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.
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.
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.