Measuring Density Range

When speaking about Density Range....is the density range of any given image
measured from the darkest part of the image (highlight) to the lightest part
of the image? or to the clearest point of the film ie. just above base +
fog? What's the proper way to measure D.R.? Thx.

"Alan Smithee" wrote

When speaking about Density Range [what is it?]

This phrase does not have a fixed meaning [and when it comes
to sales claims for scanners and such it has no meaning at all].

As a caveat, on an image of a subject the darkest and the
lightest portion can not be measured because they are much
smaller than the measuring aperture of the densitometer.

Unarguably the darkest part of the negative is the high end
of the transmissive optical density (OD) range.

The other end can be, as you point out:

1) Air
2) The unexposed portion the film
3) The clearest portion of the image

Which you use depends on what you want to do:

1) use air as a reference if one is doing QA on film
and wants to measure the base/fog density
2) use the unexposed portion of the film because it
is easy to measure and that is what most everybody
does
3) use the clearest portion of the image if one is
trying to take densitometry measurements to determine
enlarging exposure in one swell flop

I would use the unexposed margin of the film to the
densest part of the image. The clearest portion of the
image [the part to make dead-black on the print] should
be very close in density to the unexposed portion of the
film unless it is a high flair situation or one is doing
drastic shifts in tonal range.

In my experience film density measurements only have relevance
when taking pictures of grey cards on cloudy days, the
inside of black cans with a pinhole at the other end
and other photometrological wastes of time [of which
I am very guilty].

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
To reply, remove spaces: n o lindan at ix . netcom . com
Fstop timer - http://www.nolindan.com/da/fstop/index.htm

Thanks for that Nick. The reason I'm asking is that I've only been doing B&W
about a year or so now. What is simple for me to accomplish in Photoshop is
a black art in the darkroom. Last night I was trying to do an enlarged print
which was a very contrasty scene, the subjects (people) were posed together
as a two-shot portrait style, one unfortunately was wearing a white shirt
illuminated by hard sunlight. When I "printed for highlight" their faces
became too dark for my liking. I went down to a grade 0 VC filter but still
not satisfied I ended up using Photoshop to produce the print (I had a
deadline). Inferior in resolution and detail but superior by virtue of the
fact that it let me cram the whole tonal range of the scene onto the print
out and fiddle with my middle tones until they looked right. When I looked
at the data (on the histogram) it really didn't look so formidable, but it
was obviously beyond the capability of my paper (or my talent) -- or was it.
I know I could dodge and burn away and get "something" but I'd rather be
able to just do a straight print from the neg and move on. I routinely
underdevelop these days especially if I'm shooting outdoors, but this was an
older roll. Is there a way to do contrast control on the camera using a
filter on the lens? I know large formatters don't suffer from this a much
because they can control development on each frame they shoot. What the
world needs is a B & W film emulsion that can be tamed by a filter on the
camera lens the same way a VC enlarger filter can change the paper, no?! Why
is this so hard to do?! Or does this already exist and I just don't know
about it? Thx.


"Nicholas O. Lindan" wrote in message
hlink.net...
"Alan Smithee" wrote

When speaking about Density Range [what is it?]

This phrase does not have a fixed meaning [and when it comes
to sales claims for scanners and such it has no meaning at all].

As a caveat, on an image of a subject the darkest and the
lightest portion can not be measured because they are much
smaller than the measuring aperture of the densitometer.

Unarguably the darkest part of the negative is the high end
of the transmissive optical density (OD) range.

The other end can be, as you point out:

1) Air
2) The unexposed portion the film
3) The clearest portion of the image

Which you use depends on what you want to do:

1) use air as a reference if one is doing QA on film
and wants to measure the base/fog density
2) use the unexposed portion of the film because it
is easy to measure and that is what most everybody
does
3) use the clearest portion of the image if one is
trying to take densitometry measurements to determine
enlarging exposure in one swell flop

I would use the unexposed margin of the film to the
densest part of the image. The clearest portion of the
image [the part to make dead-black on the print] should
be very close in density to the unexposed portion of the
film unless it is a high flair situation or one is doing
drastic shifts in tonal range.

In my experience film density measurements only have relevance
when taking pictures of grey cards on cloudy days, the
inside of black cans with a pinhole at the other end
and other photometrological wastes of time [of which
I am very guilty].

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
To reply, remove spaces: n o lindan at ix . netcom . com
Fstop timer - http://www.nolindan.com/da/fstop/index.htm

Alan Smithee wrote:

Thanks for that Nick. The reason I'm asking is that I've only been doing B&W
about a year or so now. What is simple for me to accomplish in Photoshop is
a black art in the darkroom. Last night I was trying to do an enlarged print
which was a very contrasty scene, the subjects (people) were posed together
as a two-shot portrait style, one unfortunately was wearing a white shirt
illuminated by hard sunlight. When I "printed for highlight" their faces
became too dark for my liking. I went down to a grade 0 VC filter but still
not satisfied I ended up using Photoshop to produce the print (I had a
deadline). Inferior in resolution and detail but superior by virtue of the
fact that it let me cram the whole tonal range of the scene onto the print
out and fiddle with my middle tones until they looked right. When I looked
at the data (on the histogram) it really didn't look so formidable, but it
was obviously beyond the capability of my paper (or my talent) -- or was it.
I know I could dodge and burn away and get "something" but I'd rather be
able to just do a straight print from the neg and move on. I routinely
underdevelop these days especially if I'm shooting outdoors, but this was an
older roll. Is there a way to do contrast control on the camera using a
filter on the lens? I know large formatters don't suffer from this a much
because they can control development on each frame they shoot. What the
world needs is a B & W film emulsion that can be tamed by a filter on the
camera lens the same way a VC enlarger filter can change the paper, no?! Why
is this so hard to do?! Or does this already exist and I just don't know
about it? Thx.


Hi Alan,

Negative Density Range is a slippery subject. For instance, and this may be the
kind of situation you faced last night, I may take densitometer readings and
find a density range of 1.50. (1) I can print for the highlights and find that
most of the image is in the low density values (like you did) and the print is
too dark. (2) I can just order in a lot of yellow filtration, and, as you
found, get a dull print, with too many gray tones. (3) I can remeasure the
density range, this time focusing only on the essential points of the negative -
the shadows and highlights on the face, if it is a portrait. Now, I may find
that the density range is only 0.80 for that region. I choose #2 or 2 1/2
filter and print. The face is right, but highlights in the back region may be
blown out. So, (4) I reprint, backing off a little on the time for the #2
filter, then change filters to #0 or #00 and expose to bring in the highlights.
This is called split filtration printing. After a while, it becomes a
standard tool, and you can start at step (3) above, skipping (1) and (2).

An alternative method is burning of highlights and dodging of shadows to control
the density in the print.


Francis A. Miniter

"Francis A. Miniter" wrote in
message ...
Alan Smithee wrote:

Thanks for that Nick. The reason I'm asking is that I've
only been doing B&W
about a year or so now. What is simple for me to
accomplish in Photoshop is
a black art in the darkroom. Last night I was trying to
do an enlarged print
which was a very contrasty scene, the subjects (people)
were posed together
as a two-shot portrait style, one unfortunately was
wearing a white shirt
illuminated by hard sunlight. When I "printed for
highlight" their faces
became too dark for my liking. I went down to a grade 0
VC filter but still
not satisfied I ended up using Photoshop to produce the
print (I had a
deadline). Inferior in resolution and detail but superior
by virtue of the
fact that it let me cram the whole tonal range of the
scene onto the print
out and fiddle with my middle tones until they looked
right. When I looked
at the data (on the histogram) it really didn't look so
formidable, but it
was obviously beyond the capability of my paper (or my
talent) -- or was it.
I know I could dodge and burn away and get "something"
but I'd rather be
able to just do a straight print from the neg and move
on. I routinely
underdevelop these days especially if I'm shooting
outdoors, but this was an
older roll. Is there a way to do contrast control on the
camera using a
filter on the lens? I know large formatters don't suffer
from this a much
because they can control development on each frame they
shoot. What the
world needs is a B & W film emulsion that can be tamed by
a filter on the
camera lens the same way a VC enlarger filter can change
the paper, no?! Why
is this so hard to do?! Or does this already exist and I
just don't know
about it? Thx.


Hi Alan,

Negative Density Range is a slippery subject. For
instance, and this may be the kind of situation you faced
last night, I may take densitometer readings and find a
density range of 1.50. (1) I can print for the highlights
and find that most of the image is in the low density
values (like you did) and the print is too dark. (2) I
can just order in a lot of yellow filtration, and, as you
found, get a dull print, with too many gray tones. (3) I
can remeasure the density range, this time focusing only
on the essential points of the negative - the shadows and
highlights on the face, if it is a portrait. Now, I may
find that the density range is only 0.80 for that region.
I choose #2 or 2 1/2 filter and print. The face is right,
but highlights in the back region may be blown out. So,
(4) I reprint, backing off a little on the time for the #2
filter, then change filters to #0 or #00 and expose to
bring in the highlights. This is called split filtration
printing. After a while, it becomes a standard tool, and
you can start at step (3) above, skipping (1) and (2).

An alternative method is burning of highlights and dodging
of shadows to control the density in the print.


Francis A. Miniter


I think your suggestion of printing using several contrast
filters _with masking_ is the best answer. Film is capable
of recording a much greater range of brightness than can be
reproduced on printing paper. If the overall contrast of the
paper is adjusted to fit the resulting print will look flat
because the eye wants "normal" contrast in the mid grays. By
combining burning and dodging with variable contrast its
possible to get good prints from "impossible" negatives. One
can do the same thing in Photoshop and it may seem easier
but for any sort of complex scene its painstaking either
way.


--
---
Richard Knoppow
Los Angeles, CA, USA

Alan Smithee wrote:

When speaking about Density Range....is the density range of any given image
measured from the darkest part of the image (highlight) to the lightest part
of the image? or to the clearest point of the film ie. just above base +
fog? What's the proper way to measure D.R.? Thx.




IMHO the most meaningful measurement is not negative density but the log
of the relative illumination in the projected image. Density applies
quite well to contact prints, but enlargements are subject to flare in
the enlarging lens and stray light from many possible sources which are
not accounted for in density measurements but do affect the illumination
range of the projected image.

If you are using teh manufactuer's speed ratings and development times,
these are typically excessive.

If you cut the ISO in half and cut development by about 1/3 you'll get
far better results.


Alan Smithee wrote:
Thanks for that Nick. The reason I'm asking is that I've only been doing B&W
about a year or so now. What is simple for me to accomplish in Photoshop is
a black art in the darkroom. Last night I was trying to do an enlarged print
which was a very contrasty scene, the subjects (people) were posed together
as a two-shot portrait style, one unfortunately was wearing a white shirt
illuminated by hard sunlight. When I "printed for highlight" their faces
became too dark for my liking. I went down to a grade 0 VC filter but still
not satisfied I ended up using Photoshop to produce the print (I had a
deadline). Inferior in resolution and detail but superior by virtue of the
fact that it let me cram the whole tonal range of the scene onto the print
out and fiddle with my middle tones until they looked right. When I looked
at the data (on the histogram) it really didn't look so formidable, but it
was obviously beyond the capability of my paper (or my talent) -- or was it.
I know I could dodge and burn away and get "something" but I'd rather be
able to just do a straight print from the neg and move on. I routinely
underdevelop these days especially if I'm shooting outdoors, but this was an
older roll. Is there a way to do contrast control on the camera using a
filter on the lens? I know large formatters don't suffer from this a much
because they can control development on each frame they shoot. What the
world needs is a B & W film emulsion that can be tamed by a filter on the
camera lens the same way a VC enlarger filter can change the paper, no?! Why
is this so hard to do?! Or does this already exist and I just don't know
about it? Thx.


"Nicholas O. Lindan" wrote in message
hlink.net...
"Alan Smithee" wrote

When speaking about Density Range [what is it?]

This phrase does not have a fixed meaning [and when it comes
to sales claims for scanners and such it has no meaning at all].

As a caveat, on an image of a subject the darkest and the
lightest portion can not be measured because they are much
smaller than the measuring aperture of the densitometer.

Unarguably the darkest part of the negative is the high end
of the transmissive optical density (OD) range.

The other end can be, as you point out:

1) Air
2) The unexposed portion the film
3) The clearest portion of the image

Which you use depends on what you want to do:

1) use air as a reference if one is doing QA on film
and wants to measure the base/fog density
2) use the unexposed portion of the film because it
is easy to measure and that is what most everybody
does
3) use the clearest portion of the image if one is
trying to take densitometry measurements to determine
enlarging exposure in one swell flop

I would use the unexposed margin of the film to the
densest part of the image. The clearest portion of the
image [the part to make dead-black on the print] should
be very close in density to the unexposed portion of the
film unless it is a high flair situation or one is doing
drastic shifts in tonal range.

In my experience film density measurements only have relevance
when taking pictures of grey cards on cloudy days, the
inside of black cans with a pinhole at the other end
and other photometrological wastes of time [of which
I am very guilty].

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
To reply, remove spaces: n o lindan at ix . netcom . com
Fstop timer - http://www.nolindan.com/da/fstop/index.htm

Another thing you can do is a sub-threshold flash of the paper, this can
often salvage those highlights without changing tonality in the rest of the
print. (A bit like working over "curves" in photoshop.)

"Richard Knoppow" wrote in message
. net...

"Francis A. Miniter" wrote in
message ...
Alan Smithee wrote:

Thanks for that Nick. The reason I'm asking is that I've
only been doing B&W
about a year or so now. What is simple for me to
accomplish in Photoshop is
a black art in the darkroom. Last night I was trying to
do an enlarged print
which was a very contrasty scene, the subjects (people)
were posed together
as a two-shot portrait style, one unfortunately was
wearing a white shirt
illuminated by hard sunlight. When I "printed for
highlight" their faces
became too dark for my liking. I went down to a grade 0
VC filter but still
not satisfied I ended up using Photoshop to produce the
print (I had a
deadline). Inferior in resolution and detail but superior
by virtue of the
fact that it let me cram the whole tonal range of the
scene onto the print
out and fiddle with my middle tones until they looked
right. When I looked
at the data (on the histogram) it really didn't look so
formidable, but it
was obviously beyond the capability of my paper (or my
talent) -- or was it.
I know I could dodge and burn away and get "something"
but I'd rather be
able to just do a straight print from the neg and move
on. I routinely
underdevelop these days especially if I'm shooting
outdoors, but this was an
older roll. Is there a way to do contrast control on the
camera using a
filter on the lens? I know large formatters don't suffer
from this a much
because they can control development on each frame they
shoot. What the
world needs is a B & W film emulsion that can be tamed by
a filter on the
camera lens the same way a VC enlarger filter can change
the paper, no?! Why
is this so hard to do?! Or does this already exist and I
just don't know
about it? Thx.


Hi Alan,

Negative Density Range is a slippery subject. For
instance, and this may be the kind of situation you faced
last night, I may take densitometer readings and find a
density range of 1.50. (1) I can print for the highlights
and find that most of the image is in the low density
values (like you did) and the print is too dark. (2) I
can just order in a lot of yellow filtration, and, as you
found, get a dull print, with too many gray tones. (3) I
can remeasure the density range, this time focusing only
on the essential points of the negative - the shadows and
highlights on the face, if it is a portrait. Now, I may
find that the density range is only 0.80 for that region.
I choose #2 or 2 1/2 filter and print. The face is right,
but highlights in the back region may be blown out. So,
(4) I reprint, backing off a little on the time for the #2
filter, then change filters to #0 or #00 and expose to
bring in the highlights. This is called split filtration
printing. After a while, it becomes a standard tool, and
you can start at step (3) above, skipping (1) and (2).

An alternative method is burning of highlights and dodging
of shadows to control the density in the print.


Francis A. Miniter


I think your suggestion of printing using several contrast
filters _with masking_ is the best answer. Film is capable
of recording a much greater range of brightness than can be
reproduced on printing paper. If the overall contrast of the
paper is adjusted to fit the resulting print will look flat
because the eye wants "normal" contrast in the mid grays. By
combining burning and dodging with variable contrast its
possible to get good prints from "impossible" negatives. One
can do the same thing in Photoshop and it may seem easier
but for any sort of complex scene its painstaking either
way.


--
---
Richard Knoppow
Los Angeles, CA, USA