Who’s on first? With apologies to Abbott and Costello, when it comes to autofocus SLRs, it gets a little convoluted – for the company that was first, was also the company that was last.
Ernst Leitz Company (now known simply as Leica) had been quietly working on autofocus technology since the late 1950s, and received its first patent in 1960.
At the 1976 Photokina, it made the world’s first demonstration of a working autofocus system built into a Leicaflex SL2 body. At that stage, it was more of a focus confirmation system; the photographer focused manually, while watching two LEDs visible in the top of the finder. Both were lit when in perfect focus.
Leica showed improved versions at the 1978 Photokina and a further improved one at the Minneapolis convention of the Leica Historical Association of America (now known as the International Leica Society) in 1980. This iteration was built into a Leica R4-Mot body and had a servo-motor-driven Summilux lens, for true autofocus.
Despite its innovations, however, Leica never commercialized its Correfot system. It seems that Leica viewed itself as catering to skilled photographers who preferred manual focusing.
It believed that the early AF mechanisms compromised the "precise focusing" made possible by the renowned lens mounts (accurate to 1/100mm). And at that stage of autofocus development, it may have been right.
It’s not clear if Leitz sold or simply gave its patents to Minolta, under a technical cooperation agreement between the two firms that ran from 1972 to 1997. Either way, Leica did not bring out an autofocus SLR until its medium format S2 in 2008.
While the Konica C35 AF of 1977 was the very first AF camera (using patents licensed from Honeywell), it was Leica’s Correfot technology that enabled Minolta to build the first truly successful SLR with autofocus in 1985.
It was sold as the Minolta 7000 AF in most of the world, and as the Minolta Maxxum in North America.
Curiously, the Maxxum 7000 was considered "advanced" because it placed the focus motor in the camera body. Earlier efforts by Leica, Pentax and others all used motors built into or attached to the lenses, making them both heavy and bulky (for example, the Pentax ME-F of 1981).
Ironically, the best modern AF cameras now have the motors built into the lenses – but then these newer motors are much, much smaller.
The Maxxum 7000 was the first 35mm with automated film handling, as it loaded the film, sensed the film speed, advanced the film and then rewound it, all under motor control. Power was supplied by four AAA batteries housed in the large grip.
The Maxxum 7000 was also the first SLR to have the body made entirely of plastic. The 7000’s body is light, but doesn’t feel cheap – its tough, almost unbreakable ABS gives it the advantage of reduced weight while avoiding any feel of flimsiness.
Over 40 years on, though, that old ABS plastic can turn yellow from UV exposure. The result is that Minolta’s white often appears beige.
The Maxxum 7000 was also the first camera to use Minolta’s new, larger A-mount, as its earlier SR/MC/MD mounts could not handle the needs of AF. This mount was used on Sony’s A-mount cameras produced between 2006 and 2020, and many of the old Minolta A-mount lenses will still work on them.
In 1987, Honeywell sued Minolta claiming that the Maxxum autofocus system infringed Honeywell's patents. Though mostly based on the Leica patents, in 1992 a jury found that Minolta had infringed on two of the Honeywell patents and awarded some $96 million in damages. Minolta also received a license to continue to use the Honeywell technology.
That crippling financial blow was one of the reasons that eventually led to Minolta merging with Konica in 2003.
In 2004, the new Konica-Minolta company introduced its Maxxum 5D and 7D cameras (sold as the “Dynax” outside the USA and the “A-7” in Japan), the first SLRs with sensor-shifting in-body image stabilization (IBIS), which it called “anti-shake.”
This had the advantage that the purchaser bought the system once, with the body, rather than re-buying the IS system with each lens.
Pentax would follow suit in 2006 and Olympus in 2007. All three firms adopted the IBIS system, in part because they had the engineering knowhow – but to a greater degree because they did not have any image-stabilized lenses and thus had no reason not to.
However, the 5D and 7D were the only DSLRs to bear the Konica-Minolta name before it sold the camera business to Sony and left the industry in 2006.
Read more of David Young's ongoing series on classic cameras, as well as his book A Brief History of Photography.
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