The Olympus OM System

Progeny and Progenitor (OM PC aka OM-40 and the classic OM-1)

 
   Welcome to the fourth installment of our "Choosing a Vintage SLR System" overviews! It features Olympus, one of the most influential Japanese camera manufacturers. We will work our way through: 1) Lenses, 2) Bodies, 3) Flash, 4) Accessories, and 5) Reliability & Servicing. But first...a little introduction :-).​

​    Olympus first came to prominence in photography in the late 1950s and early '60s with their half-frame (18x24mm, which was half of the 35mm frame) Pen series of cameras specifically targeted at the Japanese and later, the European markets. They were designed to be affordable for the average worker and economical to operate while still providing decent quality for an 8x10 print. Olympus sold millions of Pens. Ironically, it was the refusal of Kodak to support the half-frame format in the USA that pushed Olympus into the 35mm arena. For a more in-depth look at this turn of events, see this article. Although Olympus was the last of the major Japanese manufacturers to get into the 35mm SLR game, they made quite the splash in 1972 when they finally joined the fray. The immense influence Olympus exerted on the photographic world was due, in large part, to the efforts of the brilliant designer Yoshihisa Maitani and his team of engineers. The creator of the Pen and OM series was always seeking to do something different, not just copy others, and this does much to explain the success of Olympus over a three-decade period with its film-based equipment. The OM series would do more to reduce the size and weight of 35mm SLRs than any other system. What is more interesting was the impact this had on the other, more well-established manufacturers (Canon, Minolta, Nikon, & Pentax) known as the "Big 4". By the late-'70s, that designation had to be changed to the "Big 5", due to the success of the OMs. So let's take a closer look at all the OM system has to offer.

  Lenses

​    The Olympus OM Zuiko ("blissful light") lens family covered from an 8mm fisheye to a 1000mm supertelephoto with a variety of maximum apertures in the 21mm to 350mm range. There was a full set of primes and many zooms, along with macros, and some specialty lenses. They were known for their compact size and overall performance. Many OM lenses were set apart from most other 35mm SLR lenses by their location of the aperture ring at the front of the lens (a la the Leica M rangefinder lenses). Olympus used a large bayonet mount that enabled them to offer a range of f/2 lenses from 21mm to 250mm. It was the most extensive lineup of f/2 primes offered by any manufacturer in the film SLR era. The more moderate maximum aperture OM lenses were renowned for their compact dimensions and lighter weight than their competitors. 

   
    Zuiko Nomenclature. There were up to five generations of OM Zuikos depending on the particular lens. It can be somewhat confusing when differentiating them as the terminology was not consistent across the lineup or generations. Especially when it comes to coatings can things get a little murky. Some lenses with multi coatings have no markings to indicate such, while others had the "MC" marking on the front nameplate of the lens right from the get go. One thing that was consistent across all versions was the use of a suffix (-S, -W, -T) following the word AUTO, that designated the lens as standard, wide angle, or telephoto. AUTO stood for automatic aperture, meaning that the aperture closed and reopened without any intervention from the photographer.

• First-gen OM lenses had the edges of the filter ring and lens barrel bevelled and left unpainted and they are thus known as "silver" or "chrome" noses. Pertinent information about a lens was engraved on its front nameplate. On the first and second generation lenses, Olympus used a single-letter code followed by a period and the word ZUIKO to signify the number of glass elements in each lens.  A = 1, B = 2, C = 3, and so on (e.g. the 50/1.8 was an F.ZUIKO, signifying its 6-element construction). Most of the high-speed (f/2 and faster) lenses had multi coating while the standard speed lenses (including the 50/1.8 & 1.4 and the 55/1.2) were single coated. Some of the silver nose multicoated optics had "MC" & "Japan" engraved on the front nameplate and did not have a letter code for the number of elements. And some had "Japan" and a letter code. See what I mean about the lack of continuity :-).  

• The machined bevel was eliminated on second-gen OM Zuikos and so the filter ring and lens barrel were now totally black.
• When the third-generation OM Zuikos came along, the single-letter code was dropped, and the letters "MC" added to denote the use of multi coatings on many lenses that did not previously have them. However, just because a lens lacks the "MC" code does not necessarily mean that it is not multi coated. 
• By the time the fourth-gen series came along the "MC" marking was being eliminated as multi coating had been extended throughout the entire lineup. "Japan" was now engraved on lenses that did not already have it.
• The last generation of lenses had "made in japan" engraved instead of "Japan". These are often looked upon as the most desirable Zuikos, as they had the most modern coatings and optics.

   Features. The first thing many people notice with most Zuiko prime lenses is the location of the aperture ring at the front of the lens (with f/ numbers decreasing from left to right). (The big telephotos & zooms used the conventional SLR layout of having the aperture ring at the rear of the lens.) As stated earlier, this followed the Leica M lens configuration. But it was not just for stylistic reasons that this arrangement was adopted; having the aperture ring at the front of the lens was helpful in preventing tactile confusion with the standard shutter speed ring location of most OM bodies (concentric to the lens mount). OM Zuikos also featured distinctive diamond-pattern rubber focusing grips and focused counter-clockwise toward infinity. A depth of field (DOF) preview push button was included on every OM Zuiko lens (excepting the 500mm catadioptric telephoto with its fixed aperture of f/8), which was a nice touch as most other manufacturers used body-mounted preview levers that would generally be deleted on base models. This design thus allowed DOF preview even with their low-end consumer bodies. Olympus' multi coatings, while not necessarily cutting edge, were capable. Newer lenses obviously had more advanced coatings and that may be preferable for many OM users, but excellent results can be had with single-coated lenses when their limitations (such as not pointing them into direct sun) are respected. Focusing helicoids were a mixture of aluminum-on-aluminum, and later plastic-on-plastic for some of the lower-end lenses (such as the late 50/1.8). They can get stiff with age, but a clean and re-lube will take care of that. The standard filter size was 49mm, with 55, 72, and 100mm rounding out the range. For some large, high-speed telephotos a 46mm drop in filter was used.

   Noteworthy Lenses. Olympus originally focused on lenses with average maximum apertures but in a much more compact package than their competitors. They were very successful in this, as evidenced by Minolta's and Pentax' efforts in the late 1970s to reduce the size and weight of their lens lineups to compete with the OM Zuikos. In the early 1980s, with the introduction of the OM-3 & OM-4 bodies as replacements for the OM-1n & OM-2n, Olympus set out on an aggressive expansion/update of its lens inventory. They set about creating a two-tier lineup, with the series of fast f/2 primes being filled out for advanced amateurs and professionals to supplement the existing standard aperture lenses. These fast f/2 primes, while necessarily larger than their smaller-aperture counterparts, continued the Olympus tradition of big performance in a compact package. No other Japanese SLR manufacturer boasted such an extensive selection of f/2 optics: 21/2, 24/2, 28/2, 35/2, 40/2 (pancake), 50/2 Macro, 85/2, 90/2 Macro, 100/2, 180/2 & 250/2. The 21mm to 100mm lenses (with the exception of the 35/2) all featured floating elements that shifted at close focusing distances for improved performance. This was not unusual for wide angles, but Olympus was the first to use floating elements in medium telephotos (such as the 85 and 100mm f/2s).   

    The 180/2 & 250/2 were definitely pro-oriented, with ED (extremely low dispersion) lens elements, internal focusing, white-painted barrels (to combat shifting of lens elements due to heating), and heavier weights (1.9kg & 3.9kg, respectively) resulting from such high-specification construction. Although not an f/2 optic (which would have been excessively unwieldy), the 350mm f/2.8 ED-IF was the final member of this telephoto triumvirate (the f/2.8 maximum aperture helping to keep the weight identical to the 250/2).   ​

   
​    Due to their strength in microscopy and other high-magnification medical applications, Olympus placed a high priority on macrophotography with the OM system and it boasted a great variety of dedicated macro lenses and accessories. They were not designed for the casual user, but for true macro enthusiasts and professionals. There were four lenses dedicated to macro introduced in the early '70s: MC Macro 20/3.5, MC Macro 38/3.5, MC AUTO Macro 50/3.5, and the MC Macro 80/4. The 50/3.5 was the only lens among these that utilized a standard focusing helicoid (the others were all designed for use with bellows, with the 80/4 having a helical fine-tuning adjustment). The 50/3.5 was also unique in being the first 50mm macro lens to use a floating elements design to ensure top-level close focus performance while retaining excellent performance at longer distances, making it a very versatile lens. Other 50mm macros, lacking floating elements at this time, had to sacrifice performance at normal distances to achieve such high-level performance at close range. The OM 50/3.5 also provided full-aperture metering while the other OM bellows macros required the use of stop-down metering.

    Again, in the mid-'80s, Olympus gave the macro lens lineup a major makeover: the new AUTO-Macro 20/2 not only gained 1 1/2 stops of speed, but also an automatic aperture (like the 50/3.5) and the helical fine-tuning adjustment of the 80/4;  the new AUTO-Macro 35/2.8 similarly replaced the 38/3.5, with all of the improvements of the 20/2 incorporated; the AUTO-Macro 80/4 was given the automatic aperture treatment as well as a new Auto Tube 65mm - 116mm accessory (basically a zooming extension tube), which allowed up to 2X magnification with auto aperture and meter coupling. The AUTO-Macro 135/4.5 came long about this time and was designed for use with bellows or the Auto Tube. The 50/3.5 morphed into an f/2 version, which made it the fastest 50mm macro available at the time. The final member of the AUTO-Macro family, the 90/2, came along in the late '80s and was ​capable of a 1:2 image ratio on its own and could achieve higher than 1x magnification with the Auto Tube or bellows. With its floating elements and fast aperture it could serve very well as a standard medium telephoto with the bonus of macro. It also offered a more convenient working distance than the 50/2 Macro, making it a more versatile lens. ​For any architectural photographers out there, Olympus offered two shift lenses (sorry, no tilt), a standard 35/2.8 version and a more interesting 24/3.5 ( the widest shift lens available at its time of introduction).

    As far as zoom lenses went, Olympus focused the greater portion of their attention on the consumer and enthusiast markets. One of their better zooms was the Zuiko Auto-Zoom 35-70mm f/3.6. There was also one late full-on professional zoom: the Zuiko Auto-Zoom 35-80mm f/2.8 ED. It definitely takes the top position among Zuiko zooms as far as performance and capability are concerned. It also remains quite expensive due to its rarity. 

    Recommendations. The fast primes and the rare 35-80/2.8 zoom are among the highest priced vintage Japanese MF (manual focus) optics available today. Prices run on average from a mild $150 USD for the 35/2 (bargain!) to $2900 USD for the 350/2.8. The 35-80/2.8 ED, while very capable (and pricey at $800 - $900 USD), is a big chunk of glass to put on the front of the svelte OM bodies, so it is a bit of a departure from the Olympus ethos of compact and lightweight performance. Rarity and demand push the prices with these lenses. As an example: the smallest prime Zuiko ever made was the 40/2 pancake lens; it was only on the market for five years, and though originally priced cheaper than the 50/1.4, it now goes for $250 - $600 USD. Compare this to the 28/2, which originally sold for two and a half times as much, but can now be had for $200 - $300 USD. If you can afford the f/2-level primes, you will likely not be disappointed with the results. But remember, there will be a weight/bulk penalty (albeit a smaller one than with other manufacturers) compared to the standard aperture lenses. It is a personal decision as to how much that extra light-gathering capability is worth.   

    As with most other orphaned MF systems, the real bargains are to be found among the smaller-aperture primes, standard lenses, and enthusiast zooms. A big draw for many Olympus users is the compact dimensions offered by the combination of these lenses with the OM bodies. Some of these lenses with a reputation for very good to excellent performance, in a small and affordable package, are: the 24/2.8, 28/2.8, 28/3.5, 35/2.8, 50/1.4, 50/1.8, 100/2.8, 135/3.5, and the 200/5. Just as a reminder: many of these came only in single-coated versions or only gained multi coating later in production. While any lens will benefit from using a lens hood, with single-coated optics, it should be considered mandatory (unless you deliberately want such effects :-)) to preserve contrast and reduce flare and ghosting as much as possible. Don't be put off by the plastic helicoid construction of some of the late lenses, most of them are better optically than their predecessors, and the durability of the helicoid is not a worry. The 35-70/3.6 was a high-quality zoom that now sells for $50 - $70 USD (about a tenth of its original price!), making it one of the best bargains of the entire OM Zuiko lineup. Prices are low for a couple of the tele-zooms, the 65-200/4 and the 50-250/5, but approach them cautiously as the are both known to suffer from a "self-frosting" rear element that obviously impairs image quality. Do not buy one sight-unseen.

    If you are interested in macrophotography, the OM system has a lot to offer...at a price. The 80/4 and 135/4.5 lenses are the least expensive lenses (around $140 USD bare), but they require bellows or the Auto Tube to be usable (they can be had with the AT for around $250 USD). From there, the prices just keep going up, with the 50/2 going for $250 USD; the 38/2.8 (again requiring bellows/AT) at $300- $400 USD; the 20/2 (+ bellows/AT) at $500 - $700 USD; and the versatile 90/2 rounding out the list at $650 - $800 USD. The older non-AUTO macro lenses are somewhat less expensive, but require more input from the photographer because they require stop-down metering. The Auto Tube is probably the most helpful macro accessory, as it allows fully-automatic aperture operation with Auto-Macro Zuikos while allowing you to reach greater than 1X magnification with any of them. It can most easily be found in a package with one of the macro lenses. The Auto Bellows can be had for $70 - $100 USD, which is quite competitive with other systems and allows for even greater magnification ratios.

 
​  Bodies

    Mechanical SLR Bodies

    OM-1. Olympus took the 35mm SLR world by storm with its initial offering, the OM-1, at Photokina 1972. The OM-1 was originally designated M-1 (for its designer, Yoshihisa Maitani), however, due to Leica raising a stink, it was changed after the first production run had come off the line. Aside from its size, weight, and control configuration, the OM-1 was similar in technical specifications to its competitors. But in those three areas, it was a revolution. Cutting size by 5 - 13% and weight by up to a third of its rivals, while still retaining the same level of capability, was a coup for Olympus. Control-wise, it featured the ISO dial (range: 25 -1600) in the location where most other manufacturers had the shutter speed dial. Shutter speeds were controlled via a ring concentric to the lens mount (a la the Nikkormat FT series). The shutter was of the traditional horizontal-travel, rubberized-silk type with a range of 1/1000 to 1 sec. + Bulb. The film rewind release was on the front right panel of the body, rather than the bottom plate. The OM-1 was aimed at enthusiasts and professionals. Metering was via 2 cadmium disulfide (CdS) cells powered by a single 625 (1.35V) mercury cell. It was the only OM model to have manual mirror lock up (MLU) capability. It also eventually featured 14 interchangeable focusing screens. The viewfinder had an impressive 97% view at 0.92x magnification, making for one of the best viewing experiences with any vintage SLR (although eye-relief could be an issue for some users). The original OM-1 did not have motor drive or power winding ability. This was remedied in 1974, with 19 other internal improvements to the body. The early models had an MD sticker denoting the change by the rewind release lever. Succeeding motor drive-capable OMs have a small, square MD logo on the lower left side of the lens mount. A third-iteration, the OM-1n, appeared in 1978, with an additional 34 improvements over the OM-1MD. The OM-1n was on sale until mid-1988 (although it had been out of production since 1987), for an impressive 15-year run with the entire M-1/OM-1 series.

    OM-3. The OM-3 was introduced at PMA '83 and went on sale in mid-1984 as part of Olympus' massive effort to overhaul and update the OM system. It was derived as a mechanical version of the OM-4. The shutter was upgraded to a 1/2000 sec. top speed with 20 other improvements to the OM-1 shutter assembly. But the big news was a new silicon photo diode (SPD) metering system capable of both centerweighted and spot readings (with both highlight and shadow-based methods). The metering display was now LCD instead of match-needle. ISO range was increased: it was now 6 - 3200. The viewfinder magnification was reduced to 0.84x (still pretty good) and a built-in diopter adjustment was now included. It lacked the MLU and self-timer functions of the OM-1. That it was aimed at pros and advanced amateurs was not in doubt, as it sold for nearly three times the amount of the OM-1n (which remained in the line as a budget model). The OM-3 suffered the misfortune of bad timing. The autofocus revolution came to 35mm SLRs within months of its sales debut. Demand for a full-featured, mechanical, manual focus SLR was limited, to say the least. The OM-3 was discontinued in 1986, and by October 1988, it had all but disappeared from dealer's shelves. But there would be a resurrection of sorts for the OM-3. In late-1994, Olympus brought forth a titanium bodied version of the OM-3, the OM-3 Ti. The OM-3 Ti gained the high-speed TTL flash capability of the OM-4 Ti. It was the most expensive body in the OM lineup, ever. In 1999, it sold for $1500 USD; $380 more than the OM-4 Ti. The OM-3 Ti was discontinued by mid-2002.    

    OM-2000. This was an Olympus-badged, Cosina-built SLR. It appeared in 1997 as a low-cost alternative to the advanced and expensive OM-3 Ti. It had a 1/2000 top speed, true multiple exposure capability, spot metering, and a 1/125 sec. flash-sync speed due to its vertical-travel shutter. It did not offer: TTL flash, interchangeable focusing screens, or motor drive capability. It feels cheap, but it works quite well. It would be a decent alternative to a higher-end body for taking into riskier situations, if you could find one inexpensively. And there lies the conundrum, OM2000s are often priced as high or even more than OM-1s, without the build quality.

    Recommendations. Our top recommendation for a mechanical Olympus is the OM-1n. It had the benefit of several years of refinements over the original that increased reliability and versatility. For anyone requiring manual MLU, OM-1s are the only game in town in the entire OM series. None of the OM-1s offered TTL flash metering. The mercury cell issue can be dealt with by installing a diode internally to allow the use of a modern 357/S76/SR44 battery, or by using the C.R.I.S. MR-9 adapter that allows the use of a smaller 386 silver-oxide battery with its output attenuated to 1.35V. Another alternative is using a handheld meter. The OM-1n is fairly plentiful on the used market and therefore comparable in cost to its contemporaries of other brands. The biggest issue with the OM-1 (& -1n) is the deterioration of the foam used to seal the pentaprism in place. Over time, it eats the prism coatings causing black or greenish/gray patches or lines to appear in the viewfinder. It is strongly recommended to get the foam cleaned out to prevent this and/or find a donor body with a clean prism to replace an already-damaged one. A CLA (clean, lube, adjust) should seriously be considered at the minimum when contemplating the purchase of one of these bodies. An overhauled OM-1n will give years of excellent service. Many users claim that the OM-1/-1n (& OM-2/-2n) film advance is smoother than the OM-3/-4 generation of bodies. The money you save (versus an OM-3) can be used to better effect for lenses or other accessories. 

     You can sometimes get your hands on an unserviced OM-3 for $300 - $400 USD. For a significantly smaller amount you can get an completely overhauled OM-1n (including the purchase of the body and battery conversion). An issue that sometimes crops up with the OM-3 (and its electronic siblings, the OM-4 & OM-2S) is a high rate of battery drain due to issues with the internal circuitry. This can be a turn-off for many prospective users. A more in-depth look at this problem and how to make the best of it will be dealt with in the electronic OM body section. By the time OM-3 Ti came along the circuit had been revised and the problem mitigated. The big downside of the OM-3 Ti is that it remains among the most expensive of manual focus Japanese 35mm bodies. Its rarity (reportedly, only 4,000 were produced) and desirability in the eyes of collectors keep prices very high (some would say they are very overpriced ;-)). A recent (late 2016), new-in-the-box example sold for $3,500 USD. Examples with average wear commonly sell in the $1,250 - $1,500 USD range. All single-digit OM cameras can suffer from a worn film advance clutch which causes overlapping frames, particularly toward the end of a roll of film. This is easily remedied with a good servicing. John Hermanson @ zuiko.com is a former factory-trained Olympus technician providing service for the OM system, which includes battery conversion for the OM-1. You would do well to check out his website if you are serious about the OM system. Be aware that this is not his day job, so there is an approximately 8 week turnaround time (as of Jan. 2017) for his services. (He does have a Pro Rush service available for a higher cost.)    

   Single-Digit Electronic SLR Bodies

   OM-2. The OM-2 came out in late-1975 with an electronically-controlled shutter, aperture-priority (offering stepless shutter speeds) and manual exposure modes, and introduced TTL (through the lens) flash metering to SLRs. The OM-2 came with two (count 'em) metering circuits. It could measure down to -6.5 EV (120 seconds @ f/1.2) in aperture-priority (AUTO) mode at ISO 100 on paper. Metered exposures of up to 19 minutes are available at ISO 12 (the lowest ISO) and 20 seconds at ISO 1600 (the highest ISO), which were somewhat more than specified. It took 4 years for anyone else to utilize TTL flash metering (Contax 139) and 5 years to even come close to matching the sensitivity of the AUTO meter (Pentax LX). The manual exposure mode used the same CdS (EV 1.5 - 17) metering circuit as the OM-1, meaning that the OM-2 was really intended to be used in aperture-priority to utilize the full extent of its capability. There was a 4-position metering switch (OFF/Manual/Auto/Battery Check) instead of the 2-position (OFF/ON) of the OM-1. The ISO setting function was combined with an exposure compensation dial of +/- 2 EV in 1/3 steps. Early OM-2 bodies used a centerweighted metering pattern on the shutter curtains. At some point in OM-2 production, the pattern was changed to an averaging one. One bonus is that the OM-2 was designed from the outset for 357/S76/SR44 silver oxide batteries, so there is no conversion hassle as with the OM-1. In 1978, Olympus brought out the OM-2n alongside the OM-1n. The biggest change from the original OM-2 was a 3 1/2 minute maximum metered exposure limit (to prevent excessive battery drain from holding the shutter open for extended periods) and a fixed speed of 1/60 second for TTL flash. This means that the original OM-2 offers a bit more flexibility in long exposure or flash photography if your needs require it. The OM-2n introduced an exposure compensation (EC) LED that lit up in the viewfinder whenever EC was engaged. 

    The replacement for the OM-2n, the OM-2S PROGRAM (aka OM-2 SPOT/PROGRAM) was actually a derivation of the OM-4 rather than a direct iteration of its namesake. Introduced a year after the OM-4, in the fall of 1984, it went on sale in early 1985 and was intended to be a middle-of-the-road OM, bridging the gap between the consumer-level double-digit models and the pro-oriented OM-4. Its construction was solid single-digit. New features included:

• a Program mode that set both shutter speed and aperture
• the final metering check required in Program mode caused a reduction in top motorized advance speed to 3.5 fps from the 5 fps of the OM-2/-2n 
• a Manual/Spot mode that used spot metering (covering 3% of the frame area with a 50mm lens) instead of centerweighted; Manual mode was the only one that could use spotmetering
• a mechanical backup speed of 1/60 sec.
• the lowest metered exposure value was reduced to -5 EV from -6.5 EV (OM-2/-2N)
• ISO range was now 12 - 3200
• the viewfinder display was now an LCD instead of match-needle
• there was user-selectable illumination for the viewfinder
• the mode selector was now concentric to the rewind lever and the OFF position was eliminated
• the self-timer was now electronic and include mirror pre-fire
• the hot-shoe was now integrated instead of detachable

    The use of much of the OM-4's metering circuitry led to the same battery drain issues with the OM-2S. Not all copies are affected, so it's a bit of a crapshoot as to what you will get. If a body does have this problem, using silver oxide 357/S76/SR44 batteries is the best way to extend battery life, along with removing the batteries anytime the camera is going to sit for more than a couple of days. Production ceased in 1987.

    OM-4. The OM-4 was the final electronic-shuttered professional model in the OM system. As a replacement for the OM-2n at the top of the OM line, it was basically an electronically-controlled OM-3 with TTL flash metering. When it went on sale in the fall of 1983, its major advance was a very sophisticated spot meter that was able to store and average up to eight readings as well as bias exposure to highlights or shadows depending on the user's preference. This was in addition to the standard centerweighted meter. Other new features (over the OM-2n) were:

• a mechanical backup shutter speed of 1/60 sec
• mirror pre-fire when the self-timer was used
• a built-in diopter adjustment
• an LCD viewfinder display with illuminator
• metered shutter speeds in AUTO mode of 4 min. - 1/2000 sec. with spot metering
• AE lock with 60 min. memory
• an integrated TTL flash hot shoe
• the ISO & EC setting dial was now concentric to the rewind lever

    One long-standing issue with all single-digit OMs had been the rather pedestrian flash sync speed of 1/60 sec. due to the intrinsic limitations of the horizontal travel shutter. With the introduction of the Canon T90 (1986) with its vertical-travel shutter and 1/250 flash sync speed, and Nikon's F4 (1988) on the horizon that would offer the same, Olympus tackled high-speed flash sync. The OM-4 Ti (OM-4 T in the U.S. until 1997) was the result, with titanium top and bottom plates, improved circuits to address the battery drain issues noted in the OM-2S section, and some rudimentary weathersealing (by today's standards ;-)) thrown in for good measure. There were now five contacts on the hot shoe instead of three. A new flash unit was required that offered high-speed sync. capability (albeit at very limited distances; this will be discussed in the flash section of this article). The first OM-4 Ti models came in a champagne finish, with the black finish appearing in the summer of 1989. With the appearance of the titanium enrobed models, the original OM-4's days were numbered; it was discontinued in 1987 and the final stock sold out by the end of 1988. The OM-4 Ti was discontinued in 2002.

    Recommendations. The biggest issue with the OM-2/-2n models is the corrosive foam that de-silvers the pentaprism. If you find a clean one, it is advisable to get the foam cleaned out if it hasn't been already. It will save grief and money down the road. With that taken care of, an OM-2/-2n is our top recommendation for an electronic OM body. Benefits over their successors are: a smoother film advance; longer metered exposure times, particularly with the original OM-2; one of the best viewfinders in all SLRdom with that nice 0.92x magnification; and no battery worries in normal circumstances. Prices are generally a bit more than the OM-2S. As for the OM-2S and OM-4, the battery drain problem will loom larger for some people than others. That is a shame, as both models do have some excellent features:

• The OM-2S has the least shutter vibration and noise of all the OMs (due to the timing needs of the Program mode).

   The OM-2S and the OM-4 also feature:

• spotmetering (with the OM-4 being able to take up to 8 readings and average them)
• mirror pre-fire in the self-timer mode to combat vibration
• integrated hot-shoes that are sturdier than the detachable ones of the OM-2/-2n
• a mechanical backup speed of 1/60 sec. (needed for those beleaguered batteries)  

​    If you are one of those people whose priorities would lead you towards the OM-2S or the OM-4, how can you best manage the battery issue? Some copies seem to be worse than others, so the only way to find out is by trying it out. The first way to combat drain is to only use silver oxide cells instead of the cheaper alkaline LR44s. The alkaline discharge profile exacerbates drain issues because it is constantly decreasing right from new, meaning that such batteries will reach the voltage cutoff of the camera's circuitry more quickly. Silver oxides, on the other hand, have a much flatter curve that stays above the voltage threshold until the very end of their life. Second, removing the batteries anytime the camera is going to sit for longer than a day or two is the only sure way to absolutely prevent drain. Third, develop the habit of making sure the mode switch is not in the battery check position every time you pick up the camera. It is easy to accidentally bump the switch to that position and it will drain the batteries very quickly as it has no provision to self-release from that setting. If this sounds like too much hassle, seriously consider the OM-2/-2n or the OM-4 Ti. Which leads us to...

    ...Value. While this has to be a personal decision based on what your priorities are, here are a few general points when it comes to evaluating the single-digit electronic OMs:

• All three OM-2 models fall into the same average price range from $100 - $150 USD for specimens in excellent condition and sometimes with a lens or two thrown in. Bear in mind the need to have the prism foam cleaned out in the first two models and have the film advance clutch inspected. After that, you should be in the clear. With the OM-2S, the same applies for the film advance clutch and then it's all about the battery situation and what you are willing to put up with. When it has power, the OM-2S is an excellent machine and very capable.
• When it comes to choosing between an OM-2S and the OM-4 one has to determine whether the extra 1/2000 sec. shutter speed, the more sophisticated spot meter (usable in all exposure modes rather than just Manual), and the louder mirror/shutter are worth double the cost. The OM-2S may be considered an OM-4 Lite, but it will lighten your wallet only half as much (more room for the extra batteries that way ;-).
• When comes to the OM-4, the original suffers with the same battery-sucking reputation as the OM-2S. This holds its value to half that of the OM-4 Ti. A very nice OM-4 can be had for $200 - $250 USD and often with a lens or two. The advantages of the Ti over the original are as follows: no abnormal battery drain, high-speed flash sync. (although this is at very limited distances); and titaniummmmm :-). For this you will pay $400 - $500 USD on average for one in excellent to mint condition (a screaming deal next to an OM-3 Ti ;-)). Champagne-colored Tis can look a little ratty once wear takes its toll, which often brings the price down a bit from the black version. 

   Double-Digit Electronic Bodies

    OM-10. 1978 also brought the first consumer-level OM body. The OM-10 was Olympus' reply to the success of Canon's AE-1. Even their TV commercials bore an uncanny resemblance. Olympus cleverly put model Cheryl Tiegs up against Canon's athletes. OM-10s sold well as a result. It was a basic aperture-priority camera, with an add-on "Manual Adapter" for those that wished to shift their own gears. Gone was the familiar shutter speed ring around the lens mount. Flash was non-TTL. The spec sheet was nearly identical to the AE-1, aside from aperture-priority versus the Canon's shutter-priority automation. The only other major difference was the weight...430 grams as opposed to the the relatively pudgy 590 grams of the AE-1. Obviously, being targeted at a mass audience meant that there would be a drop in build quality. The OM-10 was more plasticky, had a louder, harsher mirror/shutter, the controls were less precise in their feel and operation, and reliability was not at the level of a single-digit OM. It also used a smaller viewfinder that showed 93% of the actual frame instead of 97%, did not have interchangeable focusing screens, could use the Winder 2 but not the Motor Drive 1. It did have a more sensitive meter range of -0.5 EV to 18 EV versus the 2 -17 EV of the OM-1n, but was a far cry from an OM-2n. 1980 brought a Quartz data edition, which recorded date information on the film. The OM-10FC appeared sometime later, with the Manual Adapter bundled as standard equipment. Production continued until mid-1983 or so. The OM-10 was mostly sold out by the end of 1984, although they could be found sporadically until 1989. 

    OM-20 (aka OM-G in the U.S.). In 1983, Olympus wanted to establish a greater visual connection between its consumer and enthusiast models. The OM-20 looked much more like an OM-2 than an OM-10. The shutter ring and EC/ISO dial returned. There was now an EC LED in the viewfinder, a PC socket for flash, and a detachable grip. It could also use the Motor Drive 1. The OM-20 really was a replacement for the OM-10, even though they sold alongside one another for about a year. It lasted in the lineup until about mid-1985.

    OM-30 (aka OM-F in the U.S.). Introduced alongside the OM-20, the OM-30 was very similar, aside from being Olympus' first attempt at an auto focus SLR (with one dedicated 35-70mm lens). With standard OM lenses it was full manual focus with an electronic focusing aid. It required 5 - 357/S76/SR44 cells and these were housed behind a door on the right side of the lens mount. The PC socket and EC LED were deleted, the EC dial simplified, the shutter release was now a semi-rectangular shape, and there had been a slight restyling of the top and bottom plates. As with all of its electronic focus aid-equipped/rudimentary auto focus competitors, the OM-30 was short-lived. By early summer in 1984, it was disappearing from dealers' listings, and its place was taken by the manual focus-only OM-40.  

    OM-40 (aka OM-PC in the U.S.). The Nikon FA introduced multi-segment metering to SLRs in late 1983. It used a five-segment meter that compared its readings to a database of 30,000 exposures stored in its memory and then determined what it felt was the best exposure. Olympus had been heavily promoting spotmetering in its advanced SLRs at the same time, believing that pros and advanced amateurs would be better served by making their own decisions about exposure. With the consumer-aimed OM-40, Olympus took the basic metering module of the OM-2S, with its separate centerweighted and spotmeter capabilities, and came up with ESP (electro-selective-pattern) metering. That was a fancy way of saying that when the camera encountered a complex lighting situation (such as extreme backlighting) it would combine a centerweighted and spot reading, give priority to the reading from the center of the frame, and then made the exposure. When in ESP mode, the camera makes the choice of whether to take a standard centerweighted reading or engage ESP. The user could also choose standard centerweighted metering at any time via a switch on the upper left side of the lens mount. Other features separating the OM-40 from its predecessors were: the inclusion of TTL flash (a first for a consumer level Olympus), a top ISO speed of 3200, and automatic DX film speed setting that could be overridden manually (my preference). It also followed the newer single-digit OMs in using the Motor Drive 2. As stated above, the OM-40 replaced the OM-30 at the same price point and was more successful saleswise. Because the OM-40 used the same Program mode as the OM-2S, it was also limited to a maximum frame rate of 3.5 fps with the Motor Drive. It was discontinued in 1987 but was readily available until the spring of 1988.  

    OM77AF & OM88 (aka OM-707 & OM-101 outside the U.S.). These two abominations hardly merit mention in this article, aside from a warning to stay away. They had their own (paltry) set of lenses and had very limited compatibility with the regular OM accessories. The OM77AF was the worst SLR Olympus ever made: it was heavy, bulky, gimmicky, notoriously unreliable - in other words, the antithesis of the original OM philosophy. The OM88 ditched auto focus for power focusing (more gimmicks). It had a better grip and a more integrated layout than the OM77AF, but lacked any standard manual controls. In a flashback to the OM-10, Olympus provided an optional Manual Adapter 2, which provided both aperture and shutter speed controls. It was a rather tacked on design, which did not fit with the rest of the camera. Both cameras did use the OM mount, and it is possible to mount some (but not all) manual focus OM lenses on them. What would possess a person to do so is another matter (perhaps subterranean reserves of abject hatred for OM lenses not to mention oneself ;-)). Not recommended is all that needs to be said. Mercifully, Olympus killed their auto and power focus project after only a few years. 

    Recommendations. Why would you consider a double-digit OM instead of a single-digit? The number one reason, as usual...cost. Now it is still true, "you get what you pay for". There is no arguing the build quality difference between pro and consumer cameras. If you have the means to get a good single-digit body, you will likely not be disappointed. But what if they are out of your financial reach? Is a double-digit OM going to consign you to the depths of photographic misery because of its cheaper build and feel? Not necessarily. A cheap photographic experience is better than none at all, and can even be liberating as you are not constantly worrying about damaging your precious one. You can often find OM-10s, -20s, or 40s for a few dollars on a thrift store shelf or at a garage sale. Or excellent working copies can be had for $60 - $80 USD online or from dealers. Of course, there is some risk in buying a 30 + year old piece of electronics. Be aware that the shutter release electromagnets on these models often become oil-fouled and will stick together. Such a camera will often have the mirror stuck in the up position. A simple cleaning of the magnets and fresh batteries will usually (but not always) set things to rights. Consider yourself warned :-).

    Oh, and on the subject of batteries, the good old drain issue just backed up again. The OM-40...or OM-2S Lite in this context...can suffer the same malady as its big brother (it seems, in my limited experience, that high serial# OM-40 or OM-PC bodies have no drainage issues). Its double-digit predecessors do not. Otherwise, it is the most fully-featured double-digit OM body Olympus made. The TTL flash metering and the ESP metering do work very well, if you need them. If the battery issues bother you, take a good look at an OM-20. It (along with the OM-40) has the closest control layout to the single-digit OMs, for an easier time with muscle memory (if you want it for a backup) and all that, plus the best reliability of the -10, -20, -30, -40 family. The bonus being that it can be had for the same or less as an OM-10. The OM-10 had some serious reliability issues in its first year that eventually got ironed out, and the OM-20 was the beneficiary of such learning experiences at Olympus. If you just can't live without an OM-10, make sure it has the Manual Adapter. The adapters cost as much used now as they did new, but you can get them with a body for nothing. If you can find an OM-10FC for a reasonable price, it should be the most reliable of the various OM-10 iterations, as it was a late-production version with the Manual Adapter included. The FC logo is printed on the shutter speed dial instead of "MANUAL ADAPTER". They are not terribly common, but they are out there. The OM-30 is rather like a de-contented OM-20, besides the electronic focus aid, and is viewed as something of a collectors item due to its relative rarity and historical significance. So prices can be quite high. While not the belaborer of batteries that the OM-40 can be, it still consumes them in large bites, five at a time compared to the two-bite-size OM-10, -20 ,and -40. Let's just say that Olympus and auto focus, when it came to the original OM system, were just not meant to be. Can you get good results if you find one for cheap? Absolutely, as you can with any of these models. 

  Flash

     Now we come to an Olympian paradox - flash. In most ways they were so far ahead of the competition, it wasn't even a contest, yet one decision would restrict them from having the ultimate in flash capability. Olympus was the first company to build SLRs with TTL flash metering and not just TTL, but measured directly off the film (OTF), the most accurate method. The entire Olympus flash system is probably the best integrated and simple to understand of all the vintage systems. One quirk of the OM flash system was the decision of Olympus to use a detachable hot shoe on the OM-1 through OM-2n models. There were eventually four different shoes produced to provide compatibility with newer flash units. Here is a brief rundown of capability/compatibility:

1. Shoe 1 - Although not labelled as such, this was the first basic hot shoe adapter introduced with the OM-1. It has a single contact for X-sync. It has the word FIX on the back with an arrow indicating the direction to turn the locking nut that secured the shoe to the prism housing. It can only be used on OM-1(n) & -2(n) bodies for manual or auto flash. It has NO TTL capability.
2. Shoe 2 - This was the original TTL-capable shoe for the OM-2 and QA310 flash unit. The smaller TTL contact is directly in front of the X-sync contact. The OM-2 had a small hole behind the threaded coupler that the TTL contact on the Shoe 2 penetrated to make contact inside the prism housing. Thus Shoe 2 can ONLY be used on an OM-2. Attempting to mount it on any other OM body with result in damage. It has "SHOE 2" above "FIX" on the rear label.
3. Shoe 3 - This was the second TTL-capable shoe for the OM-2. It adopted the new contact pin configuration of the T-series flash units. The QA310 cannot be used in TTL mode with Shoe 3 on the OM-2. Again, Shoe 3 is ONLY for the OM-2 and will invoke damage if attempts are made to mount it on any other OM body. It has "SHOE 3" above the word "LOCK" on the rear label.
4. Shoe 4 - This was the final shoe configuration, and was used on both the OM-1n and -2n bodies. There were now three contacts (the third one for a viewfinder flash signal). There were now two small holes at the back of the prism housing for the TTL and viewfinder signal contacts of Shoe 4 to penetrate into the housing. "SHOE 4" was printed on the back of the prism housings of both bodies to prevent the mounting of the older hot shoe adapters. Only the OM-2n utilized the TTL contact of Shoe 4, the OM-1n was not TTL-capable. Shoe 4 can ONLY be used on those two bodies. It is labelled "SHOE 4" over "LOCK".

• PS200 & PS200 Quick - These were basic, small, manual flashes originally designed for the Olympus Trip and Pen models. They can be used on any OM body. The Quick uses 4 - AAs to the PS200s two, and is the preferred model because of its faster recycling. Guide Number for both is 14 (meters @ ISO 100).

• ​Quick Auto 300 - This was the first flash introduced with the OM-1, and was more advanced and powerful than any of its competitors at the time. It was not TTL capable. There were three auto sensor settings and two (full & 1/4) power ranges. It had a guide number (GN) of 34 meters @ ISO 100. It used thyristor (power-saving) circuitry and only required four AA cells on its own. It was the central part of a modular flash system. Olympus offered a Power Bounce Grip (PBG) and bracket to allow articulation of the whole flash head, a cable to connect it to the camera, a Remote Sensor (to control the flash duration), and a detachable hot shoe (Shoe 1) that the Remote Sensor & cable connected to. The PBG-1 used four "C" batteries (264 grams/9.3 oz) to provide faster recycling and more endurance for professional applications. The full rig with batteries, came in at 975 grams (34.3 oz). For a comparison, check out the contemporaneous Nikon SB-5: 900 grams (31.8 oz), without batteries and without the mounting bracket. Not to mention that the separate Nikon battery packs consisted of 6 - "D" cells (864 grams/30.5 oz). Which would you rather pack around? :-)

• Quick Auto 310 - The QA300 only lasted for a couple of years on the market. Why? because it was replaced by the first TTL flash ever produced, the QA310. Specs were identical aside from that. It was introduced with the OM-2 and a new detachable hot shoe (Shoe 2).

    The next step for OM flash came with the debut of the OM-2n in 1978. A new contact configuration for the flash foot with a third pin for viewfinder flash confirmation was introduced. Olympus also took the opportunity to introduce the T-series of flash units that would last to the end of OM production. This required a new series of hot shoes (Shoe 3 for use with OM-2 & Shoe 4 for all bodies from the OM-2n onward). 

• T20 - The first of the T-series to debut was this basic flash that combined compact dimensions with a weight of just 200 grams (7 oz) with its two AA batteries in place. As its designation suggested, the GN was 20. It had one power setting (full), two auto settings for non-TTL auto flash, and full TTL capabilities. The T20 had coverage for a 35mm lens without the detachable wide angle diffuser that increased coverage to cover the 28mm focal length. It had no bounce capability of its own, but it was fully compatible with the new Power Bounce Grip 2 and the rest of the OM Flash system. It would retain its position in the lineup until the end of OM production in 2002.

• T32 - This workhorse of the T-series was the successor to the QA310. It had a slightly reduced GN of 32, and retained the two power settings and three auto sensor settings of its predecessor, besides TTL. A handy new feature was a pivoting flash head with seven click-stop settings between -15 to 90 degrees for bounce flash, meaning that the PBG-2 was not needed for basic bounce flash. That meant a major reduction in bulk and weight for enthusiasts who did not need the added capability or weight of the PBG-2. The T32 was a nice compromise for many users and stayed in production until the end of the OM line.

• T45 - For pros that needed more horsepower, Olympus had them covered with the T45, the most powerful OEM flash then in production. Debuting with the OM-4 in 1983, it was meant for serious work and not for snapshooting. It came with its own Ni-cad battery pack and charger, integrated grip and bracket to mount an OM- body to. While it retained the three auto sensor settings of the T32, it took OM manual flash to a whole new level with six power levels (from full to 1/32 power). The flash with its integrated grip and camera mounting bracket sold for $190 USD ($430 USD in 2017), and the battery pack and charger for $88 USD ($200 USD in 2017) in 1985. For comparison's sake, the T32 was $75 USD ($170 USD in 2017), almost 1/4 of the cost. The T45 lasted until 1992, which is not surprising as many pros were beginning to move towards auto focus, and Olympus, unfortunately, could not meet their needs.

• T18 - The T18 was introduced in the late-'80s with the OM77 AF & OM88 cameras as a bare-bones TTL-only flash with a GN of 18. There is not much documentation about it to be found online.

• F280 - Just to throw a curve at us, the final flash model Olympus made for the OM system dropped the T-designation for an "F". This was the final innovation in the OM Flashgroup. While lens shutters have no problem with flash synchronization at all speeds, with the focal-plane shutters that were used in most SLRs (including Olympus') there were intrinsic limitations as to flash use at higher shutter speeds. The one area Olympus was beginning to fall behind the other manufacturers in, related, not to the flash units themselves, but rather the shutter configuration of most of the the OM cameras. Olympus doggedly stuck with the proven horizontal-travel shutter (with a top flash sync. speed of 1/60 sec.) until the introduction of the otherwise less-than inspiring OM77 & 88 models (their vertical shutter allowed for a 1/125 sync speed). Olympus thus tried to find a way to achieve high-speed sync. with its standard shutters. The F280 was the result. It was the first flash to synchronize at all shutter speeds with a focal-plane shutter. It did so by pulsing the flash at such short durations that the light would fall evenly across the whole frame during the exposure. It was an amazing achievement that would soon be copied by Olympus' competitors. But there was a catch, pulsing the flash at such short intervals could only be accomplished at a very reduced power setting, otherwise the flash would overheat in short order. This issue is still present in the latest high-speed flashes today. The result was that high-speed sync. flash only worked at very short distances; i.e. at 1/2000 sec. & f2.8 @ISO 400, the maximum subject distance was 1.6m (5.3 feet). Even at the 1/250 sync. speeds that the other manufacturers achieved by the late-'80s, the F280 and an OM-4 Ti would top out at a distance of 5m (16.4 feet), while the competition could use full power at that shutter speed. The F280 was also the first Olympus flash to use a near-infrared AF assist lamp for use with the OM 77AF. It had a GN of 28 at full power and no bounce capability of its own (it could be used with the PBG 2). 
• S20 - This was the tiny companion flash for the OM2000. Introduced in 1997, it was like a modern PS200 with the addition of two auto settings to go with full manual flash. The GN was 20. Standard coverage is for a 35mm lens, but the optional wide diffuser extends that to coverage for a 24mm lens with a GN of 14. It is a great little flash than can go almost anywhere in a gear bag. S20s are quite rare and can suffer from inflated prices as a result. However, the newer digital FL-20 flash is basically an updated S20 that also offers TTL with Olympus digital cameras while still having an auto setting along with full manual for use on film OMs (but no TTL with film OMs). FL-20s can often be had for half the price of an S20 and are much more common. 

   Macro Flash Units

• T10 Ring Flash 1 - The first TTL macro flash in the world was introduced in 1980 and stayed in production for an amazing 22 years. The T Power Control unit was required for the T10, and any other OM macro flash to function. The T10 had a GN of 10 (imagine that) and had 8 small modelling lights integrated into the ring to allow previewing and assist focusing. 
• T8 Ring Flash 2 - The second TTL macro ring flash made by Olympus debuted in early summer 1984. It was slight less powerful than the T10 with GN of 8, but featured two diffuser rings (150mm & 200mm diameter) that it fired sideways (instead of forward like the T10) into to provide soft shadowless lighting. It retained the modelling lights of the T10.
• T28 Macro Flash - This flash also debuted in 1984 with the T8, but took a different approach. It could be used in a single or twin configuration with a ring adapter that the rectangular unit(s) mounted to. It was far more powerful than the ring flashes, having a GN of 28 in single and a GN of 22 in twin layout. The T28 was designed for greater working distances than the ring flash units. 

    Recommendations. If you need bounce flash and/or big power, the T32 will cover all the bases. It was the most compact and lightest-weight flash in its power class and can be easily obtained for $50 USD or less. Sometimes you can pick one up in combination with a body or kit for basically nothing. If bounce capability is not important and you can get by with less power, the T20 is hard to beat. There are loads of them that come with bodies or kits and they only need 2 AAs. Purchased separately, they run about $25 USD or so. One important thing to remember with both of these T-series flashes: check to make sure that the rear slip-in panel which flips to provide manual calculations and auto settings is in place. Many times they have been lost or otherwise removed. Prices for the panels themselves are quite high. Both the T20/T32 require the use of Shoe 3 on the OM-2 and Shoe 4 on the OM-1n & -2n for TTL function. Something to keep in mind about all of the detachable shoes is that they will develop diagonal cracks in their top corners when they are over-tightened or when a flash unit is pushed on while the shoe is unsupported. It is rare to find a used shoe that has not succumbed to such treatment. Some epoxy and gentle treatment in the future will extend the life of an ailing detachable shoe :-).   

  The T32 is to be preferred to the QA310 as it offers bounce capability and full compatibility with any TTL OM body. The QA310 only offers TTL with the OM-2 and Shoe 2; with any other OM body, you are left with auto or manual flash. If you found an OM-2 with a QA310 and Shoe 2 included, it's probably not worth getting a T32 and Shoe 3 unless your really need/want the bounce capability of the T32. QA310s go for $35 USD on average.

    Olympus had the best selection of Macro flash units of any of the Japanese camera companies. One excellent feature was that they all used the same T Power Control Unit and you could buy the different flash units separately. The same reminder to ensure that the manual calculator panel is in place as on the other T-series flashes applies to the T Power Control. The standard panel was for the use with the 50mm macro lens, with optional accessory panels for the other OM macro lenses. Price are even crazier for these macro panels than the standard T-flash panels, so it is wise to check out the availability and pricing of the specific panel/lens combination you are considering. As far as selecting among the different flash units, if you use longer lenses with greater working distances, the T28 offers the most power and flexibility with the ability to use it in a single or double-head configuration. This versatility is reflected in pricing that ranges from $65 to $280 USD for the bare double-lamp setup to the full system with mounting ring for both flash heads. The T10 was the most common & basic OM Macro ring flash and prices run from $40 to $110 USD, sometimes with the T Power Control Unit included. The T8, with its diffuser discs, offered even softer lighting than the T10, and was designed for closer working distances than the T28. It is the rarest of the three, particularly with a complete set of diffusers. Prices tend to start at the high end of the T10 range and go up from there. Such are the capabilities of the T10 and T8 units that some enterprising Olympians have managed to adapt them for use with the Olympus micro-4/3s system (some DIY soldering skills required :-)).

 
  Accessories

​    From the start, the OM was intended to be a full system, with a wide range of accessories to provide the versatility demanded by professionals. Here is a brief overview of the OM accessory lineup.

     Focusing Screens & Finders. There were 13 different interchangeable focusing screens available at the time of the introduction of the OM-1. Three more were added as time went by:

1. 1-1. Microprism-matte type (for most lenses). Central microprism focusing aid surrounded by a matte field. Microprism darkens at f/5.6 aperture or smaller, requiring use of matte field for focusing.
2. 1-2. Microprism-matte type (for standard/telephoto lenses). Same as 1-1, except microprism is usable to f/8 instead of f/5.6. 
3. 1-3. Split image-matte type (for most lenses). Central split-image focusing aid surrounded by a matte field. Split image darkens at f/5.6 aperture or smaller, requiring use of matte field for focusing.
4. 1-4. All matte type (for most lenses). No central focusing aids for those photographers that prefer a plain field. Suitable for super telephoto lenses and macrophotography.
5. 1-5; 1-6; 1-7. Microprism-clear field type. Central microprism focusing aid, surrounded by a bright, clear field that does not show depth-of-field effects. Meter does not show the correct exposure because of the lack of a matte field. The 1-5 is for wide angle/standard lenses, the 1-6 for standard/telephoto lenses, and the 1-7 for super telephotos. The microprisms black out at f/5.6, f/8, and f/11, respectively.
6. 1-8. All matte type (for telephotos and astronomical telescopes) No central focusing aids. The matte field is finer-grained than that of the 1-4 screen, to provide more accurate focusing with extremely long lenses. Can be used in conjunction with the Varimagni finder for maximum focusing accuracy.
7. 1-9. Clear field type (for use with endoscopes). Condenser type screen with no fresnel lens. Very specialized for medical use.
8. 1-10. Checker-matte type. Grid of horizontal and vertical lines engraved as a recticle on a matte field. Originally designed for architectural photography with shift lenses. Actually very versatile, can be used to level horizons in landscapes, provide alignment in macrophotography, and with super telephotos. 
9. 1-11. Cross hairs-matte field type (for close-up and macrophotography). Especially advantageous for use with extension tubes and bellows. Matte field is used for low-magnification close-up focusing, while central double cross hair is for greater than life size macrophotography. Meter shows correct exposure, but specimen condition sometimes requires an exposure adjustment.
10. 1-12. Cross hairs-clear field type (for microphotography and greater than life size macrophotography). Brighter than 1-11 screen because of clear field. Meter does shows correct exposure, but specimen condition sometimes requires an exposure adjustment. Diopter must be corrected by a dioptric corrective lens or the Varimagni finder before focusing double cross hairs and moving the specimen to the correct focus.
11. 1-13. Microprism/split image-matte type (for most lenses). The standard screen for the single-digit OM SLRs. Central split image rangefinder with microprism collar surrounded by a matte field . As with the 1-1 & 1-3 screens, when the central aids darken at f/5.6, focusing must be done with the matte field. 
12. 1-14. Microprism/split image-matte type (for most lenses). Identical to 1-13, aside from 45 degree diagonal split image rangefinder focusing aid.
13. 2-4. All matte type. This is a brighter version of the 1-4 screen for use in the OM-2S/Spot Program, OM-3/Ti, and OM-4/T/Ti. It cannot be used with the OM-1/-1n or the OM-2/-2n. There is a circle that indicates the spot metering area. This screen was designed for lenses with an maximum aperture of f/4 or faster.
14. 2-13. Microprism/split image-matte type. A brighter version of the 1-13, again limited to the OM-2S/Spot Program and higher-numbered single-digit OMs. The central aids darken at f/5.6 as with the 1-13.

   The Varimagni angle finder combined two available levels of magnification (1.2x overall and 2.5X in the center of the viewfinder) for critical focusing in macro & microphotography as well as astrophotography. An Eyecoupler was needed to use the Varimagni in microphotography. There was also the rubber Eyecup 1 which was compatible with a range of eight dioptric correction (from -5 to +2 diopters) eyepieces. 

    Motor Drives/Winders. It took Olympus a couple of years to configure the OM-1 for motor drive capability. It was worth the wait, as they came up with a highly modular system that was lighter and more compact than those of their competitors. There was a base motor drive unit, with two available DC power units (the M. 18V Control Grip 1 & the M. 15V Ni-Cd Control Pack 1), and the corded M. AC Control Box (up to 4 fps) that were used for motor drives. Here is the breakdown:

• Motor Drive 1 - This was a revelation as far as motor drives went in the mid '70s. It could achieve up to 5 fps without MLU. And at a total weight of 470 grams (16.6 oz) with the M. 15V Ni-Cd Control Pack 1. Compare that to the Nikon MD-2 Motor Drive (470 grams bare) with the MB-1 battery pack with two MN-1 Ni-cad battery units (480 grams). And the Nikon drive could only do 5 fps with the mirror locked up. All the performance at half the weight :-). There is obviously more to the matter than just weight and speed, but this serves to illustrate that Olympus was serious about motor drive performance.
• Winder 1 - This was a basic winder that offered powered single-frame advance. It did have a nice hand grip, which most competitors did not include with their winders. It used 4 AAs for power.
• Winder 2 - Introduced in 1980, the Winder 2 added sequential advance with 2.5 fps along with the existing single-shot mode of the Winder 1. It was completely backward compatible with all OM bodies. It was not compatible with the internal winder-equipped OMs or the OM2000.
• Motor Drive 2 - An updated Motor drive 1 that was fully backward compatible with the older single-digit OMs, but offered several new features when used with the OM-3/4 and newer bodies. It added an LCD display with a frames remaining counter, and wind and rewind indicators. With the newer bodies there was powered rewinding available and there was now some weathersealing. In true Olympian fashion, weight was reduced to 360 grams. The same battery packs were used. 

   Miscellaneous. Olympus had a range of Recordata backs for date, time, or count imprinting. There were 4 versions: the first two were analog and the final two were digital. All of them are obsolete as far as dates are concerned but can be used for frame counts and some can imprint the time. There were also a variety of telescope and microscope adapters. Many of these accessories are very rare nowadays.

  Reliability and Servicing

    As noted earlier, in North America the service supplier of choice is John Hermanson @ Camtech. There are still some other independent repair shops, but I cannot vouch specifically for them. OM-1s should have CLAs occasionally as with any mechanical SLR of any brand for best operation. Having the prism foam removed on OM-1(n) & OM-2(n) models should be considered mandatory to extend their life as far as possible. For electronic OM's and accessories, there are very few to no circuits available, so you takes your chances. The single-digit OMs were built to a higher standard than the double-digits, but both can provide years of trouble-free service. Aside from the battery-drain issues that affect some OM-2S/-4/-40 bodies, electronic Olympii in general are as reliable as any of the other Big 5 makers' models. OM lenses do have a tendency for the helical grease to separate and the oil will sometimes foul the aperture blades. This can be cleaned fairly easily in most situations. The flash couplers are a bit of a weak point on the OM-1/2 models, but are workable when care is taken. Overall, there is not much to worry about with the Olympus OM system.

  Conclusion

    Olympus was easily one of the most innovative and influential members of the Big 5. They started out aiming at professionals and enthusiasts and then moved into the consumer market later on. This was a similar approach to that of Nikon. They were never a sales leader, but the OM system was very full-featured and in the areas of macro and microphotography they were the leader. If light weight and compact design are high on your list, take a very long look at the OM family. 

  References:

    Photography in Malaysia - Olympus OM-1(n), OM-2(n), and Zuiko Lenses
    Olympus Manuals @ http://www.butkus.org/chinon/index.html