Canon A-1

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Introduction

The A-1 is a 35mm SLR camera from Canon that, like its predecessor the AE-1, was innovative when released in 1978.

It was notable for its programmed automatic exposure setting, whereby both aperture and shutter speed are automated. While not labeled as such, it was a pioneer in offering the full "PASM" set of exposure options, standard in many later cameras through the present day. Canon's competitors were considerably slower in introducing programmed SLRs: Minolta in 1982 with the X-700, Nikon with the FA and Pentax with the Super A in 1983, and Olympus with the OM-2S Program in 1984.

The A-1 has the Canon FD bayonet/breechlock lens mount and was normally sold with the Canon FD 50mm f/1.8 or 50mm f/1.4 lens. The A-1 accepts any lens with the Canon FD (1971) breechlock mount or FDn (1979) bayonet mount. The more recent EF mount autofocus lenses (1987) cannot be fitted, nor can the FD mount lenses be fitted to autofocus Canon SLRs without an adapter.

The A-1 has several shooting modes: aperture and shutter priority automatic exposure, the first[1] "programmed" fully-automatic exposure mode, as well as automatic dedicated flash, and a fully manual setting. There is a numerical display in the viewfinder of shutter and aperture, using red LED seven-segment displays. To avoid fogging from the viewfinder on long exposures, the LED display can be switched off, and the eyepiece closed off with a shutter.

Description

The A-1 is a normally-sized SLR for its time (141 x 92 x 48 mm), but with a very large pentaprism and a removable "action grip" that fits over the battery door and provides a large textured area for the photographer to grip steadily; also, there is a large array of controls on the top, some of them quite unusual in appearance. All of these aspects combine to make the appearance of the camera, overall, rather bulky. The top is hard plastic coated in black enamel, and the bottom is brass covered in the same.

The control dial is more-or-less unique in the film-camera world, as it can be the shutter-speed dial or the aperture dial. It is shown (right) set to shutter priority auto ("Tv"). It is shrouded, with a small window showing it from the top and the rim projecting from the front of the camera, where the photographer's right index or middle finger naturally falls on it. A collar around the shutter release selects Av (aperture priority) or Tv (shutter priority). This moves a sliding crescent-shaped cover with an index mark on it that covers either the inner or outer ring of the control dial, revealing the other and pointing to the selected setting and that activates the corresponding autoexposure mode. The outer ring shows the shutter speeds (and "P"), and the inner ring shows apertures from f/22 to f/1.2 (not that these represent the full aperture range of the camera itself). In aperture priority mode the setting on the wheel is transferred directly to the aperture with the aperture wheel in the automatic position, and the shutter speed is chosen by the camera. The shutter speed priority mode works similarly, with the shutter speed being chosen by the dial and the aperture chosen by the camera. In Program mode, both aperture and shutter speed are set automatically. A graph showing the Program is given in the camera manual.[2] It is a straight line on a graph of aperture vs shutter speed (that is, both are adjusted at the same rate as the Light Value changes), until this becomes impossible when the lens reaches its maximum aperture; below this light level, the camera can only increase the shutter time.

A cover can be pushed up to prevent the control dial from being turned, for example to keep the camera from being taken out of program mode by accident.

At no time in automatic modes is the aperture ring turned by the photographer. In manual settings the required aperture is set on the lens and the shutter set on the dial, in the "Tv" position. The camera's selected settings will still be displayed in the viewfinder. No other metering is available for manual mode. Normal FD lenses cannot be metered in stop-down mode, but FL lenses require it.

On the photographer's left on the front is a peculiar slider, with a flip-up finger pad, which is the stop-down lever for depth of field preview and stop-down metering. If this lever is used, the shutter must be reset by recocking it; if the shutter has been released, DoF preview will not function correctly as the lens will not stop down past the aperture of the last exposure. If the shutter has not been released, it can be manually recocked by using the double-exposure lever. This is required, as the camera will not meter after previewing the aperture (displaying error code in viewfinder) until the shutter has been reset.

On the side of the lens mount are buttons for exposure preview (also available by half-pressing the shutter release) and exposure memory, which functions identically to the exposure preview except that once pressed, the exposure settings chosen will not change even if the light does. Around the rewind crank is the film speed setting dial, with ±2-stop exposure compensation adjustment. Both film speed and compensation are locked in place normally, with separate buttons to release each.

Next to the film speed/compensation dial, there is a button with a collar switch around it. The button tests the battery, with an LED on the opposite side of the camera that should flash somewhat rapidly if the battery is fresh. The switch deactivates the viewfinder display when pushed to the photographer's left.

The electronically controlled horizontal cloth focal plane shutter has marked speeds from 30 seconds to 1/1000, with X-synchronisation at 1/60 second (there is no bulb synch setting). In aperture priority mode the shutter speed is continuously variable. Even moderately well used examples of the camera (and the AE-1) develop a distinctive "squeal"; this can be corrected by re-lubricating the mirror braking mechanism. If this is not done, the fault can eventually lead to permanent damage. It is also not uncommon to see broken or taped-up battery doors on used models.

Dedicated flashguns can be attached to the hot shoe, where there are two additional contacts for camera-flash communication. There is also a PC socket on the front, near the rewind crank, for a conventional flashgun.

Around the wind-on lever is the On (A)/ Off (L, lock)/ self-timer (2 or 10 sec) switch, and also a double-exposure release that allows cocking the shutter without advancing the film (this is covered by the lever in the photo above). The base of the A-1 has electrical contacts and a mechanical linkage for a motor drive as well as the tripod bush and rewind release.

The A-1 was among the first cameras to be completely dependent on battery power. This power came from a 6V PX28A battery, or four LR44 1.5V alkaline cells, kept in a battery compartment on the front, partly hidden by the "Action Grip"[3]). The grip must be removed to fit a motor drive. Unlike most other Canon SLRs, the A-1 was only available in black finish.

Today

The Canon A-1 is superior to the AE-1 in most respects. The AE-1 has many plastic components. The A-1 was built more robustly, using metal gears in contrast to the metalized plastic gears of both the AE-1 and AE-1 Program. Furthermore, the A-1 offers aperture priority and lower shutter speeds, although the metering system is the same as that of the AE-1 Program. Despite its better specifications, the price of a second-hand A-1 is often lower. This may be because the AE-1's ubiquity and appealing style give buyers more awareness of it.

As a "user" camera today the A-1 falls in a bit of an awkward middle ground. It is a bit too complex and idiosyncratic to recommend to a complete film newbie. However, a photographer seeking a more automated experience may miss certain features, such as Program Shift, TTL flash control, or indeed, autofocus.


Notes

  1. According to Canon, in their museum
  2. The Program graph shifts with the film speed - the difference between Light Value and Exposure Value.
  3. named in the manual


Links

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Canon Cameras