My photos start with a 1984 camera system, not because that is the beginning of SLR cameras, or even when I started using them, but simply because I have photos available of that era. Photography has been around since the 19th century and no effort is made here to present a comprehensive history of photography, or for that matter a comprehensive history of the Single Lens Reflex camera. I do need to define some terms, however, to make sense out of the recent history that I do intend to discuss.
Terms you need to understand.
Exa IIb and Exakta of the 1960's |
Asahiflex IIA from 1957 with waist Level finder (now called Pentax) |
Spotmatic as introduced in 1964. A Pentax legend for success |
Exakta of Germany is usually given the credit for popularizing the 35mm SLR camera with a successful model around 1936. The Germans had considerable experience with optics and clockworks, and the two combined made a camera. World War II ended production, and after the war the Exakta facilities being in Dresden were trapped in East Germany, and though production resumed after the way, innovation lagged and the leading edge for the development of photography moved to Japan. Never the less my first camera was a low end EXA IIa which I acquired around 1965 (The only photo I could find is of a Exa IIb which was similar, but as I recall had a higher maximum shutter speed. While made by Exakta, it did not bear their name as it was a low end model. It was fully mechanical--- no battery or lightmeter on it. It did have interchangeable lenses using the Exakta mount, an enclosed penta prism and a maximum shutter speed of 1/300. While you could set both the aperture and the shutter speed you needed a separate light meter or you needed to guess at the exposure. At that time exposure estimating instructions were printed on an instruction sheet boxed with every roll of film, (and later printed on the inside of the box) but really for most outdoor situations you could estimate quite well. The 'starting point' for estimating the exposure was a 'bright sunny day'. You would start by setting the shutter speed to the ASA (speed of the film). 'ASA' has since evolved to being called 'ISO' which is an exposure index more or less detached from the film but which still means the same thing. Thus if you had Ecktachrome 64 slide film in the camera you would set the shutter to 1/60 th of second. Then if it was a sunny landscape you set the lens to F/16. Cloudy bright got an F/11, Cloudy not so bright got an f/8 and dreary got an f5.6 or an f/4.
Pentax was one of the first out the gate with 35mm SLR's from Japan. There were in the market in theh mid 1950's ahead of both Nikon and Canon. The heyday of Pentax's importance and domination began in about 1964 with the introduction of the Spotmatic 35mm SLR. I owned one as my second camera. The light meter was fully integrated but not coupled. You got the right exposure by turning the aperture ring or the shutter dial until the light meter needle centered in the viewfinder. Pentax sold aa million of these in a few years.
Unfortunately, the lens mount which Pentax had borrowed from another European manufacturer, though simple was not up to supporting the next generation of cameras. It was just a simple thread mount. You simply screwed the lens into the front of the camera. It is often called 42mm screw mount reflecting the thread diameter. The immediate problem was that they needed at least 2 mechanical connections that would be very accurate in order to implement the next generation camera. The Screw mount had a single mechanical connection for 'stopping down' the lens. You see the lens needed to be 'wide open' for focusing, and needed to be stopped down so the light meter would know how much light was present when stopped down, and for the exposure. The Spotmatic handled this with a simple 'push pin' and a drive plate. The drive plate in the camera body flopped up and pushed the pin when the lens needed to stop down. The plate was fairly large and would work even if the lens wasn't screwed in exactly the same each time. However to make wide open metering work reliably they needed not only to be able to close the lens down on command but also to know where the aperture ring was set. This called for a different type of mount that would register accurately.
In 1975 Pentax changed their lens mount from a screw mount to a bayonet mount. The bayonet mount (a twist lock) was called the 'K' mount and with various adaptations is still in use today. Indeed there exists a screw mount to K mount adapter which allows screw mount lenses to be mounted on today's cameras--even the digital ones allowing every Pentax lens ever made to be used on even Pentax's latest and greatest K10D digital body. "Used" does not mean used with all the features the newer lenses have. The K mount provided just the minimal functions required for the day---2 mechanical connections. It was to work for 9 years without change.
My third camera of significance was a Pentax K2. This was the top of the line model that came out with the introduction of the K mount in 1975. Though only made for a couple of years, it set the base for features expected of cameras of the day. In retrospect it was a transitional model. It was not only fully mechanical in that it would function as cameras had for years without a battery, it was also electronic, in that with a battery the electrics could take control of the shutter and set it anywhere from 1/1000th of a second to 8 seconds to provide the exposure chosen by the light meter. All you had to do was to focus and shoot. Results of course were better if you chose an intelligent aperture setting so the required shutter speed wasn't something ridiculous. The K2 did it all for the day, but was expensive because it was a fully mechanical camera within an electronic camera. I used mine for many years.
The K2 was soon followed by the M series for 'miniature' in which Pentax stripped out the mechanical shutter clock works and made the camera body very small--one of the smallest 35mm cameras of the day. the ME and the ME Super were popular and successful. Also on the low end there was the match needle K1000---an all time best seller that appeared and was successfully sold for over 20 years.
The six contacts added in the KA mount. Only some contact anything on an given lens suggesting they are binary switches |
Pentax perhaps reached their apex with the introduction of the "Program A" or "Super Program" featured in the photos here in about 1983 or 1984. The 'A' series brought a modification to the lens mount by adding some electrical contacts, and the "A" position to the aperture ring. This allowed the 'program' cameras that determined both the shutter and aperture speeds so you only needed to 'focus and shoot'--a big technical step from the K2 design which required you to select a 'sensible' Aperture. However, I did not buy one of these right away. My K2 worked fine, and setting an aperture that was 'sensible' wasn't that difficult so I used my K2 (indeed until I dropped it and broke it) before buying a Super Program over ebay years later. The lens mount with the "A" position on the Aperture ring and the electrical contacts on the mount is known as the KA mount. Pentax has never explained how the series of contacts work on the KA mount but it is generally understood that they provide information relating to the F stop range that the lens is capable of. This third connection was required so that a program mode camera could tell when it was 'out of range' in setting the aperture.
In the late 1980's Pentax made a serious run at the profession photographer market with a full line of lenses from 180 degree fish eyes to extreme telephoto as long as 2000mm, but alas, Nikon and Canon rolled over the top of them. By 1990 Auto Focus was the feature to have. Pentax was an early announcer of a product that wasn't successful and sort of turned their back on the SLR market, instead making huge numbers of low end 'point and shoot' cameras. These small inexpensive cameras generally used 35mm film but did not have interchangeable lenses. Their SLR line was a succession of plastic looking bodies which were mostly forgettable. Although the F series lenses (for Focus) began to appear as early as 1987 (to be replaced with the FA series in a couple of years Pentax was having a hard time on the marketing end with their SLR product line. Though introduced in 1987 the auto focus was so poorly accepted that they continued to sell manual focus cameras for a decade until 1997.
Pentax finally got the bodies right with the ZX series in the mid 1990's (called the MZ series outside the US. While plastic, they were retro in appearance, and I happily bought a ZX5n in 1997 with autofocus, but that is for the next page as this page is about the 'A' series and the Super Program.
The family of 'A' series lenses is huge. Although they did not support auto focus, they were made well after auto focus became available and there are all flavors of primes and zooms. I show here just a few of them in a wide range.
It ranged from 'fish eyes' to an astonishing 1200mm f/8 conventional lens and a 2000mm mirror lens (2 of those heavier than my A*400 f2/8). Pentax also made a couple long zooms that went to 600mm though none were of the A class. As with the lateness of Pentax to the autofocus world they were late to the digital world which required some reworking of their lens family. They did not have to change the mount but the crop factor require a new set of short lenses. The practical effect of the 'crop factor' was to make the effective field of view 50% 'longer'. The longest current production lens for Pentax is presently a 300mm f/4, although the current roadmap calls for an da 560/f5.6 to be introduced in 2012.
Pentax accurately claims that effectively every Pentax lens ever made will work on current Digital bodies and it is mostly true, but there are some limitations. Pentax switched from the M42 screw mount to the K mount in 1975 and there are multiple variations of the K mount around as they have added features to it. The two most notable changes include the addition of communications between the lens and the camera body sufficient to support the program mode. Traditionally the lens aperture was set on the lens, and the shutter speed was set on the camera body, however wtih the advent of the "Program mode" cameras, such as the Super Program, the camera body took control of computing the suitable lens aperture. While the technology for closing the aperture was already present, in order to calculate the correct aperture, the camera needed to know the range of options available. The row of steel balls on the lens flange were added to pass that information. Lens families prior to the 'A' series were not set up to provide this information. Likewise they did not have the "A" position on the aperture ring which effectively alters the mechanics of the lens so the aperture can be set from the camera body. For this reason many of the exposure modes will not work with the pre-A lens familes, but happily they all work in the Pentax-A lenses. What you don't have in the A family is support for the Auto Focus, nor do the lenses communicate their focal length to the camera body.
The SR (Shake reduction) feature needs to know the focal length of the lens, so if you are using a Pentax-A lens (or earlier) you will be prompted in input the focal length of the lens manually when you mount the lens. Also there are emerging features such as auto lens correction, which depend on communications between the lens and the camera body which cannot be supported, but for the most part it is fair to think of the Pentax-A series lenses as fully functional and usable on the latest Pentax bodies in everyway except for the absence of auto-focus.
The 1980's were probably the Golden days of Pentax. They produced the Pentax LX, which was a professional grade body (which predated the KA mount upgrade, and during the 1980's Pentax released a whole family of professional lenses and exotic log lenses. These longlenses are still coveted today. If they have white paint on them and were sold with a trunk for a case they are among the exotic's.