| Sooner or later you will
want to make a copy of a color print. If you have the negative, it’s
an easy task. If you own a digital imaging darkroom (computer, scanner,
and printer) it is still an easy task. However, if you have to do it the
old-fashioned way, here are the instructions for doing the job in a conventional
darkroom.
Although it might appear to
be a simple matter of loading your camera with a nice low contrast film
and taking a picture of the original, I promise you, it is not that simple.
The main problem will be a marked increase in the contrast of the image.
You will lose some detail in both the highlights and the shadows. It won’t
be a pretty picture.
The correct way is to use a
technique that will lower the contrast of the copy film in order to preserve
the tone values in both ends of the scale--the highlights and the shadows.
The easiest technique which renders excellent results is to use a method
of very accurately flashing the film.
Since the amount of fog you
want to impart to the film is down around a fraction of an f/stop, it
isn’t a matter of simply stopping the lens down a bit or stepping
up the shutter speed. Instead, I use Kodak Neutral Density filters to
control the fogging exposure.
In order to be sure that I
don’t destroy highlight detail when I apply the fog, I intentionally
overexpose the film for the basic exposure.
Here’s how it works.
First, use a nice, slow, fine-grained film. The technique I’m going
to describe works the same with any camera. You can use a rollfilm camera
but I like my 4x5 studio camera. It produces a nice big negative that
gives me plenty of resolution. I have always used Kodak Vericolor III
film. It is currently available in 35mm, 120, 220, and 4x5 plus several
additional sizes.
For lighting, I use two electronic
flash units and shoot-through white umbrellas. I place the lights at about
a 45° angle to the original image. I do not like to use quartz-halogen
or other tungsten lights for color copy work. Their color temperature
drifts too much throughout their life for my tastes. Although it probably
doesn’t matter much when shooting color negative film. Still, the
5000°K color temperature of the electronic flash units is a nice match
for the daylight-balanced Vericolor film. By moving the lights further
from the original you will tend to improve the uniformity of the illumination
and eliminate hot spots. In any event, you will need a good light meter
that will allow you to measure the intensity of the lighting. Depending
on the size of the original, be sure to take enough readings to assure
yourself that the illumination level is within 1/5 of an f/stop throughout
the area of the original.
In order to have a built-in
color-balancing tool to assist when printing the color negative, I always
place a gray step tablet next to the original in such a way that I can
use it to help establish color balance. I can also easily crop it out
of the final production print. Choose a step tablet that is close to the
overall size of the original picture.
ND Filter Preparation
The exact amount of fog is controlled by the value of the ND filter. If
the original picture is relatively low in contrast, then you need less
fog to help keep the contrast a little higher in the copy. If the original
is normal or even high in contrast, then you need a little more fog in
order to help lower the contrast in the copy.
Try using these neutral density
filter settings as a starting point and modify them as your experience
indicates.
High Contrast Originals: ND filter 1.10 or 1.20 Normal Contrast Originals:
ND filter 1.30 Low Contrast Originals: ND filter 1.40 or 1.50
Since Kodak doesn’t make
filters in those exact values, you will have to combine two different
ones in order to make up the desired value. After combining the proper
filters, they should be permanently placed in a metal filter holder. This
will help to keep them from receiving excessively rough handling. Once
mounted, the new sandwich should be correctly labeled and stored in the
little envelope that the frame comes in. The new filter sandwich should
last for the rest of your life if you handle it carefully.
Original Preparation
If possible, remove any glass that might be covering the original. If
a vacuum frame is available, it can be used to hold the original flat.
If not, you can use a magnetic copy board, and place the magnetic hold-down
strips tightly against the edges (not overlapping the edges) of the original.
Do not attempt to clean the
original unless you are very sure of what you are doing. With old, fiber-based
photographs, film cleaners will frequently seep into the tiny emulsion
cracks and cause a discoloration that will be permanent.
Lighting Adjustments
If you are using Vericolor III (ISO 160) film, set your light meter to:
ISO 12. That is not a misprint. I use this setting because the film is
intentionally overexposed for this procedure.
If you are using a right-angle
sensing accessory for your light meter, be sure to use the proper correction
factor. Gossen Ultra-Pro meters require a correction factor of 3.0 when
used with their right-angle accessory.
Adjust the lights so that illumination
measurements taken at the surface of the original are within +/- 1/5 f/stops.
Be sure to measure all four corners and the center. Moving the lights
back will tend to reduce hot spots and improve uniformity. Using diffusion
softboxes or umbrellas will also improve uniformity of illumination.
Be sure to turn off all room
lights to eliminate stray reflections. Windows can also produce this effect
so they may need to be covered.
Whenever possible, remove any
glass that might be covering the original. If you must shoot through the
glass, it will be necessary to drape the front of the camera in black
(cloth or tape) to eliminate reflections. Also, be careful of the camera
stand that might be reflecting in the glass.
If the original has texture
to its surface (such as an oil painting), you may need to adjust the angle
of the lights very carefully, and/or use polarization over the lens and/or
lights to eliminate the spectral reflections.
Alignment Adjustment
Using a bubble level, check that the film plane of the camera is parallel
with the plane of the original. Turn the bubble level through 90° to be
sure that the alignment is true in both "X" and "Y" axis.
If you are copying an original
that is hanging on a wall, it will hang on a slight angle that might be
different from the angle of the wall. In any event, it needs to be checked
against the angle of the film plane in the camera. The proper tool for
this is called an "inclinometer." You can get such a tool from Edmund
Scientific Co., 101 E Glouchester Pike, Barrington, NJ 08007; (856) 573-6879.
Alternately, you might be able to use some type of carpenter’s leveling
tool from your local hardware store.
Gray Scale Use
Place a gray scale (step tablet) in the image area so that it will record
on the film along with the original image. The gray scale should be covered
with the white matte board along with the original image during the fog
exposure.
By later observing in the copy
print the very lightest and the very darkest steps of the gray scale you
will be able to know if you have captured the image at the optimum contrast
level. If you have shot bracketed fog levels you will be able to select
the exposure that produced the best contrast range.
The gray scale also helps to
establish color balance when you are ready to print the copy negative.
By observing the lightest gray steps in the copy test print, you will
be able to detect the presence of any improper color balance and correct
the printing filter pack. Of course, you should crop out the gray scale
in the final copy print.
Making The Exposures
Make the "main image" exposure first based on the meter reading that you
took. Then place the white matte board over the original, and while holding
the ND filter over the camera lens, make the fog exposure (as a "double
exposure" over the main one). The fog exposure utilizes the same f/stop,
shutter speed, and electronic flash settings as the main image exposure.
The ND filter controls how much fog is laid down on the film.
If you are in doubt about the
exact contrast level of the original, and therefore not sure of the exact
ND filter to use, you might want to make several bracketed shots using
different ND filters to produce different fog levels. Do not bracket the
basic image exposure established by using ISO 12 for a meter reading.
Some technicians like to throw the camera slightly out of focus during
the fog exposure to ensure that they will not be taking a picture of the
texture in the surface of the white matte board. If the white matte board
is perfectly smooth, this shouldn’t be necessary.
Process the film in a standard
C-41 process and print in a normal manner. It is likely that such a copy
negative will require slightly different enlarger filter settings than
a "regular" negative since it will be very overexposed.
If you’d like more help
with making color negatives from original color prints, or if you’d
like information on working with the new, digital imaging, darkroom tools,
you can send me your questions via e-mail at: editorial@shutterbug.net
or write to me care of Shutterbug.
Kodak makes several different
gray step tablets:
Kodak Q-53, Cat. No. 149-3485 (4" long)
Kodak Q-13, Cat. No. 152-7654 (8" long)
Kodak Q-14, Cat. No. 152-7662 (14" long)
They also make Neutral Density
filters in several different physical sizes and density strengths. Here
is a list of the ones you will need:
Kodak (75x75mm) ND filters in strengths ranging from 0.10 to 3.00. Since
these are acetate filters, I recommend that you get the Kodak metal filter
frames to mount them in.
Kodak Metal Filter Frame:
(75x75mm) Cat. No. 148-6638 You will also need a "fog reflector" for my
technique to work. The fog reflector is nothing more than a large piece
of smooth, white, (90 percent reflectance) matte board. It must be large
enough to cover the entire area of the picture you are going to copy.
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