Some Auto-Focus History
Flynn Marr 17 September 2024
It was Minolta who came up with the first truly practical AE-AF motorized 35mm system camera: the Minolta Maxxum 7000 introduced in February of 1985.
Researching for my page on the Canon AL-1 I wrote my last post here about Contrast Detection Auto-Focus. Now I have been researching for a page on the Canon T80 which was Canon’s first real auto-focus SLR and I fell into the rabbit hole of auto-focus history. Rather than let this historical detail sit undiscovered in my notebooks, I shall transcribe what I found and write it here. It is a summary only of a very complex evolution but it will add perspective and help place some of Canon’s cameras in their proper place in the evolution of this last great technical photographic challenge before the arrival of the modern DSLR’s.
The 1970’s and 80’s were a creative time in the camera industry. Competition was fierce between camera companies to come up with technologies that would drive sales. Auto Exposure (AE) in SLR’s was the goal in the 1970’s and it was realized beautifully in the AE-1 of 1976. In the 1980’s the challenge was Auto Focus (AF), the last great advancement required before the advent of the modern automatic camera.
The problems that the camera companies were facing were several. Auto-focus, even more than Auto Exposure, involved computers, electrical motors, solid state light sensing devices, and signal amplifiers all of which were new and foreign to traditional photography. It took time and trial and error to assemble the research teams, train the technicians in these new arts, and to work out the best way to accomplish automatic focus in 35mm cameras.
The necessary theory was well known and was never the problem. There were patents for self focusing cameras filed in the USA as early as the 1930’s and continuing into the 1940’s and 1950’s. The problem was learning how to implement it. Not only did the camera designers have to learn how to do it but they also had to figure out how to fit the necessary devices into the already cramped bodies of 35mm cameras.
In the 1960’s and 70’s solid state electrical devices were just coming into their own and they were bulky, at least by today’s standards. And many devices we now rely on were newly discovered or yet to be so. So not only did the engineers have to learn how to design these new devices but they had to wait for the creation and miniaturization of the electrical components they required. It was not possible to design an SLR that was self focusing before the mid-1980’s. In 1965 a single transistor was so large that they would have had a problem fitting it into an SLR body and their designs required dozens if not hundreds of them and their associated resistors and capacitors.
All of the camera companies faced these same problems and were waiting for the same components. For this reason there were many early attempts from several companies all happening in a short period of time.
The Leitz company began working on a self focusing technology in the
early 1960’s and actually got so far as producing a prototype camera that relied on Contrast Detection to focus the lens. Contrast Detection works based on the idea that the image will have the highest contrast when the image is in focus. Ultimately Leitz decided not to proceed with a production camera and they sold their research to Minolta in Japan.
Canon understood the importance of developing a practical auto-focus camera very early on and they actually displayed a prototype self-focusing camera at the Photokina show in Cologne, Germany, in March of 1963. Bob Shell tells us that a second prototype was shown at the show the following year and in 1966 a third prototype was shown but for a 126 film camera and not 35mm. These cameras were not practical and needed bright light for the focus to work consistently.
The Konica C35 was the first mass produced auto-focus camera to come to market in November of 1977. It used an active infra red beam emitted from the camera and reflected back from the subject on which the camera could triangulate.
The second camera to incorporate auto-focus was the Polaroid SX-70 Sonar which was actually a family of cameras first introduced in 1972. These were a single lens reflex design although obviously not a 35mm cameras. In 1976 Polaroid added the Sonar AutoFocus unit to the SX-70 camera.
Canon Sure Shot
Canon’s first Auto Focus camera, the original Sure Shot also called the AF35M in Europe or Autoboy in Japan, came out in November of 1979. It too was a “Point and Shoot” camera and Canon called it “the world’s first Lens-Shutter 35mm autofocus camera”. I am not sure that was true but if you add that it had powered film wind and rewind then it was accurate. The Konica C35 had manual film advance and rewind. The Sure Shot was an active auto focus system that used a transmitted IR beam that reflected off the subject and allowed the camera to triangulate on the return signal.
FD 35-70mm f/4 AF
Canon continued to investigate self focusing technology and in May of 1981 released the FD 35-70mm f/4 AF lens. This interesting lens was a self contained focusing unit that could be mounted on any camera with an FD lens mount, or even an FL mount. This lens had all of the necessary electronics, motors and batteries in the lens and did not require any input from the camera body. Although it mounted on true 35mm SLR’s it was not a true self focusing camera.
Canon Super Sure Shot
We should point out the two general types of Auto-Focus systems, the “Active and the “Passive”. In an active system, the camera sends out a signal which reflects off of the subject and back to the camera. In a passive system the camera does not send out any signal but analyses some aspect of the light from the subject to determine how to focus the lens. Some modern cameras such as some EOS Rebel cameras use both systems depending on the available light level.
It was Konica that that introduced the first mass produced self focusing camera with its Model C35 AF in November of 1977. It was a “Point and Shoot” style camera and certainly not an SLR. It was an active system which relied on an IR beam emitted by the camera reflecting off the subject on which the camera could then triangulate.
Polaroid SX-70 Sonar
The first Single Lens Reflex auto focus camera was actually the foldable Polaroid SX-70 Sonar camera released in 1978. The SX-70 was actually a series of folding SLR cameras first introduced in 1972. Of course this was not a 35mm camera and not an SLR in the sense we are using the term.
Polaroid added the Sonar AutoFocus unit to the SX-70 in 1976. This camera also relied on an active focusing scheme but instead of an IR beam it emitted an ultra sonic beam and used sound projected outward from the camera and focus depended on the time it took to detect the return reflections or echos. Light is too fast but this system can work with sound. Bats have used sonar for millenia to hunt for their diner.
The first of the Sure Shot line introduced in November of 1979 was an auto focus camera which also had powered film advance and rewind.
The FDn 35-70mm f/4 AF was a fully self contained auto focus lens that could fit on any camera with an FD lens mount.
In July of 1981 Canon released its second auto focus camera, the AF35ML. It was another point and shoot camera much like the earlier AF35M. However, unlike its precursor, it had a passive focus system that did not rely on an IR beam emitted by the camera. But these were not SLR cameras and certainly nothing that professional photographers could use.
The problem to be faced with auto focus for the SLR was the lens which had to be interchangeable and yet self focusing. How was this lens to be powered? Where would the motor to be placed? How would focus be achieved? The initial attempts to solve these issues were not promising.
The Pentax ME-F introduced in November of 1981 was a modification of the Pentax ME Super. It was the first true autofocus interchangeable lens SLR to come to market. It relied on contrast detection for the auto focus. The lens mount was a modification of the Pentax K mount and it would accept the Pentax line of lenses plus the special 35-70mm f/2.8 AF zoom which could focus automatically. With manual lenses the camera body would indicate which way to turn the lens for proper focus like the Canon AL-1 did.
For reliable operation these early auto focus lenses required bright light, good contrast and subjects that were not moving. As a result these early attempts were not commercially successful. The ME F was dropped from the Pentax line in in 1984.
Also in 1981 Chinon released their Chinon CE-5 which was based on the Pentax K lens mount as well. The camera could mount most Pentax K mount lenses but there were two auto focus lenses made for it, the standard 50mm lens and a 35-70mm zoom lens. These lenses were large and ugly and they never received much commercial attention.
The Canon AL-1 used Canon’s standard FD and FDn lenses but the camera body sensed when the lens was in focus and LED’s in the viewfinder assisted the user to find perfect focus.
The Pentax ME-F had a Pentax K lens mount with added electrical contacts. The camera would mount the auto-focus lens designed for it or other K mount lenses. But the auto-focus lens was an awkward design and never proved popular.
The Chinon self focusing lenses were not practical and received very little commercial notice but the camera could use other K mount lenses.
Canon AL-1
Canon’s first SLR to have self focusing capability, well almost, was the AL-1 introduced in March of 1982. This camera had an FD lens mount and the camera body was able to find the point of focus by sensing the contrast in the image. However, there was no ability to move the lens. The body indicated to the user which way to rotate the lens barrel and when best focus was obtained. But user had to provide the power to actually focus the lens this way or that.
The Olympus self focusing lenses were obviously an interim solution that still required a lot of work!
In April of 1983 Canon released the New Sure Shot (also the AF35M II or Autoboy II) which was another auto-focus point and shoot in the Sure Shot line.
The next serious entry was the Olympus OM-30 ( aka OM-F in the US) which was introduced in 1983 . It was issued with a Zuiko 35–70mm AF zoom autofocus lens.
Notice that the auto focus lenses we are looking all seem to be normal lenses with large add on compartments for motors, gears and batteries. The manufacturers were still struggling to figure out the best way incorporate all of the reqired machinery into a detachable lens. None of these solutions seem very satisying so far.
So where was Nikon in the auto focus sweepstakes? As early as 1971 they had showcased a prototype 80mm f/4.5 AF lens but it was not until 1983 that they actually offered self focusing cameras for sale.
The Nikon L35AF was a well received compact automatic camera that still gets good reviews from film shooters of today.
The F3AF was essentialy an F3 professional camera adapted to two specialty autofocus lenses. However, it was and “F” series Nikon and could accept all of the F Series accessories such as non-AF viewfinders, winders, focusing screens, and lenses.
displayed in the viewfinder. And there were four user interchangeable focus screens. The camera was very popular with these features. And later in 1985 Minolta released the Maxxum 9000 aimed at the more professional user.
The Maxxum proved so popular that it propelled Minolta to the top tier among camera makers and it took the EISA European Camera of the Year for 1985.
The first Nikon Self-Focusing camera was a compact style point and shoot, the L35AF. This camera had an excellent 5 element f/2.8 lens and the auto focus was reasonably accurate. Released in 1983 this camera is still receiving positive reviews from film shooters some of whom are still using it.
The other Nikon offering of that year was the Nikon F3AF which was a professional grade 35mm SLR that could be used with either of two auto focus lenses offered by Nikon: the AF 80mm f/2.8 and the AF 200mm f/3.5 ED-F. Released in April of 1983.
This camera retained the Nikon F camera mount and was compatible with other lenses of the same mount. Not only that but the camera could use other Nikon viewfinder prism assemblies as well Nikon’s wide range of accessories. It could function just as well as a manual camera with the added advantage that the focus sensing circuits would assist with focus just as the Canon AL-1 would do.
This was revolutionary because the camera was of exceptional quality, the lens were Nikon famous, and they appeared like normal Nikkor lenses. Additional AF lenses were promised but none appeared and the camera was eventually overtaken by developments in the camera industry.
By 1984 a camera user could buy a fully automatic compact camera and expect reasonably good performance. The picture was not quite as rosey if he/she wanted a self focusing SLR. The only available camera that was not an obvious dead end would have been the F3AF but that was an expensive proposition and for the average user it was probably too much camera. The AF SLR selection was not great and consumers were staying with manual focus cameras. But that was about to change.
Canon introduced the T80 in April of 1985 and it marked the company’s first foray into a complete auto focusing SLR. It was aimed at the entry level user and all its features were automatic. Unfortunately for Canon, Minolta released the Maxxum 7000 in February of 1985, three months earlier, and it was clearly aimed at more advanced amateurs. It was really intended as a more serious camera for the serious user. And it overshadowed the T80 commercially.
The Maxxum 7000 was the first production SLR camera to come to market to feature both integrated AF and internal power advance and rewind of the film. The AF functions and the motors to focus the lens were located in the body and metering modes included Program, Av and Tv as well as manual operation. Focusing was via a passive phase detection circuitry located in the camera body. Shutter and aperture settings were
The Minolta Maxxum 7000 was introduced in February 1985 to great acclaim and over the next several years proved a great commercial success. Later in that year the Maxxum 9000 was released aimed at professional users.
The Canon T80 had three auto-focus lenses but the FD-FA lens mount would accept Fd and FDn lenses that had to be manually focused.
The Canon T80
A few months after the introduction of the Maxxum 7000 Canon came out with the T80, their first venture into a fully automatic 35mm SLR. This camera was aimed at a more entry level user than the Minolta offering. It had an FD lens mount and so it was possible to use other FD and FDn lenses. Only three auto focus lenses were made for it and it had problems focusing in low light. But it was inovative and an interesting camera to use. Unfortunately, this camera fell in with the earlier AF attempts and was not a totally practical purchase and as a result was not a great commercial success. But we will deal with that on another page.
And in Conclusion…..
After the T80 Canon had two further manual focus cameras and then in 1986 they introduced the Maxxum killer: the EOS 650. And from then on auto focus was a thing in pretty much all new SLR cameras.
And here endeth the Auto Focus lesson. Sorry if it was a little over long and yet skimpy on detail. We have looked at all of the main cameras on the path to AF SLR’s and now that you have the names you can dig into the Internet and find all kinds of information about them. Each one is interesting in its own right and I wish we had the time to do that here. But this web site is about Canon cameras and I think we should stick to them.
The EOS 650 was the first of the EF Series and the beginning of auto-focus as a standard feature on Canon cameras.
NOTE ABOUT THE IMAGES: I do not have the non-Canon (is that a word?) cameras in my collection to photograph for this post. I have therefore scrounged images from the Internet to illustrate my writing. If I have used one of your images let me know and I will either give credit for it or remove it as you wish. And thank-you for your forbearance.
This website is the work of R. Flynn Marr who is solely responsible for its contents which are subject to his claim of copyright. User Manuals, Brochures and Advertising Materials of Canon and other manufacturers available on this site are subject to the copyright claims and are the property of Canon and other manufacturers and they are offered here for personal use only.