The Salt Lake herald. [volume] (Salt Lake City [Utah]) 1870-1909, 1900-03-09

be made either in the morning or after
noon.
For the first trial let US agree that a
house be chosen for the subject. Let
us suppose that the proper light is now
on the subject. We proceed by setting
up our camera on its tripod. 1t should
be so placed as TO be perfectly steady
The best way 10 secure the most desir-
able results and at the same time have
the tripod so that it will not interfere
with the movements Of the operator IN
focusing is to set up the tripod so that
one leg of it points directly toward the
object to be photographed. By this
means the remaining two legs viii be
in such a position that one may stand
between them in arranging the cam
eEa.
After the camera is in position and
the screw Of the tripod which holds the
camera has been tightly set, the cap is
taken from the lens, the shutter opened
by using the time exposure" and we
are ready 10 focus our picture on the
grounds glass screen at the back of the
camera.
The opaque focusing cloth is then
thrown over the back of the camera
and brought closely down over the
head in such manner a. 10 shut out
all possible daylight from the back Of
the camera. The only light We want is
that which comes through the lens at
the front.
Focusing is generally Ji0ne by means
of a screw at the front Of the camera,
which racks out or in, as the case may
be. thus increasing or decreasing the
distance of the lens from the screen.
This focuses the ray of light passing
from the object through the lens TO
the screen, making the picture clear
and distinct upon the glass. As the
picture becomes sharply focused upon
the screen, We notice first that it is re-
versed, or upside down. (The %easOn
for this is given in the chapter on
lenses.) We soon get accustomed to
seeing our pictures and focusing tnem
in this upside-down position
While focusing We have opened the
lens wide. and having now focused the
image on the ground glass as sharply
as possible, paying particular attention
to a point about one-third the length
of the plate, we must make use of the
diaphragms or stops.
IF our camera has a shutter the dia-
phragms are fixed in the shutter, and
either represent a revolving disk with
differentiated openings, or open and
close by means of little wings plvoted
together, called iris diaphragms.
II the camera mas no SHUTTER NAlAN
are termed waterhOuse dIaphragms are
used. These are sets Of metal plates
with openings Of different diameters
Any particular plate or diaphragm may
be placed in the H. diaphragm slot
which is cut in the lens for the purpose
One reason for selecting house or
building for a first trial of focusing the
image correctly on the plate is to
demonstrate the use Of the sliding front
and the swing back. If the camera is
set up perfectly level we viii probably
find that we have quite an expanse of
foreground. but only One-half or three
quarters Of the house Cor height on
the ground glass. This is caused by the
house being so much higher than the
camera. If one could ascend a plat
form that would place the camera on
a level with the center of the house this
trouble would be avoided, but this. OF
course, is impossible. The difficulty is
overcome by having the front of the
camera so that it can be raised or
lowered. There is a thumbscrew on
the side of the front of the camera.
This needs only TO be lOosened, when
the whole front can be raised to the