Canon Canonet 1 Service Manual page 65

6. H O W TO USE
6.1. The Lens Projection Test Unit without attachment shall be placed on a desk the surface of which is even,
screen being set right ahead of the desk. In this case, the Test Unit shall be made to face just toward the
screen with a space of about 1.5 m left. The screen shall be about 75cm x about 110cm in size.
6.2. The lens shall be opened to F l . 9 with the shutter kept to Time exposure.
6.3. The Lens Projection Test Attachment -2 shall be fixed in the back of the camera body by opening its back cover
so as to be stuck close to the rail. In this case, the center of the Test Attachment shall be trained right on
the optical center of the lens. In handling the Lens Projection Attachment, you must keep your fingers off the
plateglass, especially the test chart.
6.4. The Lens Projection Test Unit shall be switched on.
6.5. The camera body shall be maintained so that the distribution of light intensity through the camera in the test
position can be equivalent. In this case, a suitable holder may be used.
6.6. The helicoid of the lens shall be adjusted so that the test chart's image on the screen can be discerned most
clearly.
6.7. If the test chart is imaged equally on the screen both vertically and horizontally, then it may safely be said that
the lens is fixed properly to the camera body.
It is necessary, however, to note that tolerance, however slight it may be, is considered in proportion to the
ratio of photographing. Even if at first sight the lens is fitted in the camera body in the wrong way, sometimes
it need not be taken seriously if the ratio of photographing is taken into consideration in examining the image on
the screen.
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Fig. 2 The Diagram of ffie Test
4 8 12 16
C h a r t
a
18 20