Digital BW, The Print

Dear all:

I recently gave an enormous jump. After asking for your wise opinion on sca=
nners, I 
decided to buy a Nikon 5000. I could not find a reliable 8000 and the 9000 =
is too 
expensive.

I am, thus, back to film. DSLR is good, but, to my mind, unsatisfactory whe=
n it comes to 
resolve big tonal gaps. And, ça va de soi, when it comes to print the resul=
t. I will use it 
sometimes. In fact, I used it yesterday to make portraits of one of our vis=
iting novelists, 
but I also took film cameras, both with Portra 160NC. Although I wanted the=
 portraits to 
be in B&W, DSLR made me change my visualization techniques: with the DSLR y=
ou have to 
shoot color, and you only think in BW when you are in front of the computer=
.

Now that I am back to film, I am wonderig whether I should keep this techni=
que or go back 
to thinking in BW from the very beginning. When I make BW out of color film=
 (both 
negatives and slides), I find the result a bit flat, lacking of tonal range=
. Maybe I am not 
using the right technique to do it (either Photoshop Grayscale or TheImagin=
gFactory 
Convert to BW pro). I have also noticed that scanning BW negatives is not n=
ecessarily an 
easy task.

Is there a good idea about what is the best film (BW, BW for C41, color to =
convert...) to get 
a good, full tonal range picture in this conditions?

Thank you very much
J

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Jesus RV" 
<jrv@s...> wrote:

> Is there a good idea about what is the best film (BW, BW for C41, 
color to =
> convert...) to get 
> a good, full tonal range picture in this conditions?
> 
I find that FP4+ in ID11 from pre XTOL days are easy scans on a Nikon 
Coolscan V, so much so that I'm going back to this film. Will test 
with both ID11 and XTOL in the coming weeks.

Cheers,
Andre

Hello again.  With the Nikon scanner I have good wide-range results from
Kodak Portra 400 b&w, if you have a pro C-41 lab nearby.  So far as I can
tell it is a true 400 speed.  I have never had good results doing a b&w
conversion from color neg film, though I have had good results converting
Canon DSLR raw files to b&w  (the Capture One raw converter allows you to
see them in grayscale).  I prefer it to the raw program in PS CS, though it
is a fine point.  One problem: the Portra negs are not archival.  

Regards,

  --Ken Carney
    www.kencarney.com  

> -----Original Message-----
> From: Jesus RV [mailto:jrv@...] 
> Sent: Saturday, April 10, 2004 8:23 PM
> To: DigitalBlackandWhiteThePrint@yahoogroups.com
> Subject: [Digital BW] On film
> 
> Dear all:
> 
> I recently gave an enormous jump. After asking for your wise 
> opinion on sca=
> 
> nners, I
> decided to buy a Nikon 5000. I could not find a reliable 8000 
> and the 9000 =
> 
> is too
> expensive.
> 
> I am, thus, back to film. DSLR is good, but, to my mind, 
> unsatisfactory whe=
> 
> n it comes to
> resolve big tonal gaps. And, ça va de soi, when it comes to 
> print the resul=
> 
> t. I will use it
> sometimes. In fact, I used it yesterday to make portraits of 
> one of our vis=
> 
> iting novelists,
> but I also took film cameras, both with Portra 160NC. 
> Although I wanted the=
> 
>  portraits to
> be in B&W, DSLR made me change my visualization techniques: 
> with the DSLR y=
> 
> ou have to
> shoot color, and you only think in BW when you are in front 
> of the computer=
> 
> .
> 
> Now that I am back to film, I am wonderig whether I should 
> keep this techni=
> 
> que or go back
> to thinking in BW from the very beginning. When I make BW out 
> of color film=
> 
>  (both
> negatives and slides), I find the result a bit flat, lacking 
> of tonal range=
> 
> . Maybe I am not
> using the right technique to do it (either Photoshop 
> Grayscale or TheImagin=
> 
> gFactory
> Convert to BW pro). I have also noticed that scanning BW 
> negatives is not n=
> 
> ecessarily an
> easy task.
> 
> Is there a good idea about what is the best film (BW, BW for 
> C41, color to =
> 
> convert...) to get
> a good, full tonal range picture in this conditions?
> 
> Thank you very much
> J
> 
> 
> 
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Jesus RV writes:

> When I make BW out of color film (both negatives and slides), I find
> the result a bit flat, lacking of tonal range.

This is a natural result of the way color gets converted to black and
white.  True black and white films have a different spectral response
and can produce more contrast in a given scene than color will produce
when grayscaled.  For example, the well-known relative insensitivity of
Kodak Tri-X to red light produces sharper contrast in black and white
than you would get from a color conversion (while red is easy to
distinguish from other colors in color images, from a luminance
standpoint it's very close to many other colors, so if you convert it
as-is to black and white, a lack of contrast is often the result).

> Maybe I am not using the right technique to do it (either Photoshop
> Grayscale or TheImagingFactory Convert to BW pro).

There are many ways of converting color to B&W that can improve the
results.  However, you can never obtain the full flexibility of shooting
in black and white to begin with, since so much information is already
gone once you've captured an image in color.

If you want the best black and white, you must shoot in black and white.
You can shoot digitally or on film, but if you shoot digitally, you need
a B&W digital camera, and currently no such digital cameras exist.  So
essentially you have to shoot film for straight black and white.

> I have also noticed that scanning BW negatives is not necessarily an
> easy task.

Black and white films can be very dense (a big difference between the
clear film and the darkest parts of the negative), and only good
scanners can penetrate this.  Nikon scanners are very good, though.

> Is there a good idea about what is the best film (BW, BW for C41,
> color to convert...) to get a good, full tonal range picture in this
> conditions?

Film choices are often a matter of pure personal preference.  I like
Tri-X, except for the grain.  Technical Pan is superb, but it is so slow
that it can't be used in many situations.  Kodak Portra 400BW is very
good for shooting contrasty scenes, especially night scenes, and the
grain is so extraordinarily fine and the resolution so high that it is
almost a poor man's Tech Pan--plus it is quite fast, at ISO 400.

Techpan is excellent, but when developed in Photographer's Formulary 
TD-3 you can rate at 80-100 asa so it isn't *that* slow.  I don't 
find T400CN or Portra 400BW to be anything near TP... Tmax 100 
possibly, but nowhere near as sharp.

I think you need to have a better understanding on how to convert to 
b&w before you can judge a color film for this task though.  You can 
mimic a film's response to color very well if you tweak the Channel 
Mixer and color curves while converting to b&w instead of just using 
a "big button" approach.

I don't using color film for b&w because I prefer ISO 400 and I don't 
like the resulting grain from color films of this speed.  T400CN 
works very well for scanning (but you still have to work with curves 
to get it to appear like a traditional silver emulsion film).

Read some more tutorials on converting color to b&w.

mark

PS  My workflow: layers: Curve Adjust and Channel Mixer, work both 
with preview until I am happy.  RGB color curves give complete 
variable control over each channel and the channel mixer linearly 
blends them down to b&w.  Takes about a minute and *you* control the 
entire process.

...
> > Is there a good idea about what is the best film (BW, BW for C41,
> > color to convert...) to get a good, full tonal range picture in 
this
> > conditions?
> 
> Film choices are often a matter of pure personal preference.  I like
> Tri-X, except for the grain.  Technical Pan is superb, but it is so 
slow
> that it can't be used in many situations.  Kodak Portra 400BW is 
very
> good for shooting contrasty scenes, especially night scenes, and the
> grain is so extraordinarily fine and the resolution so high that it 
is
> almost a poor man's Tech Pan--plus it is quite fast, at ISO 400.

It's true 400 if you are actually metering exclusively for the 
shadows, but with a typical in-camera meter I find that I am much 
better rating it at 320... a small Oly rangefinder that I 
occasionally shoot only has a setting for 250 and that probably is 
even better.

mark

...
> Kodak Portra 400 b&w, if you have a pro C-41 lab nearby.  So far as 
I can
> tell it is a true 400 speed.  
...

Mark Hahn writes:

> I think you need to have a better understanding on how to convert to
> b&w before you can judge a color film for this task though.

My understanding is excellent.  I've already explained why color film
can never exactly duplicate the results obtained from true black and
white film, frequently and at length.

> You can mimic a film's response to color very well if you tweak the
> Channel Mixer and color curves while converting to b&w instead of just
> using a "big button" approach.

Why mimic if you can just shoot black and white to begin with?

> Read some more tutorials on converting color to b&w.

Instead of writing them?

On Sunday, April 11, 2004, at 03:53 AM, Anthony G. Atkielski wrote:

>
> There are many ways of converting color to B&W that can improve the
> results.  However, you can never obtain the full flexibility of 
> shooting
> in black and white to begin with, since so much information is already
> gone once you've captured an image in color.

You actually have MORE flexibility if you shoot in color and convert to 
B&W not less. If you shoot in B&W with a yellow, green or red filter in 
front of your lens you are forever stuck with those tonal renditions. 
If you shoot in color and use the channel mixer to convert, you have 
more flexibility because you can choose the tonal rendition and color 
relationships in the digital darkroom rather than while shooting.

Furthermore, in one sense you do have less "information / resolution" 
when you shoot with a digital camera in color but on another hand you 
have more "information" because you have all the original color 
information and at a low ISO you get an image with no grain or scanner 
induced grain aliasing.

Shooting with a DSLR is not the same as shooing B&W film but they 
really both have there own  advantages.


-Jeff

Jeff Magidson writes:

> You actually have MORE flexibility if you shoot in color and convert to
> B&W not less.

No, you don't.  Why are photographers so fond of superstition and myth?

> If you shoot in B&W with a yellow, green or red filter in
> front of your lens you are forever stuck with those tonal renditions.

But the whole point is that those renditions are exactly what you want.
And you can't get them by converting color.

> If you shoot in color and use the channel mixer to convert, you have
> more flexibility because you can choose the tonal rendition and color 
> relationships in the digital darkroom rather than while shooting.

Most of the renditions are impossible in color conversions, because they
require information missing from a color image.

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Anthony G. 
Atkielski" <anthony@a...> wrote: 
> Most of the renditions are impossible in color conversions, because they require information missing from a color image.

I'm curious as to what information is missing from the color image 
that would be in the black and white. I too find that I often can't 
match the look of black and white film with a color conversion, but 
have always assumed that some amount of messing around would do it. 

Mark

If you use Photoshop, correct the image the best you can in RGB and then
convert the image to LAB color by going to Image>Mode>Lab color.. LAB color
separates the image into three channels. Lightness (isolates all the detail)
and isolates the color in channels A & B ... (Hence L-A-B Color). Once you
have converted to Lab color, go to channels and click on the lightness
channel and lo, you get a BW image with all the detail and none of the
color. Then make your corrections with levels and curves in that order.
Avoid the brightness and contrast controls ... they destroy information ...
levels and curves does not.

Once you are satisfied with the image, sharpen it if you care to and save it
as (image number or name-BW. The you can reopen your existing image and
convert back to RGB and it is as it was before you started working on it. I
have also used the Fred Miranda Black and White Workflow Plug-in with some
success for converting RGB to BW. NEVER convert to BW by merely converting
the mode to grayscale. You let the computer interpolate what it thinks the
BW shades of gray should be and I trust my eyes more than I do the
processor. One further hint. As of late, I have been converting my color
images to LAB and selecting the lightness channel for sharpening and am
getting better overall appearance. After sharpening, I convert back to RGB.

Hope this helps,
Joe

  -----Original Message-----
  From: cirkutguy [mailto:cirkut@...]
  Sent: Sunday, April 11, 2004 3:06 PM
  To: DigitalBlackandWhiteThePrint@yahoogroups.com
  Subject: Re: [Digital BW] On film


  --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Anthony G.
  Atkielski" <anthony@a...> wrote:
  > Most of the renditions are impossible in color conversions, because they
require information missing from a color image.

  I'm curious as to what information is missing from the color image
  that would be in the black and white. I too find that I often can't
  match the look of black and white film with a color conversion, but
  have always assumed that some amount of messing around would do it.

  Mark





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

> From: cirkutguy [mailto:cirkut@...]
>
> I'm curious as to what information is missing from the color image
> that would be in the black and white. I too find that I often can't
> match the look of black and white film with a color conversion, but
> have always assumed that some amount of messing around would do it.

A B&W image obviously doesn't contain more information than an RGB image,
but the color light coming in the front of the lens certainly contains a lot
more information than what's finally represented on color film in RGB. If
you have a good assortment of filters, you can get spectral responses that
you can't get after the image has been reduced to RGB.

However, there are also dramatic things that can be done on RGB images, such
as subtracting the blue channel in order to make skies even darker, which
you can't possibly do once you've reduced the image to B&W. So in my view,
you get a wider range of effects from shooting color and converting to B&W
in PS, compared to shooting B&W with filters in front of the lens. Also, the
convenience and opportunity for experimentation are self-evidently better
with post-processing. Finally, there's no law that says you can't put
filters over the lens, AND shoot color and convert to B&W afterwards, if
there's some magic spectral response that you can't get without the filter.

--

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@...

The question is a fairly simple one and relates to the physics of the 
situtation. It is - "is all the energy of the visible spectrum reflected 
off a scene contained in three discrete colors (Red, Green and Blue)?"  
If the answer is yes then one can reproduce any image with three 
discrete channels - red, green and blue. If there is energy that is 
attuniated but in the visible spectrum by only capturing three discrete 
frequency bands, then there are images that can not be produced.

Another way to put it is can one generate a camalflodge where the 
appreance is significantly attenuated in a scene captured using three 
discrete frequency channels but is visible to an energy intensity filter?

The answer to these questions will settle the technical argument. 
However, the argument aesthetics will probaobably go on forever.

Truman

Paul D. DeRocco wrote:

> > From: cirkutguy [mailto:cirkut@...]
> >
> > I'm curious as to what information is missing from the color image
> > that would be in the black and white. I too find that I often can't
> > match the look of black and white film with a color conversion, but
> > have always assumed that some amount of messing around would do it.
>
> A B&W image obviously doesn't contain more information than an RGB image,
> but the color light coming in the front of the lens certainly contains 
> a lot
> more information than what's finally represented on color film in RGB. If
> you have a good assortment of filters, you can get spectral responses that
> you can't get after the image has been reduced to RGB.
>
> However, there are also dramatic things that can be done on RGB 
> images, such
> as subtracting the blue channel in order to make skies even darker, which
> you can't possibly do once you've reduced the image to B&W. So in my view,
> you get a wider range of effects from shooting color and converting to B&W
> in PS, compared to shooting B&W with filters in front of the lens. 
> Also, the
> convenience and opportunity for experimentation are self-evidently better
> with post-processing. Finally, there's no law that says you can't put
> filters over the lens, AND shoot color and convert to B&W afterwards, if
> there's some magic spectral response that you can't get without the 
> filter.
>
> --
>
> Ciao,               Paul D. DeRocco
> Paul                mailto:pderocco@...
>

-- 

We imitate our masters only because we are not yet masters ourselves, 
and only

because in doing so we learn the truth about what cannot be imitated.

 



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

cirkutguy writes:

> I'm curious as to what information is missing from the color image
> that would be in the black and white.

Well, it's a long story ...

The light in a real-world image consists of a blend of an (essentially)
infinite number of frequencies at an infinite number of amplitudes, for
every point (pixel) in the image.  No capture device is capable of
recording an infinite number of amplitudes for an infinite number of
frequencies for each pixel, so a great deal of information is discarded
when image capture occurs.  In a color image, all of the original
information is reduced to three numbers, based on a fixed, one-way
conversion function.  In a black and white image,
all of the original information is reduced to one number, using a
different conversion function.

It's mathematically impossible to reconstruct the original scene
information from either B&W or color image captures.  Most of the
original information is gone, and cannot be recovered.  Since both types
of capture are functions of the full range of original image
information, there is no transformation that can be performed on a given
set of image data that will convert it into the image data that would
result from a different type of capture.

For example, it's intuitively obvious that a color image cannot be
reconstructed from a black and white image file. However, it is also
true that a black and white image cannot be reconstructed from a color
image file. It's possible to produce black and white images the capture
of which would be a subset of the function that produced the color
images (i.e., in which all information necessary has been preserved),
but not anything else.

In consequence, there exists an infinite number of black and white
images that can only be produced by capturing an original scene directly
in black and white with an appropriate monochrome capture method. No
manipulation of a color scene can produce these black and white images.

In summary: if you want to shoot black and white, you must _capture_ the
original image in black and white.  Converting color always gives an
inferior result.

> I too find that I often can't match the look of black and white
> film with a color conversion, but have always assumed that some
> amount of messing around would do it.

You can come close to the look of some black and white films, but you
cannot duplicate the look.  If you really must have exactly the look of
a particular B&W film, you must shoot that film directly.

This is even more true if you are using any kind of filters when taking
the shots.

Anthony G. Atkielski said the following on 4/11/2004 5:26 PM:

> In summary: if you want to shoot black and white, you must _capture_ the
> original image in black and white.  Converting color always gives an
> inferior result.

You can't capture the original image in B&W. It is in color. Mapping it 
to B&W involves a series of implicit decisions about what brightnesss to 
assign assign to a specific colored point.
For film, the decisions are made by the folk who designed its spectral 
response, modified by the photographer who may use a filter.
For a digital capture, the decision about the relative balance could be 
delegated to the camera manufacturer by switching to a B&W mode, or 
control could be maintained by the photographer by by playing with the 
RGB balance in channel mixer. This may or may not be inferior to the 
manufacturer's setting.

>>I too find that I often can't match the look of black and white
>>film with a color conversion, but have always assumed that some
>>amount of messing around would do it.
> 
> 
> You can come close to the look of some black and white films, but you
> cannot duplicate the look.  If you really must have exactly the look of
> a particular B&W film, you must shoot that film directly.
> 
> This is even more true if you are using any kind of filters when taking
> the shots.


...
I completely agree.
-- 
Clive
http://clive.moss.net

Clive Moss writes:

> You can't capture the original image in B&W. It is in color.

The image is in color.  You can use a monochrome sensor or B&W film to
capture it in B&W.

> Mapping it to B&W involves a series of implicit decisions
> about what brightnesss to assign assign to a specific colored
> point.

Yup, and they are a function of the _total_ spectrum included in the
original scene.  That spectrum is available at the time of capture, but
it is impossible to reconstruct from any other previous capture.  This
is why you must capture in black and white to begin with.

> For a digital capture, the decision about the relative balance could be
> delegated to the camera manufacturer by switching to a B&W mode, or 
> control could be maintained by the photographer by by playing with the
> RGB balance in channel mixer.

No, this isn't possible.  In the case of a digital capture, the capture
device is fixed in its capabilities.  The total spectrum of the original
scene is converted to three color values in a fixed and finite way.
Thereafter, it _cannot_ be transformed into the equivalent of an
entirely different capture.

Using a black and white mode doesn't help, because the sensor itself
still is covered with a matrix color filter.  You must remove the color
filter in order to get true black and white, in which case the
characteristics of the capture will be determined by the spectral
sensitivity of the chip (quite wide and flat for CCDs, as long as there
is an infrared filter in place).

Black and white film is an power sensor. It simply measurses the power 
(it counts photons) at a location on the film. A CCD is a power sensor. 
It only counts the photons at a location. The only reason it can 
measures red or green is there is a filter in front of it that filters 
one all but one single frequency photons. Light is not only made up of 
three frequencies - it is a continuum with the visible spectrum being 
from a little above IR to a little below UV.

So the question is how well can one predict the actual energy on a pixel 
per pixel basis using only pixels from there discrete frequencies.

It is a very easy experiment to run and it has been run many times. Take 
a CDD without any color filter and measure an image. Measure it with 
three sensors one with red, green and blue filters. Now take the entire 
scene and minimize the error of the between a weighted combination of 
the R, G and B sensors and the output of the CCD without any color 
filter. There is a set of weights that minimize the error, but the error 
will not be zero. That is the information lost.

Now does that make a difference to the observer - to some it will to 
some it won't.

Truman

Clive Moss wrote:

> Anthony G. Atkielski said the following on 4/11/2004 5:26 PM:
>
> > In summary: if you want to shoot black and white, you must _capture_ the
> > original image in black and white.  Converting color always gives an
> > inferior result.
>
> You can't capture the original image in B&W. It is in color. Mapping it
> to B&W involves a series of implicit decisions about what brightnesss to
> assign assign to a specific colored point.
> For film, the decisions are made by the folk who designed its spectral
> response, modified by the photographer who may use a filter.
> For a digital capture, the decision about the relative balance could be
> delegated to the camera manufacturer by switching to a B&W mode, or
> control could be maintained by the photographer by by playing with the
> RGB balance in channel mixer. This may or may not be inferior to the
> manufacturer's setting.
>

-- 

We imitate our masters only because we are not yet masters ourselves, 
and only

because in doing so we learn the truth about what cannot be imitated.

 



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

Anthony G. Atkielski wrote:

>Using a black and white mode doesn't help, because the sensor itself
>still is covered with a matrix color filter.  You must remove the color
>filter in order to get true black and white, in which case the
>characteristics of the capture will be determined by the spectral
>sensitivity of the chip (quite wide and flat for CCDs, as long as there
>is an infrared filter in place).
>
>
>  
>
Wide in the sense that it is "spectrally wide," yes.  But shooting B&W 
digitally is much like converting a color slide to B&W...

The exposure latitude, or number of exposure zones, representable is 
VERY narrow, when compared to B&W film..

 
Keith Krebs

"Just some guy," caretaker of the Multiverse's largest EPSON printer 
User Community (highly recommended by Vogon Poets and MegaDodo 
Publications), at:
http://groups.yahoo.com/group/EPSON_Printers/
and  the Multiverse's largest Canon printer User  Community at:
http://groups.yahoo.com/group/Canon-printers
"For the rest of you out there, the secret is to bang the rocks together 
guys"

On Sunday, April 11, 2004, at 06:26 PM, Anthony G. Atkielski wrote:
>
>
> In summary: if you want to shoot black and white, you must _capture_ 
> the
> original image in black and white.  Converting color always gives an
> inferior result.
>
>

Anthony... I'm trying to grasp your premiss.

On practical terms how would the resulting images be Inferior? What 
would they be lacking? Would anyone but the photographer say " wow.. 
these are inferior photographs and must have been made with a digital 
camera or on color film and converted to B&W rather than shot on B&W 
film" ?

-Jeff

PS: That experiment has been performed many times - always with the same 
results.

Truman Prevatt wrote:

>
> It is a very easy experiment to run and it has been run many times. Take
> a CDD without any color filter and measure an image. Measure it with
> three sensors one with red, green and blue filters. Now take the entire
> scene and minimize the error of the between a weighted combination of
> the R, G and B sensors and the output of the CCD without any color
> filter. There is a set of weights that minimize the error, but the error
> will not be zero. That is the information lost.
>
> Now does that make a difference to the observer - to some it will to
> some it won't.
>
> Truman


-- 

We imitate our masters only because we are not yet masters ourselves, 
and only

because in doing so we learn the truth about what cannot be imitated.

 



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

has this not been argued time and time again?  Please
use personal email instead of the list to argue.

don


--- Truman Prevatt <tprevatt@...> wrote:
> Black and white film is an power sensor. It simply
> measurses the power 


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Truman Prevatt said the following on 4/11/2004 6:11 PM:

> Black and white film is an power sensor. It simply measurses the power 
> (it counts photons) at a location on the film. A CCD is a power sensor. 
> It only counts the photons at a location. The only reason it can 
> measures red or green is there is a filter in front of it that filters 
> one all but one single frequency photons. Light is not only made up of 
> three frequencies - it is a continuum with the visible spectrum being 
> from a little above IR to a little below UV.
> 
> So the question is how well can one predict the actual energy on a pixel 
> per pixel basis using only pixels from there discrete frequencies.
> 
> It is a very easy experiment to run and it has been run many times. Take 
> a CDD without any color filter and measure an image. Measure it with 
> three sensors one with red, green and blue filters. Now take the entire 
> scene and minimize the error of the between a weighted combination of 
> the R, G and B sensors and the output of the CCD without any color 
> filter. There is a set of weights that minimize the error, but the error 
> will not be zero. That is the information lost.

...
Consider another experiment. The image being recorded consists of two 
halves -- one red, one green. The intensity of each half just happens to 
be such the the power sensed by the B&W CCD or film being tested is the 
same for each half. The resulting image will be an even shade of grey. 
Information has been lost, because the sensor throws away all 
information regarding the frequency of the photons. The RGB filter also 
loses some of the frequency related information -- but not all of it.

The information that the eye/brain needs to process an image includes 
both power and frequency. The RGB filter loses some information related 
to the total power over a given area -- but in return it gains some 
information related to the frequency (color). A pure B&W capture loses 
almost all information related to frequency -- the more so if the sensor 
has flat response across the spectrum.
-- 
Clive
http://clive.moss.net

Editor P.O.V. Image Service writes:

> Wide in the sense that it is "spectrally wide," yes.  But shooting B&W
> digitally is much like converting a color slide to B&W...

Identical, from an information-processing standpoint. That is, both have
the same serious drawbacks.

A pure B&W digital camera would produce very nice B&W indeed, since CCDs
are naturally good at monochrome capture, and the absence of color
filters would eliminate the resolution loss and some of the aliasing
that occurs in color digital cameras.  Unfortunately, there seems to be
no demand for a pure B&W digital camera, so none exists.  And since
there's no such thing as interchangeable image sensors (and probably
never will be, since that would partially kill the golden goose that
digicams represent for manufacturers), there may never be a true black
and white digital camera.

> The exposure latitude, or number of exposure zones, representable is
> VERY narrow, when compared to B&W film..

Under ideal conditions, CCDs can record 17-18 stops.  That requires
large photosites and a carefully designed chip with carefully designed
support electronics, though, and the CCD must also be actively cooled to
preserve shadow detail.  It's not really practical in ordinary digicams,
and so the average digicam actually turns out to have less range than
B&W film.  It's hard to beat the simplicity of a piece of plastic with a
light-sensitive coating.

Jeff Magidson writes:

> On practical terms how would the resulting images be Inferior?

Inferior in the sense that the range of different results you can obtain
from converting color images to grayscale is far, far smaller than the
results you can obtain by shooting black and white directly.

For example, if you shoot a scene through a narrow-band yellow filter in
straight black and white, you get results that are impossible to obtain
through any conversion of a color image.  If the original scene includes
both objects that are spectral yellow in color and objects that are
green and red in color, all of them will look white in the converted
color image, whereas only the truly yellow objects will look white in
the image shot through a filter with true B&W film.  This can make a
dramatic difference in the results you obtain.

> Would anyone but the photographer say " wow.. these are inferior
> photographs and must have been made with a digital camera or on color
> film and converted to B&W rather than shot on B&W film" ?

Non-photographers might not say that, but they'd still notice in some
cases.  Converted photos typically lack "pop" as compared to straight
B&W.

Black and white photography is about intensity - it throws away 
frequency on purpose.  That's why we do it, if I cared about frequency, 
I do color. However, a red filter (or green filter) change the gray 
scale by changing the power to the sensor.

Truman

Clive Moss wrote:

>
> ...
> Consider another experiment. The image being recorded consists of two
> halves -- one red, one green. The intensity of each half just happens to
> be such the the power sensed by the B&W CCD or film being tested is the
> same for each half. The resulting image will be an even shade of grey.
> Information has been lost, because the sensor throws away all
> information regarding the frequency of the photons. The RGB filter also
> loses some of the frequency related information -- but not all of it.
>
> The information that the eye/brain needs to process an image includes
> both power and frequency. The RGB filter loses some information related
> to the total power over a given area -- but in return it gains some
> information related to the frequency (color). A pure B&W capture loses
> almost all information related to frequency -- the more so if the sensor
> has flat response across the spectrum.
> -- 
> Clive
> http://clive.moss.net
>

-- 

We imitate our masters only because we are not yet masters ourselves, 
and only

because in doing so we learn the truth about what cannot be imitated.

 



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

Joe, I believe that if you use the unsharp mask in RGB, then select fade >
luminosity in the edit menu, you'll get the same result without any loss
incurred in switching back and forth to another mode.

Mike

From: "Joe Dempsey" <jdempsey@...>
Reply-To: DigitalBlackandWhiteThePrint@yahoogroups.com
Date: Sun, 11 Apr 2004 15:21:08 -0500
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Subject: RE: [Digital BW] On film


If you use Photoshop, correct the image the best you can in RGB and then
convert the image to LAB color by going to Image>Mode>Lab color.. LAB color
separates the image into three channels. Lightness (isolates all the detail)
and isolates the color in channels A & B ... (Hence L-A-B Color). Once you
have converted to Lab color, go to channels and click on the lightness
channel and lo, you get a BW image with all the detail and none of the
color. Then make your corrections with levels and curves in that order.
Avoid the brightness and contrast controls ... they destroy information ...
levels and curves does not.

Once you are satisfied with the image, sharpen it if you care to and save it
as (image number or name-BW. The you can reopen your existing image and
convert back to RGB and it is as it was before you started working on it. I
have also used the Fred Miranda Black and White Workflow Plug-in with some
success for converting RGB to BW. NEVER convert to BW by merely converting
the mode to grayscale. You let the computer interpolate what it thinks the
BW shades of gray should be and I trust my eyes more than I do the
processor. One further hint. As of late, I have been converting my color
images to LAB and selecting the lightness channel for sharpening and am
getting better overall appearance. After sharpening, I convert back to RGB.

Hope this helps,
Joe
 -----Original Message-----
 From: cirkutguy [mailto:cirkut@adelphia.net]
 Sent: Sunday, April 11, 2004 3:06 PM
 To: DigitalBlackandWhiteThePrint@yahoogroups.com
 Subject: Re: [Digital BW] On film


 --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Anthony G.
 Atkielski" <anthony@a...> wrote:
 > Most of the renditions are impossible in color conversions, because they
require information missing from a color image.

 I'm curious as to what information is missing from the color image
 that would be in the black and white. I too find that I often can't
 match the look of black and white film with a color conversion, but
 have always assumed that some amount of messing around would do it.

 Mark





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



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

I read on dpreview in one of the IR threads that there is someone who, for a
fee, will convert your Canon 10D to a dedicated black and white camera.
Evidently, he does some surgery on the camera, removing the AA filter and color
filters or something along those lines (possibly even replacing the sensor with
a new unencumbered one?). I didn't bookmark the article, because I will never do
something like this. But the point is that people out there are doing it and
making the service available.

On Mon, 12 Apr 2004 09:19:59 +0200, you wrote:

> there may never be a true black
>and white digital camera.

Victor Engel
lights@...

yes, but each film responds to different colors differently and with 
a CCD you get to choose (with all the inherent losses etc... I am not 
arguing on that score) which makes it much more flexible in your b&w 
rendition options.

As to film vs. digital for b&w I have gone back to shooting film... 
but that is more because I have some film cameras that I prefer to 
the available digitals.

mark

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Truman Prevatt 
<tprevatt@m...> wrote:
> Black and white photography is about intensity - it throws away 
> frequency on purpose.  That's why we do it, if I cared about 
frequency, 
> I do color. However, a red filter (or green filter) change the gray 
> scale by changing the power to the sensor.
> 
> Truman
> 
> Clive Moss wrote:
> 
> >
> > ...
> > Consider another experiment. The image being recorded consists of 
two
> > halves -- one red, one green. The intensity of each half just 
happens to
> > be such the the power sensed by the B&W CCD or film being tested 
is the
> > same for each half. The resulting image will be an even shade of 
grey.
> > Information has been lost, because the sensor throws away all
> > information regarding the frequency of the photons. The RGB 
filter also
> > loses some of the frequency related information -- but not all of 
it.
> >
> > The information that the eye/brain needs to process an image 
includes
> > both power and frequency. The RGB filter loses some information 
related
> > to the total power over a given area -- but in return it gains 
some
> > information related to the frequency (color). A pure B&W capture 
loses
> > almost all information related to frequency -- the more so if the 
sensor
> > has flat response across the spectrum.
> > -- 
> > Clive
> > http://clive.moss.net
> >
> 
> -- 
> 
> We imitate our masters only because we are not yet masters 
ourselves, 
> and only
> 
> because in doing so we learn the truth about what cannot be 
imitated.

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