German industrial designer Luigi Colani, known for his use of biodesigns, was asked to rethink the camera. To do this, Canon engineers collaborated for the first time with an outside designer. In the 1980s, computerized cameras were becoming common and Canon felt they were becoming too complicated and difficult to use, necessitating a major redesign of the SLR camera. Variable shift program AE with 7 program options.Aperture priority AE with selectable safety shift function.Shutter priority AE with selectable safety shift function.Highlight and Shadow spot metering (based on the Olympus OM-4).Multi-spot metering (8 spots, based on the Olympus OM-4).A Highlight/Shadow control was offered in ½ increments for +/- 4 steps in certain modes. Exposure compensation could be set in ⅓ increments for +/- 2 steps.

An ISO range of 6-6400 was supported with ISO 25-5000 set automatically in ⅓ steps based on DX coding. Meter coupling range was EV 0-20 with ISO 100 film and an FD 50mm ƒ/1.4 lens. The camera used multiple silicon photo cells for through the lens ( TTL) metering. The T90 did not introduce any fundamentally new type of metering but it was the first time a single camera combined so many methods of metering.

The camera had a conventional pentaprism and interchangeable focusing screens. The camera could autoload film as well as read DX code information from the film can. A battery pack containing 4 AA cells powered the camera and the built-in 4.5 FPS autowinder. There was a 7 segment LED display visible in the viewfinder for shutter speed and aperture information and a 3 segment LED display for AE lock and metering information. It include a top mounted LCD panel with pictographic representation of the multiple metering modes, multiple exposure modes, shutter speed, aperture, and other settings. The T90 was the most sophisticated automatic exposure camera developed prior to modern DSLRs. Introduced in 1986, the Canon T90 was the last serious, high-end manual focus FD mount SLR designed by Canon.

Canon t90 manual