Stopped-Down Metering - Canon F1-N Brochure & Specs

13.2 Stopped-down Metering

13 EXPOSURE MODES
[For this mode. the AE Power Winder FN or AE Motor Drive FN must be attached
to the camera and the lens set to the "A" mark.]
3. Aperture-priority AE
Set the lens to the desired aperture and the camera automatically selects the proper
shutter speed according to the lighting conditions. This AE mode is useful for
portraiture and still photography such as landscapes where depth of field is of im-
portance.
[For this mode, the AE Finder FN must be attached to the camera and the shutter
dial set to "A"]
13.2 Stopped-down Metering
Stopped-down metering is necessary whenever you are using a non-FD lens, such as
the Reflex 500mm, which has a fixed aperture, the TS 35mm lens or any of the older
FL lenses. It is also necessary whenever you insert accessories which do not have
a full-aperture signal pin, such as bellows or extension tubes, between the camera
body and lens. Stoppeddown metering is possible, though unnecessary, with an FD
lens. For correct exposure, set an aperture smaller than f/2.8.
For stopped-down metering, the lens diaphragm must be closed down (stopped
down) to the working aperture. Since the diaphragm will open and close as you
turn the lens'aperture ring, depth of field can be easily checked.
1. Stopped-down (Fixed-index) Metering
Set an aperture and unlock the stop-down slide by pushing it in and then releasing
it. Turn the shutter dial (or aperturering) until.the meter needle is in line with the
stopped-down metering index.
2. Stopped-down AE
Set an aperture and unlock the stop-down slide by pushing it in and then releasing
it. The camera will automatically select the proper shutter speed for the lighting
conditions.
This AE mode is especially advantageous in such fields as photomacrography and
photomicrography.
[For this mode, the AE Finder FN must be attached to the camera and the shutter
dial on "A."]
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