Canon A-1 Assembly instructions

Canon A-l Repair Guide

1. Introduction
In April, 1976, Canon introduced a landmark camera, the
Canon AE-l. It incorporated a very reliable computerized
AE mechanism into a compact body that can be marketed at a
very competitive price due to revolutionary production
techniques. The AE-l has been a huge success and completely
changed the face of photo hardware marketing.
With the AE-l firmly established as the best selling SLR in
the World, design work progressed on a more versitile ver-
sion. This work is now complete and the result is the CANON
A-l, the Apex of the AE camera world: the highest quality,
most durable, most feature laden automatic exposure SLR in
the world.
The major goals which guided the design of the A-l were:
- Incorporation of advanced digital technology
- Compact, easy-to-handle body
- Compatability with AE-l system components
- Interchangeability of parts with AE-l
- Improved durability
2. Features
2.1 Five difference automatic exposure modes
o
Full Aperture TTL Metering
Shutter speed priority AE
Aperture priority AE
Programmed AE
Electronic flash AE
o TTL Stopped-Down Metering
Stopped-down AE at (regardless of the types of lens
attached or whether a lens is attached at all).
2.2 The employment of total digital system to process with
speed and accuracy all incoming information
After converting the brightness information from analog
form into digital form, digital computation takes care of
information input, calculation, information storage,
1
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information display and exposure control.
2.3 Full Information Character Display Viewfinder
All information is displayed alphametricly is the dark area
below the focusing screen by segmented LED's similar to
those used in digital calculators. Information includes
exposure information, mode information, and various warn~
ings. Although it is probably the least intrusive full
information viewfinder ever built, it can be turned off to
completely eli m inate any distract io n to focusing and com-
position. Even when it is turned off, the camera continues
to function normally in whichever mode it is in. Details
are given later.
2.4 Expanded Range and Versitility
Expanded metering, film speed and shutter speed and ex-
posure compensation ranges, EV memory · and multiple exposure
increase the A-l's versitility.
2.5 Essential Controls and Displays Grouped for Easy Reach and
Rapid Operations
(1) AE mode
· (2) AT dial
(3) Shutter button lock self-timer lever
(4) Viewfinder information displ ay switch
(5) Multiple exposure lever
2.6 Automatic System Components
Motor Drive MA, Power Winder A, Data Back A, Speedlites
155A, and 199A.
2.7 Human Engineering, Miscellaneous
2
o Safety Features: Lock Mechanis m s, Flashing Warnings,
Energy Conser v ing Design
o Easy Operation: Action Grip, H uman Engineering
Design, Electro-magnetic release
o Interchangeable Viewfinder Screens

o Easy to ~ead viewfinder
o True-load b attery checker giv es visual indication
of remaining battery power
o Eyepiece Shutter to block extraneous light
o Two delay self timer
3. Specifications
3.1 Type:
35mm focal plane shutter single lens reflex with five
automatic exposures modes:
3. 2 Picture Size:
24 x 36 rom
3.3 Interchangeable Lenses:
3.4
Whole FD series for five methods in automatic exposures;
with FL series, automatic exposures with stopped-down
metering at working apertures.
Viewfinder
(1)
(2 )
(3 )
(4 )
(5 )
Type:
Field-of-view:
Magnification:
Viewfinder Power:
Focusing Screens:
Fixed eye-level pentaprism
93.4% vertical and 95.3%
horizontal
0.S3X at infinity with 50 rom lens
-1.0 dpt (same as the AE-l)
Standard screen is center split-image (2.5 rom di-
ameter with So prism angle) rangefinder surrounded by
microprism (with So prism) and ground glass/fresnel
field for the remaining portion. , The six focusing
screens for replacement are split-image, mlcroprism,
microp j."i sm for small aperture lenses, all matte,
double cross hair reticule a nd matte/scale.
(6) Viewfinder Information
Seven segment LED's provide six variable digits plus
an "Mil and a decimal paint. Information includes
Shutter Speed, Aperture, Flash ready information,
3

Manual indicat i on and flashing signals, in digital
form. The display can be turned off when not needed
without affecting the camera operation.
(7) Mirror Cut-off:
No mirror cut-off with telephoto lens as long as FD
400 mm lens.
(This is the same with AE-l.)
(8) Eyepiece Shutter:
Built-in
(9) Accessories.
Angle Finder, Magnifier, Eyecup, and eyesight correc-
tion lenses.
(The same as for the AE-l.)
3.5 AE Function
4
(1) Method
Electronicly controled automatic exposure by setting
the FD lens at the 'A' mark, and selecting the AE
mode with the AT dial to relay the input of exposure
control information.
(Three LSI with 12L, one linear LSI,and one Bi-Hos IC,
the latter for metering the light, are used.)
(2) Automatic exposure modes
AE Hode Meter in g
Shutter speed
Full aperture
priority
Aperture
stop
Full aperture
pr i ority
Prograaaed
Full aperture
AE flash
Full aperture
Stopped-down Stopped-down
.
Aperture R in g
AE Hode
AI Dial
Selector
Setting of Leos
Switch
Reading
'A' mark.
Tv
Shutter speed
'A'
.... rk
Av Aperture stop
' A'
mark
Tv
P
' A' mark
*Either
Tv
or Av
Any apert u re
Either
Tv or Av
except 'A'
*: For a shutter speed of 1/60
or slower with the 199A,
set the switch to Tv.

(3) Light Sensing Element
Center-weighted average meter reading (the same as the
AE-l) by a silicon photocell placed above the eyepiece
and fresnel lens to concentrate the incoming light.
(4) Meter Coupling Range
EV -2 (f/l.4 lens) to EV 18 with ASA 100 film. The
programmed AE program is shown by the dotted line.
5

30 15 8 4 2
AE coupling Range for ASA Film
Speeds with f/l.4 Lens
F
NO .
la
II
•
5.6
4
2.8
2
1.4
112 114 1/8 III' 1130 1160 VI25 11250 II!:IOO 1/1000
m

(5) Film Speed Range
ASA 6 to 12,800 in 1/3 step increments
(6) Exposure Compensation
Two full f/stop plus/minus control with figures from
1/4X to 4X and calibrations in 1/3 step increments.
The following shows the range of exposure variations
possible with the respective film speed setting:
ASA 6
ASA 12
ASA 25 -3200
ASA 6400
ASA 12800
1/4 • • 1/2 • 1
1/4 • • 1/2 • • 1 • • 2
1/4 • • 1/2 • • 1 • • 2 • • 4
1/ 2 • • 1 • • 2 • • 4
1 • • 2 • • 4
(7) Exposure Memory
There is a memory lock button (located where the
exposure compensatio n bu tton is ON the AE-l). While
this button is press ed , th e exposure reading is
locked and you are at your liberty to vary the com-
bination of shutter speed and f/stop.
(8) Stopped-Down Metering Lever
The lever is of folding type and by lifting the end
and pushing against the t ension of the spring, it is
locked in place.
(9) Other Operations
The AT dial has the following indications
>
<
..
..
...
-: •
C: • : • ..
o 0 0 '" 0 0 ."
a.. 0 0 W) N ~ M _
o II) N _
-
GO ...
GO
..
- ..
...
• GO
AV. Black figures in the yellow ground
p, Black in the green base
-
TV: 2" to 30": Yellow figures in a black ground
Other figures: White figures in a black ground
7

3.6 Power Source
8
(1) Battery
One 6V silver oxide battery (Eveready No. 544, UCAR
No. 544, JIS 4G13, or Mallory PX28) or alkaline man-
ganese battery (Eveready NO. 537, UCAR No. 537)
(This is the same with the AE-l.)
(2) Battery Chamber
Under the finger grip on the front of the camera body.
(This is the same with the AE-l.)
(3) Main Switch.
By setting the shutter button lock lever to "L", all
the ' electronic circuits will be · turned off.
(4) Battery Check
True-load Type
The flashing frequency changes depending on the con-
dition of the battery, roughly telling you how good
it is. The slower the flashing frequency, the weaker
the battery.
(5) Cancellation of the circuit
1) Set the shutter button lock lever to "L", or
2) Press the battery check button and take your finger
off the button.
The AE-l's circuit is ca ncelled the moment the
battery check button is pressed, while the A-l's
circuit is cancelled the moment the finger is
taken off the button. (To be more precise, the
A-l's circuit is cancelled when the battery check
button is pressed, but the battery checker current
thru the second shutter magnets give the impression
that the circuit is not cancelled.)
(6) Battery Life
The battery lasts for approximately 15,000 exposures
or one year under normal use.
Normal use means that the camera is used with shutter
speed at 1/125 sec and that the digital indications
are lit for one second at every exposure.)

3 . 1 ~h u t t er Mechanism
(1) Type
Dual roller type cloth focal plane shutter
(2) Speed
1) Scale on the AT dial
B, 30, 1 5,8,4 , 2,1,2,4,8,l5,30,60,125,250,500,1000
I I I I
Yellow White
(3) Shutter release button
o . Electromagnetic shutter release
Large-sized shutter button is concentric with th e
AE mode selector.
(4) Synchronization contact
o X synchronization is at 1/ 60 sec.
o The accessory shoe on the top of the pentaprism
has a direct flash contact. On the front of the
camera body is a PC flash terminal, (JIS-B type).
Wit h built-in electric shock preventive rim.
o The accessory shoe has an automatic flash control
contacts for automatically switching shutter spee d
and aperture.
o When using ordinary flash units (other than
Speedlite 155A and 199A) , set the AE mode selecto r
to Tv and set the sh u tter speed to 1/ 60 sec or
slower.
3. 8 Self-Timer
(1) Ty pe
Electronically controlled self-ti m er
(2) Operation
o Set the self-timer lever either to "2" or to " 10".
o Activated by the shutter release button.
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10
o The figures "2" and "10" mean that the self-timer
releases the shutter after a time lag of two and
10 seconds respectively.
o Press the shutter button only after closing the
eyepiece shutter, to block extraneous light.
The camera measures the light the instant before
ahutter release. (The AE-l measures before the
self-timer starts).
o After completing self-timer photography, return
the self-timer lever either to "A" or to "L".
(3) Cancelling the aelf-timer operation
o Return the self-timer lever to "L",
o Press the battery check button or set the dial
at "B" and take your finger off the button.
(4) Self-timer operation indicator
A red LED beside the shutter button keeps flashing
while the self-timer is in ' operation. When the self-
timer lever ia set to "10", the flashing frequency is
2 Hz until two aeconds b efo r e shutter release and
increases to 8 Hz after that time. When the self-
timer lever i. aet to "2", the LED flashes at 8 Hz
frequency.
This flashing helps the user to know approximately
when the ahutter will be released.
(5) Self-timer operation with the shutter button at "B"
If the self-timer is started w ith the ahutter speed
at "B", the camera will st op functioning the moment
your finger is taken off the shutter button. This
means that when the self-timer is in operation, it
will be cancelled. Since the self-timer will not
operate proper l y without a locking cable release when
the shutter speed is set at "B", Canon has employed
a safety device like that. (By using a locking cable
release, the self-timer can be used at RB" .. Of course,
manual exposure calculation is necessary).

3.9 Loading the Film
(1) Back cover
To open the back cover, pull up the film rewind
crank. The camera's back cov er has a memo holder.
The back cover is interchangeable with the AE-l's
back cover, and Data Back A.
(2) Film loading
o Easy film loading with multi-slot take-up spool.
o The film is wound around the spool in the counter-
clockwise way.
(This is the same with the AE-l.)
(3) Film advance lever
o Single stroke with 1200 throw and 300 stand-off.
The film can also be wound with several short-
strokes.
o When the shutter is open, the film cannot be
advanced.
o The film can be wound wit h the shutter button
held in the depressed position. (These are the
same with the AE-l . )
(4) Frame
counter
Additive type. Automatically resets when the back
cover is opened. While rewinding film, it counts
backword. The frame counter does not advance during
multiple exposures.
5·2.4·· ··· 18·20·22·····34·36·38
0, 20, and 36 are orange, other numbers are white.
(5) Film rewinding
Performed by using the rewind crank on the top. When
the rewind button is pressed, it will be held in the
depressed position and disengages . the film from the
film tr a nsport sproc ket . T he rewind button automati-
cally resets by winding the fil m advance lever.
11

3.10 Multiple Exposures
(1) Operation
1) Press the multiple exposure lever towards the
film advance lever.
2) Operate the film advance lever, and the film
remains stationary and holds its exact position
while cocking the shutter and charging the AE
mechanism.
3) By operating the film advance lever, the multiple
exposure lever automat i cally returns to its
original position.
4) . The frame counter does not advance.
5) Ratchet winding used for multiple exposures.
(2) Application
1) To perform multiple exposure
2) To reset the mechanism when the error mark
"EEEE EE" is dis playe d in the viewfinder. The
camera will not f uncti on even if the shutter
button is pressed until the multiple exposure
lever is pressed.
(3) Other points in multiple exposures
1) Multiple exposures cannot be performed when the
Motor Dr ive MA or Po we r Winder A is in use on
the A-l.
2) Once the multiple exposure lever is set, the
camera will not function even if the shutter
button is pressed.
When the viewfinder is showing the error mark,
set the multiple expo s ure lever to put out the
flashing for normal Viewfinder display.
3.11 Camera Body
12
(1) Main Body.
(2)
Upper cover and
apron:
Aluminum die-cast body
Made of multi-layered metal plated
plastic

(3) Tripod socket:
(4) Action grip:
3.12 Dimensions and Weight
Screw-in type (CU 1/4) in the
center of the bottom
A large detachable type finger grip
is available
141 (W) x 91.5 (H) x 47.5 (D) mm
-=~~:rJ .. . '.D
I I
141
144 (including
hinges)
3.13 Related Accessories
(1) Standard"
- Accessory shoe cover
- Silver oxide battery
- Body cap R-F
- Eyecup 4S
620g (body only, including a
battery)
- Neckstrap (with a shoulder pad)
- Adapter for tripod
- Action grip
- Semi Hard Case S or L
(2) Main system accessories
- FD lenses
- Motor Drive MA (new)
- Power Winder A
- Speedlite 199A (new)
- Speedl1 te 155A
- Data Back A
13
,

4. Main Features
4.1 Finder
14
Reversing the current trend to more and more complicated
viewfinders with exposure information encroaching into the
field of view from every direction, the A-I viewfinder
shows the field of view alone in a dark field. When the
shutter button is pressed, the exposure information appears
in neat digital form of red seven segment LEDs below the
field of view if you wish to view it.
(1) Viewfinder Optical Design
A special optical plastic is used to make the prism
which reflects the image of the LED's thru the penta-
prism into the eyepiece. The LED's are located below
the prism, well away from the SPC so they do not
affect its reading.
Fresnel lens
SPC
Image guide prism
Fig. I Viewfinder Optics

1,.00 I.' M
Fig. 2 Field of Vision for the
Viewfinder
(2) Replacement of Focusing Screen
The standard outfit for the A-l is the split-image
microprism screen type . In addition, there are 6
types and the replacement of screen is possible at
the authorized service facilities.
(3) Preventing the Ingress of Dust
Finder unit consists of a focusing screen, condenser
lens, pentaprism, eyepiece lens, LED for display of
information and light guide prism. As in the case of
the AE-l, they are tig h tly sealed against the ingress
of dust.
4.2 Viewf i nder Information (character display viewfinder)
The viewfinder information bf the A-l includes the AE mode
selected, pre-programmed and compated exposure values, warn-
ings of incorrect exposures and improper settings for AE
photography. These pieces of viewfinder information play
a vital role in taking pictures.
This viewfinder is one of the main features of the A-l. We
call it a character display viewfinder.
(1) Display position and method
Viewfinder information is displayed in the red LED's
below the viewing area.
The display is designed so it is turned off when the
viewfinder information is not necessary such as when
15

16
shutter is functioning or the self-timer is in opera-
tion. Th is saves the battery.
Some people find it easier to ~oncentrate on composing
the picture without the viewfinder information. A
sw i tch is provided so the display cam be turned off.
(2) Contents of the viewf i nder display
1) Information format
The following display format is used in the view-
finder:
BBBBBB M
2) Information displayed
(a) Shutter speed
1/2 step increments from 1/1000 sec. to 30
sec. in 1/2 step increments, plus "8",
maximum four digits. ("BOO is displayed as
buLb orbu·)
(b) Aperture
f/l.2 to f/32 in 1/2 step increments,
two-digit display.
(c) The "F" letter dis p lay lights up when the
f l ash unit (155A or 199A) is used and ready.
(d) The "MOO letter lights to warn when the camera
is not set for AE operation.
(e) When the tension of the aperture signal coupl·
ing lever of the c ame ra is cancelled, the
error mark lights up (six LEDs light up as
EEEE EE).
If, after stopping down the lens by lens
disengaging it from the ~A" mark, the stop-
down lever is rel ea se d and the lens aperture
ring returned direct ly to the "A" mark, the
error mark will ligh t up.
If this happens, the s hutter button cannot be
released and no furt he r pictures can be taken
. ;
Under the same situation for the AE-l it is
necessary to turn th e aperture ring to the
-.

*.
•
maxi m um aperture before resetting it to the
"A" mark.
The information (a), (b), (c), and (e) is display-
ed in seven segment LED's and (d) in a five-digital-
segment LEO*.
Numerals shown in 1/2 step increments are not
always strictly exact ones and may be rounded off
to familiar ones.
(Example)
An intermediate value between f/2 and f/2.8 is
f/2.38 but it is displayed as f/2.5 (differ-
ence is 0.15 f/stops).
o Shutter speeds longer than 1 sec. are displayed
with the second(") mark.
(Example)
1/15 sec. is displayed as
15 sec. is displayed as
o Exposure is, as a matter of fact, controlled in
1/8 step increments. However, it would be trouble-
some to have these values display in the viewfinder
as they would change so quickly depending on light-
ing conditions. Because it would be hardly possible
to see a continuously changing shutter speed and
aperture readout which are unfamiliar to users,
we have done much testings about viewfinder infor-
mation. After considering the physiological
characteristics of human eyes, we have arrived
at the conclusion that the signals of exposure
should be transmitted to the display in 1/2 step
increments.
This is why the A-l's viewfinder displays shutter
speed and aperture values in 1/2 step increments
as indicated below.
The M has five segments itself.
the aperture is electrically one
The decimal pOint in
segment of the M digit.

18
Tv Indication 180 - 10- 250 ... 350 ,,"SOD 00-150
250 500
5.6
a
Av Indication
1./ .5 10- 56 10- 6.1
.... 80 10- 9.S
Fig. 3 Display Indication in 1/2 Step
Incrementa

100 0
'1 5 0
500
350
250
I 8· 0
I 2 5
9 0
5 0
4 5
3 0
2 0
I 5
I 0
B
5
4
3
2
o " '7
I "
I " 5
2 /I
3 /I
4 /I
5 /I
8 /I
I 0 "
I 5 /I
2 a "
30"
b u L b
F
b u F
E E E E
3 2
2 IJ
2 2
I 9
I 5
I 3
I I
9.5
8.0
5.'7
5.5
4.5
4.0
3.5
2.8
2.5
2.0
I • 8
I • 4
I . 2
E E M
. 4 Numerals and Characters to be Displayed
19