SR-3
SR-3
(1960) The SR-2 was a very advanced camera for
the time, but it had two major drawbacks. First, it was expensive and
second, it lacked a built-in meter. These were enormous drawbacks and
kept Minolta SLR sales down. The year before, 1959, Canon had introduced
its Canonflex SLR camera which had a clip-on selenium meter that was coupled
to the shutter speed dial, and in 1960, Nikon unveiled the Nikkorex 35 SLR
with a built-in selenium meter! Minolta addressed the first issue by
producing the SR-1, and it addressed the second with
the SR-3.
A separate, hand-held meter was necessary in order to use the meterless
SR-2. This made the SR-2 less
desirable, especially when compared to other, contemporary SLR cameras that
had a built-in meter, such as the Contaflex Super and the Voigtlander Bessamatic.
Minolta had to scramble so as not to lose the competitive edge that
it had gained in the market with the introduction of the
SR-2 in 1958. The SR-3 was an improved model
of the SR-2 in that it added a provision for a clip-on,
selenium meter -- the SR Meter (it could also accept the later SR Meter
II). Without the meter attached, the camera operated just like
the SR-2. But with the meter connected (it sat
right on top of the shutter speed dial), the camera provided what Minolta
called "semi-automatic" exposure control. It was only automatic in
the sense that as the needles on the top of the meter were matched-up, the
shutter speed was changed -- "automatically". Yet, this approach was
very advanced in 1960 and made exposure much more convenient. Most
of us today would refer to this as "metered-manual" exposure control.
With the SR-3, you had the advantage of being able to buy a camera and get
a meter later. Still, its meter lacked the compact, built-in nature
of other camera-meter combinations, like the Contaflex Super and the Voigtlander
Bessamatic. With these cameras, the meter was integrated into the camera
-- something that Minolta would accomplish two years later with the
SR-7.
The SR-3 was designed to be used with a special, clip-on, SR meter. The
shutter speed dial has a small tab that connects to the bottom of the meter.
First, dial in the film speed on the meter, and then select a shutter
speed. As you select a shutter speed on the meter, the same speed is
set on the camera. Next, point the meter toward the scene and read
the correct f-stop on the top of the meter. Set that f-stop on the
lens, and take the picture. (Alternately, the f-stop could be selected
first and then the shutter speed dial turned until the needle in the meter
readout points to the same f-stop.) This process was so convenient
that they actually called it "semi-automatic" exposure control back in those
days! It was a process that Minolta had developed on the
Super A camera of 1957 -- the first Japanese camera
to offer this feature. Minolta should have used this feature on the
SR-2 of 1958, but instead, Canon stole the idea and
used it on the Canonflex of 1959 -- grabbing the thunder that rightfully
belonged to Minolta.
The SR-3 had other differences over the SR-2, besides
the clip-on meter option. The shutter on the SR-3 was more quiet, although
it's still loud by present-day standards. Also, the viewing screen
in the SR-3 added a split-image rangefinder in the middle of the microprism
circle -- a big deal at the time. From now on, all of Minolta's
top-of-the-line cameras would have this type of screen. In addition,
the SR-3 had equidistant shutter speeds on the shutter dial. On the
SR-2, the faster the speed, the closer it was the the
next speed on the dial. This gets pretty awkward at the higher speeds,
and can cause errors, especially in dim light.
Last, but not least, Minolta modified their viewfinder mount on the SR-3.
On their previous cameras, viewfinder accessories were screwed into
place on the round viewfinder. On the SR-3, the viewfinder is still
round, but the accessories are attached with a new bayonet fitting. The
new accessories will not fit onto the older cameras, just as the old accessories
will not fit onto the newer cameras. The names of the accessories were
changed as well. For example, the screw-in Angle Finder SR which fit
the SR-2 became the bayonet Angle Finder SR-2 which fit the SR-3. This,
of course, leads to some confusion. The Angle Finder SR-2 has nothing
to do with the SR-2 camera; it was just the second style of anglefinders.
There were actually two versions of the SR-3 although the bodies of the camera
look identical and these model numbers are not marked on the bodies:
SR-3 (model a) -- (1960)
On the original model of the SR-3, the lens diaphragm action was
"semi-automatic". In other words, with automatic diaphragm lenses,
while the lens stayed at full aperture until the moment of exposure, it did
not automatically return to full aperture after the exposure. In order to
regain the full aperture setting, it was necessary to advance the film, which
cocked the shutter and reset the diaphragm to the open position.
SR-3 (model b) -- (1961)

On this version of the SR-3, the diaphragm retained the open position even
after the shutter is released. Minolta made a similar change to it's
SR-1 camera at the same time. This automatic diaphragm
was an advanced, convenience feature, but it had one drawback. When
someone wanted to check the depth-of-field, they could no longer do this
in the viewfinder since the lens never "stopped-down". Minolta solved
this problem by adding a DOF (depth-of-field) lever to their lenses. This
was, in fact, a major change. The problem for Minolta was that their
lenses already had enough levers. First, there is the f-stop ring and
the focusing ring. In addition, all their lenses had an f-stop lock
tab to help prevent accidental movement of the f-stop ring. With the
addition of a DOF lever, the lenses would become unnecessarily complicated.
To resolve the issue, Minolta opted -- wisely -- to remove the f-stop
lock tab and replace it with the DOF lever. This required no change
in the cameras, but confused some consumers since it's difficult to tell
the difference between an f-stop lock button and a DOF button. On some lenses,
they looked nearly identical. Oh well, it was a step in the right
direction. It was only a change made on the Rokkor lenses of the time
and Minolta added stop-down "clicks" to each setting on the f-stop rings
on these new lenses to indicate change in the diaphragm and prevent accidental
movement. So you will see the same Rokkor lens in two different styles
(see the MINMAN SLR lens list for complete details
-- the most complete Minolta lens list in the world!). But in order for this
to happen a change had to be made to the
Auto-Rokkor
lenses.
Initially, the
Auto-Rokkors were
designed for the
SR-2 and early
SR-1 cameras that
had semi-automatic aperture function. With this feature, the aperture
on the lens was cocked when the film was advanced. A pin in the camera
kept the lens at full aperture. When the shutter was released, the
pin in the camera released the pin in the lens, and the lens was stopped
down. Resetting the lens required the slow pressure of the film advance.
But this changed when Minolta introduced the
SR-3 and
SR-1 (model c)
which were designed for fully-automatic aperture operation. These camera
automatically reset the lens to full aperture immediately after each exposure
-- without advancing the film -- and the old mechanisms proved inadequate
to the task. An important change had to be made to the Auto-Rokkor
lenses at this time. To allow the new cameras to instantly re-open
the aperture in the lens after the exposure, it was necessary for Minolta
to modify the aperture linkage in the original Auto-Rokkor lenses. (The Rokkor
lenses didn't require any change since they lacked the aperture linkage.)
Specifically, the original Auto-Rokkor lenses have their aperture linkage
on a rotating, external plate on the back of the lens. This approach
proved inadequate to handle the speed of a fully-automatic aperture, and
Minolta modified the mechanism to an internal, lateral-operating pin. This
approach had additional advantages other than just a fully-automatic aperture.
On the original Auto-Rokkor lenses (those with the rotating external plate),
the aperture linkage moved up and down as it rotated. This required
a fairly tall lever inside the camera body, to make sure that the two would
always engage -- as the pin in the lens moved up and down, and the pin in
the camera moved left and right. It also required a fair amount of
pressure from the lever in the camera to open the lens up. With the
new, lateral-moving aperture pin in the lens, the lever in the camera could
be shorter and, as a result, the mirror in the camera could be made bigger.
This helped eliminate the image cut-off that was seen with long telephoto
lenses. (Minolta called it an over-sized mirror and it was used in
all of their subsequent 35mm SLR cameras.) The drawback is that the
original Auto-Rokkor lenses will not operate at all f-stops on later cameras.
You'll be able to select any f-stop on the lens, but when the older
lens stops down, the aperture will stop at around f8. For example,
let's say you dial in f16 on the aperture ring. When the exposure is
taken, the lens will only stop down to f8 and the picture will be over-exposed
by two f-stops. These older lenses were designed for cameras with tall
aperture pins and when used on newer cameras, at higher apertures, the tab
in the lens is not fully released. While this will not cause damage
to the lens or camera, it prevents the smallest f-stops settings from being
used.
The SR-3 was a stop-gap camera. It was an attempt by Minolta to keep
up with other manufacturers that were offering cameras with built-in metering.
Minolta was caught with its pants down. To deal with the issue,
in the next year, 1961, Minolta would market the ER
SLR. It was an SLR with a built in meter. And although it lacked
interchangeable lenses, the ER featured automatic exposure -- a remarkable
achievement in SLR cameras. And in the next year, 1962, Minolta
marketed the amazing SR-7, the first Minolta SLR with
interchangeable lenses AND and built-in meter -- a CDS meter to boot! It
was the first Japanese SLR to accomplish this feat. Minolta was back
in business, and the SR-3 was lovingly placed into the history books.
For a comparative look at the major features of the SR-3 models, check out
MINMAN's SLR table
-- the world's most complete!
CAMERA SPECIFICATIONS
| Camera |
SR-3 |
SR-3 |
| Model |
a |
b |
| Years made |
1960-1961 |
1961-1962 |
| Type |
Mechanical 35mm SLR |
Mechanical 35mm SLR |
| Shutter |
Fully mechanical, horizontal, cloth focal plane shutter |
Fully mechanical, horizontal, cloth focal plane shutter |
| Metering |
None |
None |
| Meter sensitivity |
-- |
-- |
| Exposure modes |
Manual |
Manual |
Automatic exposure
adjustment |
-- |
-- |
| Viewfinder |
Fixed eye-level pentaprism |
Fixed eye-level pentaprism |
| Focusing screen |
Fresnel-field screen with a micro-prism center |
Fresnel-field screen with a micro-prism center |
| Lens mount |
Minolta SLR bayonet |
Minolta SLR bayonet |
| Lenses |
Optimum: early Auto
Rokkor
Usable: later Auto Rokkor, Rokkor, MC Rokkor, MC Rokkor-X, MC Celtic, MD
Rokkor, MD Celtic, MD Minolta |
Optimum: later
Auto Rokkor
Usable: early Auto Rokkor, Rokkor, MC Rokkor, MC Rokkor-X, MC Celtic,
MD Rokkor, MD Celtic, MD Minolta |
| Mirror |
Instant return mirror |
Instant return mirror |
| Film speeds |
-- |
-- |
| Shutter speeds |
Mechanical: 1 - 1,000; B
Manual: 1 - 1,000; B |
Mechanical: 1 - 1,000; B
Manual: 1 - 1,000; B |
| Flash synch |
X: B; 1 - 1/60
FP: B; 1 - 1/15
M: B; 1 - 1/15
MF: B; 1 - 1/15 |
X: B; 1 - 1/60
FP: B; 1 - 1/15
M: B; 1 - 1/15
MF: B; 1 - 1/15 |
| Flash connection |
Clip-on, cold shoe
X and FP PC contacts |
Clip-on, cold shoe
X and FP PC contacts |
| Film counter |
Automatically resetting type counting upward |
Automatically resetting type counting upward |
| Battery |
-- |
-- |
| DOF/Stop-down button |
No |
No |
| Film Back |
Non-interchangeable |
Non-interchangeable |
| Multiple exposures |
No |
No |
| Film advance |
Lever type |
Lever type |
| Self-timer |
Mechanical, overrideable, non-cancellable, adjustable from 4 to 10 seconds |
Mechanical, overrideable, non-cancellable, adjustable from 4 to 10 seconds |
| Film reminder |
No |
No |
| Other |
Cable release connection, tripod socket |
Cable release connection, tripod socket |
| Body size |
2 x 3 1/2 x 5 3/4 inches |
2 x 3 1/2 x 5 3/4 inches |
| Body weight |
One pound two ounces |
One pound two ounces |
RETURN TO THE MANUAL
MINOLTA HOME PAGE
We didin't want to do this, but since other websites have been stealing our
stuff, we have no alternative but to state:
COPYRIGHT@1995,1996,1997,1998,1999,2000,2001,2002,2003,2004 by Joe McGloin.
All Rights Reserved.
|