Los Angeles herald., 1910-10-09
THE ART AND PAsTlME
OF PHOTOGRAPHY

by some workers with hand cameras
that are not of the fixed" focus va
riety would be avoided if the users
would take the little trouble necessary
to discover what the conditions are
that result in this feature, applying
them to their own instruments when
it is desired to secure good definition
of all objects from ten feet outward
at one and the same time.
In order to secure this in the or
binary hand camera, either of the fold
ing or box form, it is necessary to re-
strict the size of camera and lens to
the 3AxA, or at the outside 4x5-inch
picture as the shorter the focal length
of the lens the easier it is to achieve
sharpness of definition without resort
ing to the use of small diaphragms or
stops. A 3Ax4A or 21sX4h box camera
will be usually found to contain lens
of 4A to 5-inch focus, which When
stopped down to the aperture OF Eli
or F12, such as most of them are, VIII
render sharply objects as near as 10
feet and from that outward to 100 feet
and over. This, except under the best
possible light requires an exposure not
faster than 1-10 second so that the
shutters on such cameras are made to
give about that when set for the So
called snapshot"
1t will be noted that at such speed
any jerkiness while exposing will
probably result in blurred negative
for lack of absolute stiffness on the
part of the user. Now take one of the
popular folding cameras, such as the
Kodak, Hawkeye, etc., fitted with
rapid rectilinear lens having adjustable
diaphragms opening to as large an
ING fd
scaled in the uniform system NO. 4,
we see at once that the aperture is
much larger than in the box camera.
This allows twice as rapid an exposure,
but at the expense of the Sharpness OF
definition for near objects when focused
for distance and vice versa.
We should find by trial that now the
nearest object sharply rendered when
lens is set at the 100-foot line, would
be as far off as 25 feet, farther by 10
feet than in the former case. Ii our
desire is to gain the same sharpness
we can do so by reducing the d1a-
phragm size to No. size and sun
better can be obtained by using the
No. 16 diaphragm. In this latter case
the sharpness will De moved backward
G. e., nearer to the lens), so that OBJ
jects at 10 or IL feet will also be sharp.
But we have now reduced our aperture
so much that the same rapidity of ex-
pOSure is no longer SaIe ana must Ue
decreased by one-half for the No.
and one-fourth for the No. 16 stop.
For instance, if the shutter is set
for 1-100 second when we expose with
the No. stop, No. would require
1-50 second and M. 16 1-25 second, the
later models of Kodaks, ETC., are now
fitted with exposures bearing such
markings. AS a matter of fact these
shutters are not nearly as accurate In
speed as they are marked, but that
matters comparatively little so long as
the relative speeds differ in the correct
ratio, so that the marked" 1-25 second
is one-q quarter as fast as the marked
1-100 second. The better grade of shut
ters, such as the Koilas, Compound
and Optimo patterns, are usually more
accurate in their speeds, as we'll as
giving much greater rapidity, and are
found on cameras fitted with the new
Anastigmats lenses that permit such
speed. Regarding exposures the fol-
lowing rules will save many an other
wise wasted exposure, namely, to give
as full an exposure as the subject will
permit and do not continually use the
1-100 second when 1-25 second would
give a chance to get detail in the
shadows, which after all are frequent
ly more important than the high lights.
which can be safely left to take care
of themselves. If you have one of the
newer models of the cameras already
mentioned try setting the lens and
shutter as suggested and apply the
checking scale on bed of camera so
that it focuses at the 50-foot or 100
md rncn1tS. If thew