AUTO ROKKOR LENSES
The Rokkor and Auto-Rokkor lines of lenses were
the first offering of lenses from Minolta for their SLR cameras. The
Auto-Rokkors were the deluxe line of lenses, while the
Rokkor line was the simpler line of Minolta's lenses
The SLR cameras of the past were much simpler creatures than those we know
today. In addition, mechanically, lenses were much simpler and not coupled
to the camera in any way. Today, we call these lenses, "manual
lenses". Prior to 1958, nearly all SLR cameras lacked built-in meters,
and all of the lenses for SLR cameras had manual diaphragms. This meant
that taking a picture was a much more arduous task than it is today.
Whenever the lens was stopped-down, the camera viewfinder got dark. Using small f-stops was a real challenge as the viewfinder quickly became useless. With these cameras and lenses, you first composed and focused the picture with the lens set at the widest and brightest f-stop. Next, you removed the camera from your eye to take a meter reading -- a separate hand-held meter was standard in those days. The meter told you where to set the f-stop on the lens and the shutter speed on the camera. Next, you made the necessary adjustments to the camera and lens. Finally, you raised the camera back to your eye, re-focused the picture and re-composed the scene through a darkened viewfinder, before taking the exposure. The viewfinder was darkened because the aperture of the lens had been stopped down. This process was quite awkward and one of the reasons why the SLR design wasn't immediately popular when it was introduced. Other camera designs, such as rangefinder and TLR cameras, didn't have this problem because you didn't look "through the lens" and were much less expensive. These alternatives to the SLR were very popular and, as a result, SLR sales were depressed substantially.
Manufacturers "solved" the problem in one of two ways -- each more awkward than the other. One approach, sometimes referred to as "semi-automatic", required the SLR photographer to cock the lens -- moving a lever on the side of the lens to set it at the largest f-stop -- after cocking the shutter. This kept the lens open to the maximum aperture until the picture was taken. A small lever in the camera released the lens just before the exposure was taken. But separately cocking the shutter and the lens was time-consuming. The other approach is referred to as "pre-set". These lenses have the standard aperture ring, but add a "pre-set" ring right next to it. On the aperture ring, you dial in the f-stop you want to use for the exposure, but leave the pre-set ring at full aperture. This set-up let's you compose and focus with the lens wide-open. Then, just before taking the picture, the pre-set ring is turned -- which stops the lens down. It's pretty awkward and prone to errors. First, fast, spontaneous pictures are impossible. And if you forget to turn the pre-set ring, the exposure is way off. Another problem with early SLR lenses was attaching and removing them from the camera. This was a rather awkward and time-consuming process -- and best accomplished with three hands.
By 1958 Minolta had figured out how to make an easy-to-use SLR, and they hit the ground running! Other manufacturers had to scramble to keep up. It's no secret that the Minolta SR-2 completely changed SLR photography, and made it the wave of the future. That's why it's listed in the book, "The Evolution of the Japanese Camera" (published by the International Museum of Photography at George Eastman House in Rochester, New York) as one of the most important cameras in photographic history. The SR-2 and the Auto-Rokkor lenses made awkward lenses and blacked-out viewfinders things of the past. All of a sudden SLR cameras were actually fun to use instead of being too technically challenging for most people to master.
Auto-Rokkor lenses changed all that by allowing the lens to remain at the maximum aperture until the very instant of exposure -- regardless of which f-stop was manually selected. With the Auto-Rokkor lenses, the camera body offered automatic control of the lens diaphragm. This means that the lens would remain at full aperture regardless of the f-stop selected without the need to "cock" the lens. If you dial in f8 (because you know this is the correct setting for the exposure) the aperture stays at the maximum f-stop until the shutter release is pressed. The camera stopped-down the lens to the chosen f-stop automatically at the instant of exposure, and the lens was "cocked" automatically when the film was advanced. It's no big deal today, but at the time it was a huge achievement. This made picture-taking easier because you no longer had to manually switch between the maximun f-stop and the pre-set-f-stop just before the exposure. You set the lens at the correct f-stop and the lens stayed wide open. When you pressed the shutter release, the lens stopped down automatically -- without a need to reset the diaphragm! Big news at the time.
In addition, the Auto-Rokkor lenses had a new, easy to use, bayonet lens mount. Instead of the awkward, time-consuming screw-mounts and breech-mounts used by other manufacturers, these lenses offered a quick, three-pronged, bayonet mount. This mount is so simple that it is easy to use with a single hand, and only requires a quick, 54 degree turn to lock the lens in place. Pre-setting anything on the lens or the camera was no longer needed -- well, at least as long as you owned a Minolta SLR camera! Changing lenses can be done in an instant, even in the dark, making spontaneous SLR photography a reality -- finally.
You can identify the Auto-Rokkor lenses by the front panel around the lens. The word "AUTO ROKKOR" is the main designation and it is marked in white. These lenses were designed for cameras that did not have meters or aperture displays in the viewfinder. As a result, the f-stop rings are not always placed directly next to the camera body which allows the f-stop to appear in the viewfinder display (if the camera is so equipped). These lenses evolved over time and you are likely to see the same lens with slightly different features. One feature that changed over time concerned the automatic diaphragm. Initially, the Auto-Rokkor 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.
A new feature was added to several of the later Auto-Rokkor lenses as a result
of their upgraded automatic operation. Since the newer SR-3 and later
cameras are designed for fully automatic aperture operation, a photographer
has no way of visually determining the actual f-stop setting by looking through
the viewfinder. A DOF button was added .
In other words, the aperture dial can be moved accidentally, but the photographer won't know because there is no obvious change in the brightness of the viewfinder. Minolta added an aperture lock on the f-stop ring to address this issue. In order to move the f-stop ring, this button must be pressed and held in place as you turn the aperture ring. Releasing the button locks the aperture in place.
Another change that occurred around the same time involved the LVS numbers that Minolta had put on the SR-2 and early SR-1 cameras. These numbers made exposure easier, but had to be inscribed on the shutter speed dial and on the lens aperture ring. On the shutter speed dial, the shutter speed numbers were on the top while the LVS numbers were on the side. This kept the numbers apart and avoided confusion. But on the aperture ring, the f-stop numbers and the LVS numbers were right next to each other. This created confusion for many budding photographers.
As you can see, the f-stop numbers on this sample lens run 1.8--2.8--4--5.6,
while the LVS numbers run 1.7--3--4--5. No wonder people got confused!
As a result, on the later Auto-Rokkor and Rokkor lenses, the LV numbers
were dropped, just as they were dropped from the shutter speed dials of the
later SR cameras. People were just going to have to deal with those
pesky f-stop numbers, like it or not.
These lenses were designed for cameras that did not have meters or aperture
displays in the viewfinder. As a result, the f-stop rings are not always
placed directly next to the camera body which allows the f-stop to appear
in the viewfinder display (if the camera is so equipped). You can identify
these lenses by the front panel around the lens (see above). The word
"AUTO" appears before the word "ROKKOR". The tab on the right is the
aperture lock.
These lenses were designed for cameras that lacked TTL meters, but they have the advantage of automatic diaphragms. With these, the aperture remains at the widest, and brightest setting -- until the moment of exposure. Then, for an instant, it stops down and -- an instant later-- it opens back up again. To use them with non-TTL cameras, the correct aperture and shutter speed are determined through the use of an external meter. These settings are then dialed into the camera, and the exposure is taken. The viewfinder will stay bright even when the lens is stopped down -- the aperture remains at full aperture until the moment of exposure. To use these lenses on later cameras with TTL meters, it is necessary to stop the lens down to the taking aperture to get a correct exposure reading. You just can't turn the aperture ring, because these are automatic lenses and the lens stays open. The camera has no way of knowing what f-stop has actually been set. To use on TTL cameras, first, focus and compose the shot. Next, select a shutter speed appropriate for the setting (or set the shutter speed dial to "AUTO"). Then, stop down the lens until the selected shutter speed is indicated. This is accomplished by pressing the DOF button on the camera (if it has one), or pressing the DOF button on the lens (if it has one), and then turning the f-stop ring. You can to use the Auto-Rookor lenses that lack DOF buttons on TTL cameras that lack a DOF button, but taking an exposure reading through the camera is not an option.
| FOCAL LENGTH | f-STOP RANGE | LENS INSCRIPTION | VIEW | DESIGN | FILTER THREAD | DIAPHRAGM | MC | MD | CLOSE FOCUS | SIZE | WEIGHT |
| 28mm | 3.5-16 | MINOLTA AUTO W. ROKKOR - SG 1:3.5 f=28mm | 75 | 7/7 | 67 | auto | no | no | 2' | 1.7"x2.5" | 8.5oz. |
| 35mm | 2.8-22 | MINOLTA AUTO W. ROKKOR - HG 1:2.8 f=35mm | 63 | 7/6 | 55 | auto | no | no | 1' | 1.7"x2.5" | 7.5oz. |
| 35mm | 2.8-22 | MINOLTA AUTO W. ROKKOR - HG 1:2.8 f=35mm | 63 | 7/6 | 55 | auto | no | no | 1' | 1.7"x2.5" | 7.5oz. |
| 35mm | 2.8-22 | MINOLTA AUTO W. ROKKOR - HG 1:2.8 f=35mm | 63 | 7/6 | 52 | auto | no | no | 1' | 1.7"x2.5" | 7.5oz |
| 45mm | 2.8-16 | MINOLTA AUTO ROKKOR - TD 1:2.8 f=45mm | 52 | 4/3 | 46 | auto | no | no | 3' | 0.6"x2.5" | 4.5oz. |
| 50-100mm | 3.5-22 | MINOLTA AUTO ZOOM ROKKOR 1:3.5 f=50-100mm | 47-24 | 15/9 | 77 | auto | no | no | 6.6' | 5.0"x3.2" | 1lb. 14oz. |
| 53mm | 2-16 | MINOLTA AUTO ROKKOR - PF 1:2 f=53mm | 45 | 6/5 | 52 | auto | no | no | 1.75' | ? | ? |
| 55mm | 2-16 | MINOLTA AUTO ROKKOR - PF 1:2 f=55mm | 43 | 6/5 | 52 | auto | no | no | 1.75' | 1.4"x2.4" | 7oz. |
| 55mm | 1.8-22 | MINOLTA AUTO ROKKOR - PF 1:1.8 f=55mm | 43 | 6/5 | 55 | auto | no | no | 1.2' | 1.4"x2.4" | 7oz. |
| 55mm | 1.8-22 | MINOLTA AUTO ROKKOR - PF 1:1.8 f=55mm | 43 | 6/5 | 52 | auto | no | no | 1.2' | 1.4"x2.4" | 7oz. |
| 58mm | 1.4-16 | MINOLTA AUTO ROKKOR - PF 1:1.4 f=58mm | 41 | 6/5 | 55 | auto | no | no | 2' | 1.6"x2.5" | 10oz. |
| 80-160mm | 3.5-22 | MINOLTA AUTO ZOOM ROKKOR 1:3.5 f=80-160mm | 30-15 | 15/10 | 77 | auto | no | no | 8' | 8.1"x3.4" | 4lb. |
| 100mm | 3.5-22 | MINOLTA AUTO TELE ROKKOR - QE 1:3.5 f=100mm | 24 | 5/4 | 55 | auto | no | no | 3.3' | 2.3"x2.5" | 8.5oz. |
| 100mm | 3.5-22 | MINOLTA AUTO TELE ROKKOR - QE 1:3.5 f=100mm | 24 | 5/4 | 52 | auto | no | no | 3.3' | 2.3"x2.5" | 8.5oz. |
| 100mm | 2-22 | MINOLTA AUTO TELE ROKKOR - PF 1:2 f=100mm | 24 | 6/5 | 62 | auto | no | no | 4' | 2.5"x2.6" | 150z. |
| 135mm | 2.8-22 | MINOLTA AUTO TELE ROKKOR - PF 1:2.8 f=135mm | 18 | 6/5 | 55 | semi-auto | no | no | 4' | 3.5"x2.5" | 1lb.3oz. |
| 135mm | 2.8-22 | MINOLTA AUTO TELE ROKKOR - PG 1:2.8 f=135mm | 18 | 7/5 | 55 | auto | no | no | 4' | ? | ? |
| 135mm | 2.8-22 | MINOLTA AUTO TELE ROKKOR - PF 1:2.8 f=135mm | 18 | 6/5 | 55 | auto | no | no | 4' | 3.5"x2.5" | 1lb.3oz. |
| 160-500mm | 8-22 | MINOLTA AUTO ZOOM ROKKOR 1:8 f=160-500mm | 15-5 | 16/11 | 77 | auto | no | no | 15' | 19.2"x3.4" | 6lb.1oz. |
| 200mm | 3.5-22 | MINOLTA AUTO TELE ROKKOR - QF 1:3.5 f=200mm | 12.5 | 6/4 | 67 | semi-auto | no | no | 8' | 5.5"x2.7" | 1lb.9oz. |
| 200mm | 3.5-22 | MINOLTA AUTO TELE ROKKOR - QF 1:3.5 f=200mm | 12.5 | 6/4 | 67 | auto | no | no | 8' | 5.5"x2.7" | 1lb.9oz. |
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