Olympus launched their range of single-lens reflex (SLR) cameras with the M-1 in July 1972. The next year this camera was renamed the OM-1, the initials apparently standing for Olympus Maitani, honouring chief designer Yoshihisa Maitani (1933-2009). So began the famed OM System.
This article provides information on the Olympus Zuiko 85mm. The second article will examine the mystery of the different variants. I've now finished a third article that dives into the optical design.
The OM-1 was distinctive in having the shutter dial around the lens mount, a space-saving feature. To improve ergonomics, OM lenses had their aperture dial moved to the front of the lens. This provided convenient one hand control of both essential exposure parameters. While this distinctive feature did not appeal to all photographers, the compact size of the camera system was compelling.
Miniaturisation was taken even further with the half-frame Pen cameras (1959), a name re-used in the digital era for Olympus's micro-four-thirds mirrorless cameras. Though I bought several of those digital models (and also have an original film Pen) I have not owned any OM lenses... until now.
Also released in 1972 is the Olympus F-Zuiko AUTO-T 85mm f/2, though here I have a later variant. Though I already own two 85mm lenses, I was curious about how the tiny Olympus model compares.
Here are the stats, confirmed by Olympus promotional brochures, technical data sheets, and my own measurements. Note: The length specified here is what's visible when mounted on a camera. There are additional projections on the mount, extending back into the body, as is typical for bayonet mounts.
- 48mm long, extending to 61mm
- 280g
- 85cm close focus
- 49mm filter ring
- 8 blade aperture, stopping down to f/16
- 29 degree angle of view
This is sometimes described as the smallest 85mm ever designed for SLR cameras. That's not quite true. The Carl Zeiss T* Sonnar 85mm f/2.8 is the same 48mm in length but extends slightly less, to 56mm. It is also a tad lighter, at 245g. However, it is a stop slower. The achievement of the Olympus engineers with this lens is singular.
Here's a comparison of the OM 85mm with the Zeiss Sonnar 85mm and the Panasonic S 85mm F1.8, a contemporary lens.
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The Panasonic S 85mm is 82mm long but, like most contemporary lenses, is also significantly larger in circumference. But thanks to plastic and new composites the weight is a very reasonable 355g. These Panasonic lenses are indeed excellent, which is why I own three models despite having a preference for the ergonomics and usability of vintage glass.
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The OM lenses use what was then called an "automatic" stop-down mechanism. Even when you rotate the aperture ring the iris doesn't change, but stays wide open. You must press the two switches on the exterior of the barrel to stop down. I've highlighted these blue in the next photo.
An OM camera would have done this automatically. Two levers (highlighted yellow) travel a small arc around the lens mount. The camera uses one of these to set aperture and the other to top down. (Most if not all SLR manufacturers devised a similar mechanism.)
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So be careful when using such a lens on a digital camera. The lens mount adapter must hold the stop-down lever in place, or else the aperture dial will do nothing! I make it a habit of buying K&F adapters since they are inexpensive, have a good fit and tolerance, and always seem to "just work". You can pay many times more for what is essentially a metal tube with the correct screw pitch or flanges in place.
Snap the lens onto the adapter by starting with the K&F logo placed to the left of the position below. Then rotate so the logo lines up with the infinity marking when in place. It is possible to screw on the adapter at other angles, but then the stop-down lever will not be held open. Once on the lens it's rather difficult to take off, given that there are few places where purchase can be obtained.
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I am in the habit of always using a lens hood. This guards against flares that are more likely on older lenses. But more importantly, a short metal hood will protect the front element from damage. Once you add the adapter and hood, a vintage lens loses much of its size and weight advantage compared to a contemporary lens. But it retains the ergonomics and rendering.
My copy of this lens has a very loose aperture ring. I image this is the result of a cleaning / repair job at some point in the history of the lens. After all, it is 40+ years old!
Writers claim that there are anywhere from two to four variants of this lens. They don't agree on the particulars beyond the important fact that there were two different optical designs. Early lenses used 6 elements in 4 groups while later lenses (such as this example) used 5 elements in 4 groups. Photographers enjoy the original for its classic soft portraiture and claim the latter has superior sharpness and aberration correction. With only one sample I can neither confirm nor deny!
In my next article I will explore this mystery and sort out the truth. A deep dive into optical design will also be provided. In the meantime, I am going to see what this lens can do!
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