Who Brought Us the SLR?


As SLR users, we are all aware of the many components and features of the cameras we shoot with every day, because the SLR has become the universal standard for today's professional and serious amateur photographers. But where did this highly successful camera design come from, and what turned the SLR into the success that it is today?



The First Two SLRs

While it may come as a surprise, the first SLR camera didn't have the kind of viewfinder we use today! It was built in Hungary in 1948, and resembled a rangefinder camera, using an intricate system of mirrors to project the image onto a small viewfinder. In 1949, Zeiss built on this design, launching the first SLR with a pentaprism viewfinder. Despite their utility relative to rangefinder or large-format cameras, these SLRs weren't perfect, as they lacked features that even film SLR users of the 70's would take for granted. And while most early SLRs originated in Europe, in later years much optical innovation would actually take place in Japan by a company founded in 1919, known as Asahi Optical.


Duflex, the first SLR (left) and Contax S, the first SLR with a pentaprism (right)

The First Japanese SLR

Asahi Optical Company was the first to introduce many of the features that are common in SLRs as we know them today. In 1952, they launched the first-ever Japanese SLR, known as the Asahiflex, which featured an eye-level viewfinder.

The Asahiflex was the first Japanese SLR

The Breakthrough

After spending a few years on improvements for this model (such as the instant-return mirror), Asahi launched the Asahi Pentax in 1957, a camera which would influence the design of future SLRs worldwide.

The famous Asahi "Pentax"

Although the Pentax was not the first SLR to employ a pentaprism viewfinder (as mentioned, Zeiss had done so in 1949), the following features were unique to it, most of which we would take for granted today:

  • An instant return mirror
  • A microprism focusing screen
  • A film rewind crank
  • A right-hand film advance lever (previously, a knob was used) 

These features accomplished that the photographer could finally spend more time looking through the viewfinder, rather than constantly having to take his eye away to adjust knobs on the body. The camera's control layout would eventually be adopted by most camera manufacturers. The camera also featured a new M42 lens mount, which would become standard on other cameras of the era. The Pentax became so popular, that Asahi chose to change their name to "Pentax Corporation," a company which hardly gets any recognition nowadays for its continuing innovation.

The Asahi Pentax influenced the design of other SLRs, such as the MX in the mid-70's

Other SLRs of the 50's and 60's

The modern-day photographic giants, Canon and Nikon, followed in the footsteps of Pentax, each launching their first SLRs (the Canonflex and Nikon F, respectively) in 1959. While the Canonflex seemed to be two steps behind the competition, the Nikon F—which employed all of the features of the Pentax—was targeted at professionals, and demonstrated the superiority of the SLR, as well as the high quality of Japanese camera design. For the next 40 years, the SLR would be the camera of choice for professional photographers.


The first Canon and Nikon SLRs, both launched in 1959

Throughout the '60's and '70's, innovation continued at all Japanese camera companies, but Pentax continued to stand out as one of the most popular and successful manufacturers. Early on, the company set a precedent of elegant design and affordable pricing.

The Pentax Spotmatic, launched in 1964, was one of the first cameras to feature through-the-lens metering, and arguably the most successful camera of the decade. Its design was kept for later Pentax SLRs, including the K1000, which became one of the most popular cameras among students and was produced through 1995.

In 1971, Pentax launched lenses with the world's first multi-layer anti-reflective coating (SMC), something that practically all modern lens manufacturers have adopted. Two years later, the Pentax ES marked the world's first SLR with stepless electronic aperture-priority auto exposure (Av mode), meaning that its calculated shutter speeds were not confined to pre-determined intervals.

The First Autofocus SLR

In 1981, the ME F entered production, which was the world's first commercially-available autofocus SLR.

The Pentax ME-F, with a normal 50mm lens

As stated by the Asahi Optical Historical Club, "The history of Pentax cameras is the history of the step-by-step development of the 35mm SLR, from the awkward equipment of the early days to the winning concept outperforming all other types of cameras. Pentax can claim more world's firsts and SLR improvements than any other manufacturer in the world."

The Decline

Unfortunately, due to poor performance, the AF technology used in the ME F was not a success, and Pentax had to rush to design an entirely new system, which was launched in 1987. Although this autofocus system was among the first out there, and Pentax again came out with something new—the first SLR with built-in auto flash—in the following years the competition began to overtake Pentax, making their products become less and less noticed.

The Pentax SF-1, the first AF film SLR with built-in auto flash

Pentax continues to bring innovation to their SLR cameras today! Their latest flagship, the K-5, was determined by DxOmark to have the highest image quality among all APS-C SLRs.

If you were an owner of a Pentax SLR, you would also know that:

  • They support more lenses than any other camera. Every Pentax lens produced since 1952 can be used (some requiring adapters), as well as thousands of third-party lenses.
  • They're priced below the competition, and are ideal for beginners.
  • Looks are deceptive. Pentax SLRs have some very advanced features, even in beginner models.
  • All modern Pentax bodies feature Shake Reduction, meaning that all your lenses, new or old, become instantly stabilized!


The digital Pentax K-5, featuring best-in-class image quality

To see more Pentax masterpieces from the past and present, check out the camera and lens databases over at PentaxForums.com, which has details and photos of all modern and historical SLRs and lenses.

If you'd like to join the club, check out PentaxForums.com, the largest site dedicated to Pentax users! Also, don't forget to visit us on Facebook. We regularly hold giveaways, sponsored by B&H!


I have owned Pentax Cameras from 1983 with the ME-Super and Auto 110 to the K100D and K20D. I own 16 vintage Ashifles and Pentax SLR's and two DSLR, I will only own Pentax cameras. And two P&S Pentax 35mm cameras.

Actually the first the first Japanese SLR to use a pentaprism is the Miranda Orion: 1954 for the first prototypes and 1956 for the finished product.

Worlds first penta prism slr camera was ITALIAN! Presented at the Milano Fiera spring 1948 and produced from September the same year, it was available one year before the Contax S, which had been officially presented in Leipzig in March 1949. The Duflex was not a penta prism camera, but rather a sophisticated construction of mirrors called porro prism. It was known from 1947, presented in June 1948 and market ready from february 1949. Please read www.pentax-slr.com for more detailed information on pp slr history. For studying Rectaflex, read Marco Antonettos Rectaflex, the Magic Reflex. Nassa Watch Gallery 2002. Can be found on the net.

  I am a diehard fan of Pentax cameras and still like to have one.Thanx.

No mention of the Exakta? This was the first 35mm SLR, introduced in 1936.  It predated the Duoflex or the Contax D (the 1949 Zeiss SLR).  It was the Exakta which set the design pattern which all 35mm SLR cameras were to follow later.

thanks for the information about SLR Cameras..