The Olympus OM System: A Brief Overview


Olympus’ OM system set the camera world ablaze when it was released. By cleverly combining the best features of compact rangefinders and larger SLRs, the OM series started a chain reaction that miniaturized cameras from all manufacturers.

But what makes the OM system so unique? And why does it have such staying power despite only having 4 models and very slight changes to the body style over decades?

Nuno and Nico are here to tell you, and share some wisdom about the OM system in general. Keep scrolling for the text version!


Olympus was late to the SLR game. They had witnessed the birth of the modern SLR when Nikon released the F in 1959, but decided not to enter that market.

1959 was the same year that designer Yoshihisa Maitani came up with the ingenious half-frame PEN camera. The compact size and elegant simplicity of these cameras would define Maitani’s career, and with it the industrial design language of Olympus.

Designing the OM

After the PEN line had been fleshed out a bit, Maitani and his design team were tasked with building an SLR for Olympus. The body was meant to differentiate Olympus from the market by being significantly more compact than the competition without sacrificing features or build quality.

At first, they attempted to design a modular 35mm SLR system, akin to a miniature Hasselblad. In the end, though, they created something much more traditional and iconic.

The result was the Olympus OM-1. Or, sorry, the M-1. Olympus added the O after a certain German brand with their own M cameras told Olympus to cease and desist.

Upon its release in 1972, OM-1 was an instant classic. It truly did take the features of other professional SLRs and fit them into a much smaller package without sacrificing quality. The mechanical nature of the camera ensured reliability, and the viewfinder was big and bright.

Olympus was able to further shrink the lenses by expanding the lens mount outwards. They used the extra space to relocate the shutter speed ring towards the base of the lens. This made both creative settings easily accessible with one hand.

Overall, the OM-1 was revolutionary, countering the large, heavy professional SLRs of the time and proving that smaller cameras could still produce professional results. Cameras like the Pentax MX and Nikon FM owe a lot to Olympus for pushing the boundaries of camera design. The risk they took with the OM-1 opened up an entirely new segment of the market for compact professional SLRs.

Expanding the Lineup

And Olympus didn’t take their feet off the gas, either. In 1975 they released the OM-2. Just looking at the camera, it's fair to not be sure what changed. But the OM-2 features advanced metering systems and the ability to shoot in aperture priority auto-exposure. The body remained compact, but now the shutter was electronically controlled. 

The body shape similarity also made it so that all OM accessories fit both the OM-1 and OM-2, which saved Olympus quite a bit of time and money.

From there, the OM-1 and OM-2 would be the stalwarts of the Olympus brand for years. In 1979, Olympus introduced the OM-10, a consumer model that only had access to aperture priority shooting. This consumer line with 2 digit numbers would continue into the 1990s.

The next major upgrade to the OM series, however, was the introduction of the OM-3 and OM-4 in 1983. For this line, Olympus updated the OM-1 and OM-2 respectively. These cameras shared the same relationship as their predecessors, as well. The OM-3 was mechanical, with no auto-exposure, and the OM-4 allowed for program shooting and aperture-priority exposure.

The big upgrade, though, was in metering. The OM-3 and OM-4 share one of the best meters ever seen in an SLR. This meter allowed a photographer to select the highlights and shadows of a scene and have the camera evaluate the proper exposure based on those two readings. This multi-spot meter, combined with a normal spot meter and center-weighted evaluative metering made the OM-3 and OM-4 incredibly capable cameras.

Like many systems, though, the OM mount was not prepared for autofocus. Although the OM-707 did have autofocus, this camera failed to earn the praise of earlier Olympus cameras and the OM system fell by the wayside. 

Olympus would put their entire consumer line on hold by 1992, and only introduce one new camera with the OM mount after that. Cosina designed and built 1997'2 OM-2000, however.

The reason for the decline and abandonment of the OM system was two-fold. First, autofocus was hard to implement in this system and, like Canon and Minolta, Olympus would have had to redesign their mount from scratch.

The second reason is a move towards digital. Olympus was a pioneer in the digital market, bringing bodies to the market in the mid 90s that had more than double the resolution of their competitors. While their digital imaging may not be as productive or profitable these days, there was a time when Olympus was on the bleeding edge of technology and research.

Olympus’ commitment to compact cameras and innovation shows in their modern line of Micro Four Thirds mirrorless cameras. The design language of these bodies strongly echoes both the OM series and the earlier PEN half frame cameras.


The OM system, aside from the very few autofocus lenses designed for the OM-707, are all fully compatible with one another. Unlike other manufacturers, Olympus chose not to segment their lenses into different price and build quality sections.

This means that each OM lens had the same professional standard, whether they were on a pro or consumer body. Switching between a normal Canon lens and an L lens, the difference in quality is clear. 

The same goes for Nikon’s Nikkor line and Series E lenses from the same era. Olympus’ thinking on this was a bit different, and their lenses have achieved popularity across the board because of it.

Size is the other important factor to Olympus lenses. Because they’re a bit further from the film plane than some of their competitors, the lenses are incredibly compact. The normal 50mm f1.8 lens, for example, would be a pancake option on any other system.

People love some of their lenses, like the 90mm f2 and 100mm f2.8, for their sharpness and compact size. The 24mm lens is smaller than its own lens hood!

The OM mount also received considerable support from 3rd parties who viewed it as an important market. Companies like Vivitar, Tamron, and others made their lenses with OM mounts as well as Canon, Nikon, and Pentax.

The lenses, in general, follow the same principle as the bodies and remain as compact as possible without sacrificing quality in any way.


As mentioned, the OM series has two lines; professional and consumer-grade bodies. The simple way to differentiate them is by their names. Professional bodies will have single digit numbers, and the consumer-grade ones will have multiple numbers.

The OM range is one of the easiest systems to understand. The professional lineup is only 4 cameras, although there are some variants of each. 

The OM-1 had a few variations to allow for a motor drive and some other quality of life features. Olympus gave the OM-2 a spot meter and program mode in 1984.

Beyond that, though, the OM-3 and OM-4 each received a titanium-plated premium model but remained the same during production.

The consumer cameras have a bit more variation. The OM-10, 20, 30, and 40 were all sold concurrently and offered similar feature sets. The OM-10 is the only one not capable of shooting in manual mode without an adapter.

The OM 20 and 30 were identical except for a quick focusing LED in the 30 that confirmed focus for the photographer. This also enabled the OM-30 to achieve a quasi-autofocus, allowing the camera to automatically fire the shutter when an object came into focus.

The OM-40 was a sleeker, lighter, plastic body that added a basic form of matrix metering and mirror lock up functionality.

The OM-77 and OM-88 were ill-fated autofocus bodies that ditched the design ethos of the previous OM bodies. The 77 was more feature-packed, and clearly took design influence from the very popular Minolta 7000. 

The 88, on the other hand, aimed squarely at amateurs and had very few features. Neither of these cameras did well on the consumer market, and Olympus had to reassess their SLR system.


OM lenses are adaptable to every major mirrorless system, as well as some SLR systems like Canon EF. The lenses are readily available and of exceptional quality, so they are popular choices for adapting.

This has led to a price increase in recent years of most Olympus lenses, especially those of desirable focal lengths. The 50mm lenses remain quite affordable and in-line with offerings from other manufacturers.

Who Is It For?

Olympus bodies are generally affordable and compact. The OM-1 in particular deserves to be among the ranks of ideal beginner manual cameras, right next to the Pentax K1000 in popularity. 

When comparing the OM-1 to its competition in the Pentax K1000, Minolta SRT, and Canon FTb, it’s clear that the OM-1 stands alone due to its size. This size, however, can be a downfall as well. Some people will not like the small size, or perhaps will struggle with the placement of the shutter speed dial. 

The counterpoint to this argument, though, is that adding the battery winder and 4 AA batteries to an OM-1/50mm f1.8 kit makes it about as heavy as a standard Nikon F3 with a similar lens.

If small size is important and you don’t need to swap out prisms, then the OM professional bodies should be near the top of your list for sturdy, classic cameras. The consumer grade cameras offer a great price point and access to advanced metering.

They also retain a manual film advance, small size, and other features that some consider part of the “process” of film photography. Compared to cameras like the Canon T70 or Minolta 7000, the OM-xx series has more traditional controls with the same low price point. Whether the traditional nature of the controls is a positive or negative thing is entirely subjective.


Although only running for 20 years, the OM system flipped the SLR market on its head. Maitani's design team completely changed what was valued in an SLR by the public. They miniaturized the professional SLR and showed that feature cutting was not necessary to cut size.

Olympus also incorporated advanced metering technology in a more effective way than a lot of their competition. The multi-spot metering of the OM-4 was an incredible feat of technology, and paired well with wonderful design that made the feature easy to understand and implement.

I think it’s fair to say that the design of the OM-1 shaped the entire system. That compact body set the stage for Olympus’ history of pushing the boundaries of camera design. 

This trend lives on in the OM-D series of mirrorless cameras still sold today. The dream of Maitani and the direction he pushed became Olympus’ guiding light. This design is what defined them in a crowded 35mm market.

If you want a solid, reliable, and compact 35mm SLR system, then look no further than the OM system.

This article was originally published on 27.11.2020.

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