Introduction
To obtain the best possible results from your
Autorange 820 please study the following instructions
carefully. Before loading the camera with film it is also
a good plan to try the various controls, as described
later, in order to obtain the 'feel' of the
instrument.
The Autorange 820 is a fully coupled rangefinder model
incorporating a specially computed Ross Xpres lens and an
entirely new principle in camera focussing, designed to
obtain the highest possible optical performance. All four
components of the 105 mm. Ross Xpres f/3.8 lens are fixed
in order to obtain maximum resolution and the focussing
movement from the rangefinder is transferred directly to
the camera baseboard. In Fig.
1 part of the camera has been cut away in order to
show the principle of operation; the controls shown in
this illustration should be carefully memorised, as
constant reference to these items will be made in the
following instructions.
Operating the
Camera
To open the camera hold it in a vertical position but
tilting forward slightly and press on the baseboard
release catch. The baseboard will slide gently forwards
and lock in the ready position automatically.
With the camera open and using both hands to hold it,
the action of the combined rangefinder and viewfinder
should be studied. Slight variations in the method of
holding the camera are perfectly permissible, but
particular care must be taken to avoid obstructing either
of the rangefinder windows with the fingers.
Until some practice has been obtained in using the
rangefinder, it is best to focus on a subject in which a
straight line appears in the centre of the viewfinder.
For example, the camera could be directed towards the
straight edge of a window frame or a door.
Looking through the eyepiece at a scene, it will be
found that a small circle appears in the centre of the
frame with an illuminated rectangle surrounding it. The
double image in the centre of the frame must be made to
merge into one by rotating the rangefinder wheel. When
this has been done, the lens will be set automatically at
the precise distance of the subject from the camera and
if required, this distance may be read off from the
distance scale. The illuminated rectangle indicates the
field of view when taking 8 on 120 and the short lines on
the inside of this rectangle show the field of view when
taking 12 on 120 (6 x 6 cm.) pictures. One of the special
features about the viewfinder on the Autorange 820 is
that detail outside the picture area may also be seen; a
great advantage for action shots. The depth of field
table immediately above the rangefinder wheel indicates
the limits of sharp focus at different distances with
various lens apertures.
Loading the
Camera
The Autorange 820 will take either eight pictures or
twelve pictures on either 120 or 620 roll film. For
taking twelve pictures 6 x 6 cm. square, the hinged
masking plates inside the spool chambers must be brought
into action by rotating the two plates round the film
rollers until they are in position across the sides of
the picture aperture at the back of the camera. If,
however, it is decided to take eight pictures the masking
plates must be left inside the spool chambers.
Adjustments to the masking plates must be made before the
camera is loaded with film.
When using 120 film, it is important to use an empty
120 take-up spool which has a thick inner core. Similarly
with a 620 film an empty 620 take-up spool which has a
thin inner core must be used. Never try to wind 120
film onto a 620 spool or vice versa.
To open the camera back for loading a film, open the
back by releasing the catch, and lift out the loading
cradle immediately below the carrying handle by raising
the catch until the cradle moves out of the chamber.
Drop a spool of new film into the cradle, but do not
break the gummed strip which holds the paper leader in
position until later. See that the tapered end of the
paper leader points towards the empty take-up spool.
If an empty spool of the correct type is not already
in the take-up chamber on the opposite side of the
camera, pull the winding knob away from the body of the
camera until it can be turned and locked in the open
position. Then swing the loading cradle clear of the
camera body, as previously described, and drop an empty
spool into the cradle.
Push the cradle home, release the winding knob and
turn it until the slotted end engages the keyway of the
empty spool.
When an empty spool and a new spool of film have been
fitted in position, break the gummed strip which holds
the paper leader in place and draw the tapered end of the
paper leader straight across the back of the camera.
Insert the tapered end in the wide slot of the empty
spool and give the film winder knob one or two turns in
the direction indicated by the arrow to draw the paper
taut. It is particularly important, however, to see that
the paper leader runs freely across the back of the
camera and any misalignment must be corrected before
closing the back. Loading should always be carried out in
subdued light and never in direct sunlight.
Using the
Controls
Finally, close the back of the camera and see that it
is firmly locked by the catch. Before attempting to take
a picture uncover the appropriate ruby window in the back
of the camera, by sliding the safety cover to one side
and turn the film wind knob until first a warning hand
and then the number 1 appear. Except when winding the
film after each exposure, the ruby window should be
covered by the metal safety shield. This precaution is
especially important when using panchromatic films.
The required lens aperture is set by moving the
setting lever across the aperture scale plate.
To set the shutter, which determines the duration of
exposure, it is only necessary to rotate the
shutter-speed setting ring until the required speed is
opposite the index mark and then to move the
shutter-setting lever across the slot until it stops, in
order to set the shutter for an exposure.
For taking brief exposures set the shutter to B and
move the shutter-setting lever in the ordinary way. The
shutter leaves will open as the the release is operated
and close immediately the pressure is removed.
For time exposures, set the shutter to T and move the
setting lever as previously described. The cable release
supplied with the camera should then be screwed into the
socket at the side of the shutter. The first pressure on
the release will open the shutter (the leaves will remain
open after the plunger is released) and the next pressure
will close the shutter again. The camera should, of
course, be fitted on a tripod when making a time (or
brief) exposure.
Important
The shutter mechanism is coupled to the film in such a
way that after a picture has been taken another exposure
cannot be made until the film has been wound on ready for
the next picture. If, therefore, the shutter release
should appear locked, the reason will almost certainly be
that the film requires to be wound on to the next
number.
After the last exposure on a roll of film has been
made, wind on the film until the paper leader disappears
from the view in the ruby window, open the camera back,
remove the exposed film, fasten the end of the paper
leader with the gummed paper provided and transfer the
empty spool to the opposite film chamber.
Flash
Synchronization
Two standard coaxial-type sockets are built into the
side of the shutter. The socket marked "X" is for use
with electronic flash equipment and the socket marked "F"
is for use with class F or M bulbs. Flash synchronization
will be obtained at all shutter speeds when using
electronic flash equipment, at 1/50 sec. or below with
class F bulbs, and at 1/25 or below with class M
bulbs.
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