9.10.
"DODGING"
319
subtracted from this; if the next harder paper is used, about 10 seconds
added.
A densitometer with a suitable photocell pickup can be a most useful
adjunct. The photocell should be in a small movable box, attached to
the amplifier with a cable, so that it can be moved about on the enlarging
easel and different parts of the image explored. There will be large fluctuations. One ordinarily determines correct exposure by what might be
termed "average background density." If the background exposure is
correct and the proper grade of paper is chosen, the rest of the image
will take care of itself. The amplifier and meter, of course, have to be
empirically calibrated beforehand so that one knows that a given meter
reading corresponds, for example, to a 30 second exposure with number
4 paper. The diaphragm of the enlarging lens is used to vary the illumination. Although such an instrument can insure that the basic exposure
will be correct, experience and judgment is still necessary to select the
proper contrast grade of paper and perhaps to "dodge" the image.
Simpler "photometers" can be adapted for enlarging purposes, but their
information is less accurate.
9.10. "Dodging"
The projection printing which one employs in enlarging offers considerable opportunity for controlling the image since not all parts need
to be exposed uniformly. Areas of high density may be given an unusually
long exposure so that they have gray tones on the finished print. Conversely, thin areas of the negative may be given brief exposures so that
their details are not lost in solid black in the print. This is accomplished
by "dodging" parts of the print with an out-of-focus mask.
The experienced operator usually can anticipate when an image will
need dodging. He will plan his program in advance and decide, perhaps,
that a central mass should receive 10 seconds less exposure than the main
picture. Then the central area can be blocked for 10 seconds during the
exposure by dodging it with a crudely shaped piece of cardboard fastened
to a wire. This is held between the enlarger lens and the enlarging paper
in an out-of-focus position so that the edge of the mask is completely
blurred. Tonal values can be further blended by moving the mask a bit
during the exposure. A corner or side area can be given additional exposure by masking the rest of the paper in an even simpler way. If a
mask with a single straight edge is all that is needed, a piece of card-
"DODGING"
319
subtracted from this; if the next harder paper is used, about 10 seconds
added.
A densitometer with a suitable photocell pickup can be a most useful
adjunct. The photocell should be in a small movable box, attached to
the amplifier with a cable, so that it can be moved about on the enlarging
easel and different parts of the image explored. There will be large fluctuations. One ordinarily determines correct exposure by what might be
termed "average background density." If the background exposure is
correct and the proper grade of paper is chosen, the rest of the image
will take care of itself. The amplifier and meter, of course, have to be
empirically calibrated beforehand so that one knows that a given meter
reading corresponds, for example, to a 30 second exposure with number
4 paper. The diaphragm of the enlarging lens is used to vary the illumination. Although such an instrument can insure that the basic exposure
will be correct, experience and judgment is still necessary to select the
proper contrast grade of paper and perhaps to "dodge" the image.
Simpler "photometers" can be adapted for enlarging purposes, but their
information is less accurate.
9.10. "Dodging"
The projection printing which one employs in enlarging offers considerable opportunity for controlling the image since not all parts need
to be exposed uniformly. Areas of high density may be given an unusually
long exposure so that they have gray tones on the finished print. Conversely, thin areas of the negative may be given brief exposures so that
their details are not lost in solid black in the print. This is accomplished
by "dodging" parts of the print with an out-of-focus mask.
The experienced operator usually can anticipate when an image will
need dodging. He will plan his program in advance and decide, perhaps,
that a central mass should receive 10 seconds less exposure than the main
picture. Then the central area can be blocked for 10 seconds during the
exposure by dodging it with a crudely shaped piece of cardboard fastened
to a wire. This is held between the enlarger lens and the enlarging paper
in an out-of-focus position so that the edge of the mask is completely
blurred. Tonal values can be further blended by moving the mask a bit
during the exposure. A corner or side area can be given additional exposure by masking the rest of the paper in an even simpler way. If a
mask with a single straight edge is all that is needed, a piece of card-