Canon AT 1 - Manual (Page 14)

Focusing Screen: Split-image/microprism
rangefinder surrounded by matte screen
Viewfinder Information: Meter needle and
aperture needle (circular index) are seen
on the right hand side of the viewfinder.
On the upper right hand is an over-
exposure/battery check index mark and
on the lower right hand is a metering
limit index mark on the underexposure
side.
Viewfinder Attachments: Angle Finder A2
and B, Magnifier S, Dioptric Adjustment
Lens S (10 kinds), and Eyecup 4S.
Mirror: Instant-return, large reflector mirror
with shock absorbing mechanism.
Exposure Meter: Built-in. Using CdS photo­
cell. Coupled to shutter speeds, film
speeds, and f/stops. Match needle type,
TTL full aperture metering mechanism.
Light Metering System: TTL (Through-The-
Lens) Central Emphasis Metering method
Exposure Meter Coupling Range: EV 3 (f/1.4
at 1/4 sec.) to EV 17 (f/16 at 1/500
sec.) at ASA 100 film with FD 50mm
f/1.4 S.S.C. Lens.
Film Speed Range: ASA 25 to ASA 3200