Canon T80

The Canon T80, introduced in April 1985 and discontinued in June 1986, was Canon's first autofocus 35mm single-lens reflex camera. It was part of the T series of FD mount cameras, and is not compatible with Canon's later EOS system and its autofocus EF-mount lenses. Instead, three special lenses, designated "AC", were produced for the camera. Other FD-mount lenses could also be used, but without autofocus capabilities.

Autofocus

The autofocus system in the T80 worked in the same manner as the focus assist system built into the earlier AL-1. A linear CCD is used to detect contrast in the focus area. When this area has the maximum contrast, the lens is in focus. This is a similar mechanism to that used in compact digital cameras. When a non-autofocus lens was used, the camera provided focus assistance in exactly the same manner as the AL-1.

The autofocus lenses contained a motor, and electrical contacts in the lens mount connected this motor to the camera's circuits.

Auto exposure and scene modes

Except for its autofocus capability, the T80 was very similar to the earlier T70, with four programmed scene modes in addition to regular Program auto-exposure (AE). These were:
* Deep Focus - the camera chooses a narrow aperture in order to get more depth of field. Useful for landscapes, or other situations when the photographer needs to get everything in reasonable focus. Trades off against a slow shutter speed.
* Shallow Focus - the camera chooses a wide aperture to get a shallow depth of field. Useful for portraiture, to reduce background distractions.
* Stop Action - the camera chooses a fast shutter speed so that movement is stopped. Useful for sports, wildlife, children etc.
* Flowing - the camera chooses a longer shutter speed for deliberate motion or panning blur.
* Program - the camera has more freedom of choice. Tends to prefer reasonably quick shutter speeds for minimal blurring.

Film transport

Film transport in the T80 was completely automatic, just as in the T70, in both directions. This left the top of the camera very clean, since there was no advance lever or rewind knob. Film loading was automatic; the user only had to align the film leader with an orange mark and close the back, and the camera loaded and advanced the film automatically. Indicators on the top LCD displayed the status of loading, winding and rewinding. The motor, and the camera's other functions including the focussing motor in the lens, were powered by 4 AAA batteries housed in the base of the camera.

AC lenses

Three special autofocus AC lenses were produced for the T80. Each lens contained a motor to focus, unlike the body-integral AF system pioneered by Minolta. All are readily identifiable by a boxy area on the upper left (viewed from the camera) containing the motor, and a red ring around the front lens element. The lenses were:

* AC 50mm f/1.8
* AC 35-70mm f/3.5-4.5
* AC 75-200mm f/4.5

All three, like the T80 itself, were only produced for a short time and are rare. The auto-focus function does not work on any other camera, although they can be used as manual-focus FD lenses. However they lacked aperture rings, so they were only useful on FD camera bodies that could control the aperture from the body.

Canon, unlike Minolta and Nikon, was convinced having the motor in the lens was the correct approach; this line of thinking continued with the new EOS system in 1987 and is still the case today.

Data back

A "Command Back 80" was available for the T80. Like the similar back available for the T90, it supports date stamping of images, alphanumeric coding of images, time exposures and time-lapse interval exposure.

References

* [http://www.mir.com.my/rb/photography/companies/canon/fdresources/SLRs/canont80/index.htm Canon T80 Camera] at [http://www.mir.com.my/rb/photography/ Photography in Malaysia] .