The "A" Series Cameras
A selection of A Series cameras from my collection. On the left is the A-1 with the Motor Drive MA attached. This is a beautiful mint copy. In the back row, from the left, are the AE-1 in chrome, the AE-1 in black and the AV-1. Front row ,from the left, are the AL-1, AT-1, and the AE-1Program. I have an example of each camera in the series but still have some black copies to track down.
The “A” cameras represented a complete overhaul of Canon’s line of SLR cameras. Controlled by a micro computer in the camera, a new innovation at the time, the “A” series, the AE-1, AT-1, A-1, AV-1, AE-1P and the AL-1, changed the face of consumer cameras. These were also the first Canon Cameras to require a battery to operate. Automatic exposure had arrived.
The cameras were all of aluminum alloy body with an injection molded acrylonitrile-butadiene-styrene (for this read “plastic”) top cover. Canon went to pains to conceal the use of plastic by giving this top cover either a satin chrome or black metallic feel and finish. They were never intended as “pro” cameras but rather were aimed at the newcomer market. The “A” series were the first SLR’s purchased in the millions.
Extensive use of automation, simplified design and the use of less expensive parts, all making for an easy to use camera of considerable sophistication that was affordable was a winning combination. With this camera series, Canon was on the way to overtaking its old nemesis, Nikon.
“A” Series Cameras and their Introduction Dates
|AE-1 (Chrome)||1976||AV-1 (Black)||1979|
|AE-1 (Black)||1976||AE-1P (Chrome)||1981|
|AT-1 Chrome)||1977||AE-1P (Black)||1981|
|A-1 (Black)||1978||AL-1 QF (Chrome)||1982|
|AV-1 (Chrome)||1979||AL-1 QF (Black)||1982|
Starting with the AE-1 Canon started down the road to fully automatic cameras. But that was a slow evolution in features through many models of camera. This is a good point to look at some of the terms and processes that come up when discussing this evolving technology.
“Through the Lens” (TTL)
At first cameras had no means of measuring light. That was done by guessing and experience and then by light meters. When I started taking pictures in the 1950’s I had a light meter which I carried with me. Then cameras came out with a light meter attached to them. And finally the light meter was built into the camera body. The Canon rangefinder Model 7 had such a light meter. So did the Canonflex RM. But these light meters could not see what the lens saw. They measured light coming from the general direction the camera was pointing. In most cases this was enough but in some it was not.
In April of 1965 Canon introduced the Pellix camera in which the light meter was actually inside the camera measuring the light that arrived through the lens. This was the the beginning of what was to become the standard across the industry: true Through the Lens (TTL) metering.
On early cameras the shutter and/or aperture were set by the operator. When light meters were first mounted on cameras they were still not part of the work flow. They measured the light but they did not communicate with the camera. The photographer still set the shutter speed and aperture based on the light reading. Even with the first TTL light meters, the exposure was still set manually. It was with the AE-1 that the camera actually took part in setting the exposure.
Aperture Priority is an exposure method employed on modern cameras. In this mode of exposure setting, the lens Aperture is set by the photographer and then the shutter speed is adjusted automatically by the camera to obtain correct exposure. On Canon cameras this setting is indicated by “Av” (Aperture Value) on the selector dial.
This allows the photographer to control his depth of field himself and not leave it to the camera.
With Shutter Priority the shutter speed is set by the photographer and the Aperture is adjusted for correct exposure. This setting is indicated by Tv (Time Value) on the selector dial.
This would be used, say, in sports photography where the photographer wants to ensure a high shutter speed in fast moving situations. Once set, the camera will not try to change it. It will adjust the incoming light with just the aperture setting.
Program Mode simply means that the camera itself will set the shutter or aperture, or both. On Canon cameras this setting was indicated by the letter P (for Program). It operated in a slightly different manner on various models but it always involved the camera selecting at least one of the variables itself.
On Canon cameras this is indicated by a green rectangle on the selector dial. In this mode the camera selects all the variables by itself, automatically, without intervention from the photographer. Most experienced photographers stay away from this mode of operation because they want more control over their pictures. However, for inexperienced customers who want to be able to shoot “snapshots” without having to learn a bunch of controls and theory, this mode is a blessing.
Manual mode is indicated by an M on the selector dial and in this mode the operator selects all of the settings himself and any programmed or automatic features are disabled.
You may come across the expression “PASM” which is simply an acronym for Program, Aperture Priority (Av on Canon), Shutter Priority (Tv on Canon), and Manual. It means that the camera offers all of these basic modes of exposure.
Not only are there different modes of auto exposure, but there are different ways in which the cameras measure the light. The lens takes in a scene but what part of that scene is actually measured? Well, that depends.
If the light is measured towards the center of the scene, with most emphasis taken from the center and less influence taken from the edge of the scene, the method is called center-weighted metering. This was an early method of metering and it is the only mode found on many older cameras.
Spot metering is exactly what it says: a spot is chosen in the scene and the measurement is taken from it. This allows for very precise measurement of an area so that you can chose what in the scene is recorded in the most detail. This is favoured by people who like to exercise maximum control over the image. It is useful, for instance, in a strongly back lighted image. It allows you to set the exposure for the foreground image which may be in shadow.
Partial metering is like spot metering except the spot that the camera samples is larger.
Evaluative metering is Canon’s term. Nikon uses “matrix metering” and Pentax and Sony use “multi-segment metering” to describe the same thing. The viewfinder is divided up into zones and measurements are taken for each zone. The recommended exposure is then weighted towards the zone nearest the chosen auto focus point.