. The film base was *never* designed
to
be part of the optical path, and is not manufactured to the parameters
that
would be required for that usage. .


The film base is a part of the optical path. The orange base color of Color
Negative film is an very important part of the film/print process. Slides
which have a clear film base still used the film base as a part of the
optical path, especially if projecting in a Slide projector.

The image is made from the light and the density of the emulsion of the
film. The film base can not be removed from the equation.

You can not separate the image from the film base.


Don't you think that just might be the reason why *all* optical enlargers
and projection systems place the emulsion side of the image towards the
final projected image?

The emulsion side is toward the paper because that is the correct
orientation of the image as photographed by the camera.

A optical enlarger such as used in a darkroom to make photographic prints on
photographic paper (The standard Film camera, develop the film, print the
picture kind) transmits the light source through the film through a lens
onto the paper, thereby making an image on the paper which is then developed
in chemicals. The film is between the light source and the lens of the
enlarger. The same as in a scanner, the film is between the light and the
sensor.

Any dirt, dust or crap on either surface of the film will make a white spot
on the print.

That is why film must be clean to make spot free prints or images of any
kind, digital or optical. It is simple physics, when light passes through an
object, it passes through both surfaces.

--
CSM1
http://www.carlmcmillan.com
--

"CSM1" posted:
"...
It is simple physics, when light passes through an
object, it passes through both surfaces.
...."

That is true ... but there is a significant difference between
"transmitting light" through a semi-transparent (and also distorting)
substrate and "transmitting an image" through the same substrate.

Would you, for instance, prefer to take a picture through a (dirty) window
or mirror, or would you move the camera slightly to view the same scene
directly ... without "looking through the window?"

Correspondingly, the *image* on a piece of film does not need to be "read"
through the additional distortions of the film base simply because that
gives the proper "orientation." That's what the 'Invert' function of the
scanner software (and PhotoShop) are for.

As I posted, the film base is designed and manufactured simply to hold the
emulsion. It is *not* designed to be part of an optical (or image)
"chain," and the material used is not designed to, nor does it have, the
suitable optical properties.

Otherwise we would all be still be taking our photographs on glass plates
.... and *optical* grade glass plates at that!

I stand by my previous advice that film is best scanned with the emulsion
side towards the sensor. Historically (traditionally) for several reasons
this is the method used. Only *one* of those reasons is that it provides
the proper image orientation with the optical system(s) used.

You, of course, are free to scan your images through the distortion(s) that
might be caused by the film base.









"CSM1" wrote in message
m...
"RSD99" wrote in message
newsHhve.1096$4M1.772@trnddc07...
But one way ... with the emulsion side of the film *down* ... the
*image*
does *not* have to travel through the dirt, distortion and
contamination(s)
of the film base. The film base is, was, and always will be
manufactured
to
simply be a support for the emulsion. The film base was *never*
designed
to
be part of the optical path, and is not manufactured to the parameters
that
would be required for that usage. .


The film base is a part of the optical path. The orange base color of
Color
Negative film is an very important part of the film/print process. Slides
which have a clear film base still used the film base as a part of the
optical path, especially if projecting in a Slide projector.

The image is made from the light and the density of the emulsion of the
film. The film base can not be removed from the equation.

You can not separate the image from the film base.


Don't you think that just might be the reason why *all* optical
enlargers
and projection systems place the emulsion side of the image towards the
final projected image?

The emulsion side is toward the paper because that is the correct
orientation of the image as photographed by the camera.

A optical enlarger such as used in a darkroom to make photographic prints
on
photographic paper (The standard Film camera, develop the film, print the
picture kind) transmits the light source through the film through a lens
onto the paper, thereby making an image on the paper which is then
developed
in chemicals. The film is between the light source and the lens of the
enlarger. The same as in a scanner, the film is between the light and the
sensor.

Any dirt, dust or crap on either surface of the film will make a white
spot
on the print.

That is why film must be clean to make spot free prints or images of any
kind, digital or optical. It is simple physics, when light passes through
an
object, it passes through both surfaces.

--
CSM1
http://www.carlmcmillan.com
--

In article , CSM1
writes
"RSD99" wrote in message
news:lc%ue.902$Uc2.403@trnddc03...
Emulsion Down, and 'flip' the image either in the scanning program or in
PhotoShop.

Just ask yourself ... just exactly WHY should I scan *through* the film
base?



Maybe because the light travels through the film base to produce the image
on the sensor.

It certainly does, but after the light has been spatially modulated by
the image it only passes through the film base *if* the film is oriented
the wrong way. Consequently, the optical loss on the *image* only
occurs if the film is oriented with the emulsion on the side of the
light source - which *is* the wrong way.

Put it another way. The film base is not perfect - it scatters and
distorts the light to a certain degree. If the base is on the
illumination side then that scattering and distortion of the light only
serves as a diffuser. Even if the film base scattered significantly,
all that would happen would be that the light reaching the emulsion (and
hence the image) would be more diffuse. The image would still be
perfectly formed on the CCD by the scanner's primary lens. Indeed,
certain scanners have specific diffusers designed into them because
there are advantages of a diffuse source. Mount the film the wrong way
round and that built in mild diffusion on the film base affects the
*image* as well as the illumination. Mount it the correct way and only
the image is not affected.

Either way you turn the film, the light has to travel through
the film to get to the sensor.

In an enlarger, light has to travel through the condenser lens or the
diffuser to get to the sensor too - and the same thing happens in
scanners. In neither enlarger nor scanner does the condenser or
diffuser have the same image forming capabilities as the primary lens -
they don't need to because the light passes through them before it picks
up the image. The same is true of the film base - if it is oriented
correctly.

Conduct a simple experiment. Make a synthetically bad film base by
taping a sheet of tracing paper to one side of the slide. Hold it up to
a light source and look through it in each orientation - with the
tracing paper on the illumination side and then again with the tracing
paper on the sensor side (ie. towards your eye). In which orientation
do you see the cleanest sharpest image? Well, to a much lesser degree,
that same light scattering of the tracing paper occurs in the film base
itself.

As a result of conducting that experiment, come back and tell us which
side the non-optical graded film base should be on!

The image losses introduced by scanning the film in the wrong
orientation are minimal and in almost all cases (unless you happen to
get a rogue batch of film) there are other more significant loss
mechanisms, but they are never zero. Since they are unspecified and
variable they are best avoided by adopting the correct orientation as
the default. Only flip the film if there is no alternative.
--
Kennedy
Yes, Socrates himself is particularly missed;
A lovely little thinker, but a bugger when he's ****ed.
Python Philosophers (replace 'nospam' with 'kennedym' when replying)