Camera Operation, Opening the Camera

Figure 1-3 Opened for picture taking

The subject is viewed and focused throught the taking lens, a mirror, a Fresnel viewing screen (with spilt-image focusing aid) and a optical system to focus the image at the viewing eye- piece. As in all single-lens reflex cameras, the shutter must be open to provide an image at the eye-piece. This requirement is fulfilled by the automatic electro-mechanical components which are described in detail in Section II of this manual.

When the exposure is made, the image must be transferred from the viewing system to the surface of the film in accurate focus. To accomplish this, the shutter closes and the viewing screen swings out of the optical path which is then diverted by a mirror to the film surface. These two paths are described in greater detail elsewhere in this section.

The exposure is made following the viewing screen / mirror swing. The screen then returns to the viewing position and the automatic mechanism ejects the exposed sheet of film. development takes place outside the camera and can be observed by the operator. As soon as the print is ejected, the mechanism completes its

cycle to prepare for the next exposure. Following thenth exposure, the flash circuit is inhibited until a fresh film is inserted. Normal operation will resume when the camera is reloaded.

B. CAMERA OPERATION

The following paragraphs describe the electro- mechanical events that occur in normal operation. the purpose of this desciption is to acquaint the reader with the manner in which the various functions are accomplished. Detailed analysis at component / sub assembly level appears in Section II.

1. Opening the Camera

When the SX-70 is folded, an interlock switch (S6) removes all battery power from the camera mechanism to prevent any drain from the film pack encapsulaetd batteries. To prepare the camera for picture taking, hold the camera in the left hand, pull straight up on the serrated portion of the viewfinder housing (Figure 1-2). this action releases latches, which, in turn, allow the main body of the camera to raise into operating position.