Olympus OM system
The Olympus OM System (O = Olympus, M = Maitani) was a line of 35mm single-lens reflex cameras, lenses and accessories sold by Olympus between 1972 and 2002 (some accessories were sold through early 2003).
The system was introduced by Olympus in 1972, more than a decade after Nikon, Canon, and other manufacturers had established their own SLR ranges. The range was designed by Yoshihisa Maitani, chief designer for Olympus, and his staff. The nucleus of the system was a series of compact bodies divided into a professional series and a later consumer-orientated series. The first model introduced was the all-mechanical M-1, which after pressure from Leica was renamed OM-1. The body included a full aperture TTL CdS exposure meter and a bayonet lens mount of relatively large diameter. By the end of the 1970s it was joined by the semi automatic OM-2 and consumer oriented OM-10. Olympus continued the naming pattern with the professional OM-3 and OM-4, and the consumer-level OM-20, OM-30, and OM-40. The system was accompanied by a series of Zuiko-branded lenses, as well as a generous selection of accessories. The majority of OM bodies and lenses were manual focus only; the OM-707 of 1986 was the only true autofocus model.
 Camera models
Olympus produced a wide variety of OM camera models over the years. These were divided into two distinct series. Cameras with single-digit model numbers were the professional series, optimized for features and ruggedness rather than ease of use. Two-digit (or more) model numbers, or letters, meant a consumer camera designed for ease of use.
All the consumer-grade models were discontinued after 1992, since the market for manual focus cameras in this segment had dried up. The consumer-grade line returned in 1997 with the Cosina-sourced OM-2000 model. Professional and advanced amateur demand for the high-end models continued, and they were produced until 2002 along with the consumer-grade OM-2000.
 Professional cameras
The Olympus OM-1 is a manually operated 35 mm single-lens reflex camera forming the ground of the OM system introduced in 1972, at first called the Olympus M-1, Leica disputed this designation and it was changed to OM. It was designed by a team led by the late Yoshihisa Maitani with a through-the-lens exposure meter controlling a needle visible in the viewfinder. It was noted for its reduction of size, weight and noise. These features were essentially retained on later models. One feature unique to the OM1 compared to the rest of the OM system was its manual mirror lock-up making it ideal for astrophotography and macrophotography.
Introduced in 1975, the Olympus OM-2 was a semi automatic, aperture priority camera based on the OM-1 body, retaining compatibility with accessories and lenses. It boasts automatic through-the-lens (TTL) off-the-film (OTF) metering: exposure was considered very accurate, calculated by the measured light reflected off the surface of the shutter and/or the film surface during the actual exposure. The camera also offered a manual light-meter mode, as in the OM-1. It also introduces the integration of electronic flash into the exposure system via the same TTL exposure system.
The OM-3 was an updated version of the OM-1, a manual camera without automatic exposure modes, and an entirely mechanical shutter. It featured a multi-spot metering system (which it shared with the OM-4) in addition to the centre weighted metering on the earlier body. It also featured an LCD display similar to the OM-4 which could be illuminated in low light. Its main advantage over the OM-4 was its ability to operate without batteries due to its mechanical nature. Batteries were only needed for the multi spot meter and LCD display. It lacked a self-timer however.
In 1995, nine years after the OM-3 was discontinued, the OM-3Ti was released. It shared the improvements over the OM-3 that the OM-4Ti held over the OM-4.
The Olympus OM-4, an improved version of the OM-2, was manufactured from 1983 to 1987 introduced at US$685 list price for the body alone. It was a battery powered electromechanically controlled manual focus SLR with manual exposure control or aperture priority autoexposure. It used a horizontal cloth focal plane shutter with a speed range of 240 to 1/2000th second plus bulb and flash X-sync of 1/60th second.
It was the first camera with a built-in spot meter[of a narrow angle, see Canon FTb](2% of view; 3.3˚ with 50 mm lens) and could measure nine individual spots and average them. The light meter used a dual concentric segmented silicon photo diode to provide spot or centerweighted readings. It used a graduated linear LCD display for the shutter speed at the bottom of the viewfinder to precisely indicate its readings versus the actual camera settings instead of a needle.
In 1986 it was improved to a tougher OM-4Ti (OM-4T in USA) version, with titanium top and bottom plates, improved weatherproofing and high-speed sync with the flash staying on during the entire shutter operation, losing the light hidden by the curtains. This last version was finally discontinued in 2002.
 Consumer-grade cameras
The OM-10 hit the markets in June 1979 at the same time as the OM-2N. The camera is a 35mm focal-plane shutter aperture priority AE SLR camera with an electronic shutter. Only aperture priority AE was available with the camera unless the optional manual exposure adapter was installed which allowed the setting of shutters speeds between 1 second and 1/1000 of a second (bulb mode is also available on the camera). The camera is equipped with a fixed pentaprism viewfinder which contains an LED exposure indicator. The finder coverage was measured to be 93%.
Exposure control is based on aperture priority AE or center-weighted light metering. Film speeds of the camera range from ASA 25 to ASA 1600. Film winding is done by using the film wind lever located on the top right of the camera. Film rewinding is done manually using the film rewind crank located above the film canister on the top left of the camera. The camera body measures 136 × 83 × 50 mm and weighs approximately 430 grams (15 oz).
The OM-20 (sold in the United States as the OM-G) was essentially a refinement of the OM-10, replacing that model's rather tricky mode switch with one that was easier to use. The OM-20 also had a built-in shutter speed dial and a mode display in the view finder as well as a few more minor design improvements.
Essentially an OM-20 with auto-focus capability. With a normal lens there are lights in the view finder to help aid the user with focusing, a special autofocus lens was also available at the time but is now very rare.
A further refinement of the OM-20 with features that are more of interest to most serious photographers. It has a lighter slightly more modern and ergonomic body design. It also had an early form of Matrix metering and full mirror lock-up when the self-timer is switched on, a feature still rarely found in non-high end cameras.
Also known in some markets as the OM-PC, the OM-40 had a program mode that automated the selection of both the aperture and the shutter speed.
Essentially a Cosina-made SLR with an Olympus badge, not considered by Olympus "die-hard fans" to be a true OM camera.
The OM-2000 has a mechanical vertical shutter as opposed to the traditional OM cameras with their horizontal shutter. This allows the OM-2000 to synchronize an electronic flash at 1/125th of a second. Many photographers find this capability an advantage for the use of "fill flash" techniques in daylight.
 Prototype cameras
During the design study of the OM-1, the Olympus design team led by Yoshihisa Maitani had worked on a completely modular camera, like a 35 mm Hasselblad. This camera was built as a prototype, and was called the OM-X.
The OM Series lenses have the aperture control located on the lens barrel on the opposite side of the focusing ring from the mount. This was done to move it away from the shutter speed control, which is a ring on the camera body immediately behind the lens mount. They also feature a depth of field preview button on the lens itself, as opposed to most other SLR camera systems in which the button is placed on the camera body.
The OM lens is designed to sit 46 mm (as measured from the front of the aluminium ring on which the serial number is stamped) from the film onto which it projects, further away than many other lens systems. The combination of on-lens aperture control and this extra distance make OM lenses adaptable with full (manual) functionality to a variety of other camera systems – including the ubiquitous Canon EOS line – by using a specialized adapter.
|Lens||Angle of view||Elements – Groups||Diaphragm||Aperture range||Closest focus||Smallest field||Focusing||Weight||Length||Diameter||Hood||Filter|
|8 mm F2.8 Fisheye||180° (circle)||11–7||Auto||2.8–22||0.2 m||-||Straight helicoid||640 g||82 mm||102 mm||Not necessary||Built-in (L39,Y48, O56,R60)|
|16 mm F3.5 Fisheye||180°||11–8||Auto||3.5–22||0.2 m||-||Straight helicoid||180 g||31 mm||59 mm||Not necessary||Built-in
|18 mm F3.5||100°||11–9||Auto||3.5–16||0.25 m||30×20 cm||Straight helicoid||250 g||42 mm||62 mm||49 mm Adapter Ring 49→72||72 mm Screw-in (w.Adapter Ring 49→72)|
|21 mm F2||92°||11–9||Auto||2–16||0.2 m||21×14 cm||Straight helicoid||250 g||43.5 mm||60 mm||55 mm Screw-in [57 mm Slide-on]||55 mm Screw-in|
|21 mm F3.5||92°||7–7||Auto||3.5–16||0.2 m||21×14 cm||Straight helicoid||180 g||31 mm||59 mm||49 mm Screw-in||49 mm Screw-in|
|24 mm F2||84°||10–8||Auto||2–16||0.25 m||23×15 cm||Straight helicoid||280 g||48 mm||60 mm||55 mm Screw-in||55 mm Screw-in|
|24 mm F2.8||84°||8–7||Auto||2.8–16||0.25 m||23×15 cm||Straight helicoid||180 g||31 m||59 mm||49 mm Screw-in||49 mm Screw-in|
|24 mm F3.5 Shift||84° (100° at max. shift)||12-10||Manual||3.5–22||0.35 m||36×24 cm||Rotating cam(Inner focus)||510 g||75 mm||84 mm||Fixed||Built-in (neutral, Y48,O56, R60)|
|28 mm F2||75°||9–8||Auto||2–16||0.3 m||27×18 cm||Straight helicoid||250 g||43 mm||60 mm||49 mm Screw-in||49 mm Screw-in|
|28 mm F2.8||75°||6–6||Auto||2.8–22||0.3 m||18×27 cm||Straight helicoid||170 g||32 mm||60 mm||49 mm Screw-in||49 mm Screw-in|
|28 mm F3.5||75°||7–7||Auto||3.5–16||0.3 m||18×27 cm||Straight helicoid||180 g||31 mm||59 mm||49 mm Screw-in||49 mm Screw-in|
|35 mm F2||63°||8–7||Auto||2–16||0.3 m||21×14 cm||Straight helicoid||240 g||42 mm||60 mm||55 mm Screw-in||55 mm Screw-in|
|35 mm F2.8||63°||7–6||Auto||2.8–16||0.3 m||21×14 cm||Straight helicoid||180 g||33 mm||59 mm||51 mm Slide-on||49 mm Screw-in|
|35 mm F2.8 Shift||63° (83° at max. shift)||8–7||Manual||2.8–22||0.3 m||21×14 cm||Straigh helicoid||310 g||58 mm||68 mm||49 mm Screw-in||49 mm Screw-in|
|40 mm F2||56°||6–6||Auto||2–16||0.3 m||18×12 cm||Straight helicoid||140 g||25 mm||60 mm||49 mm Screw-in||49 mm
|50 mm F1.2||47°||7–6||Auto||1.2–16||0.45 m||24×16 cm||Straight helicoid||285 g||43 mm||65 mm||51 mm Slide-on||49 mm Screw-in|
|50 mm F1.4||47°||7–6||Auto||1.4–16||0.45 m||24×16 cm||Straight helicoid||230 g||36 mm [40 mm]||60 mm||51 mm Slide-on||49 mm Screw-in|
|50 mm F1.8||47°||6–5
|Auto||1.8–16||0.45 m||24×16 cm||Straight helicoid||170 g [165 g]||31 mm [32 mm]||59 mm [61 mm]||51 mm Slide-on||49 mm Screw-in|
|50 mm F2Macro||47°||9–7||Auto||2–16||0.24 m||7.2×4.8 cm||Straight helicoid||320 g||55 mm||69 mm||Not necessary||55 mm Screw-in|
|50 mm F3.5Macro||47°||5–4||Auto||3.5–22||0.23 m||7.2×4.8 cm||Straight helicoid||200 g||40 mm||60 mm||Not necessary||49 mm Screw-in|
|55 mm F1.2||43°||7–6||Auto||1.2–16||0.45 m||23×15 cm||Straight helicoid||310 g||47 mm||65 mm||57 mm Slide-on||55 mm Screw-in|
|85 mm F2||29°||6–4
|Auto||2–16||0.85 m||25×17 cm||Straight helicoid||260 g||46 mm||60 mm||49 mm Screw-in||49 mm Screw-in|
|90 mm F2Macro||27°||9–9||Auto||2–22||0.4 m||7.2×4.8 cm||Straight helicoid||550 g||71 mm||72 mm||57 mm Slide-on||55 mm Screw-in|
|100 mm F2||24°||7–6||Auto||2–22||0.7 m||18×12 cm||Straight helicoid||520 g||72 mm||70 mm||Built-in||55 mm Screw-in|
|100 mm F2.8||24°||5–5||Auto||2.8–22||1m||29×19 cm||Straight helicoid||230 g||48 mm||60 mm||49 mm Screw-in||49 mm Screw-in|
|135 mm F2.8||18°||5–5||Auto||2.8–22||1.5 m||32×21 cm||Straight helicoid||360 g||80 mm||61 mm||Built-in||55 mm Screw-in|
|135 mm F3.5||18°||5–4||Auto||3.5–22||1.5 m||32×21 cm||Straight helicoid||290 g||73 mm||60 mm||Built-in||49 mm Screw-in|
|180 mm F2||14°||10–8||Auto||2–22||1.6 m||25×17 cm||Rotating cam (Inner focus)||1,900 g||174 mm||113 mm||Built-in||100 mm Screw-in|
|180 mm F2.8||14°||5–5||Auto||2.8–32||2 m||32×21 cm||Straight helicoid||700 g||124 mm||80 mm||Built-in||72 mm Screw-in|
|200 mm F4||12°||5–4||Auto||4–32||2.5 m||36×24 cm||Straight helicoid||510 g||127 mm||67 mm||Built-in||55 mm Screw-in|
|200 mm F5||12°||6–5||Auto||5–32||2.5 m||36×25 cm||Straight helicoid||380 g||105 mm||62 mm||Built-in||49 mm Screw-in|
|250 mm F2||10°||12–9||Auto||2–22||2.2 m||25×17 cm||Rotating cam (Inner focus)||3,900 g||246 mm||142 mm||Built-in||Slip-in (46 mm rear filter)|
|300 mm F4.5||8°||6–4||Auto||4.5–32||3.5 m||33×22 cm||Straight helicoid||1,100 g (1,020 g without tripod collar)||181 mm||80 mm||Built-in||72 mm
|350 mm F2.8||7°||9–7||Auto||2.8–32||3 m||25×17 cm||Rotating cam (Inner focus)||3,900 g||280 mm||142 mm||Built-in||Slip-in (46 mm rear filter)|
|400 mm F6.3||6°||5–5||Auto||6.3–32||5 m||36×24 cm||Straight helicoid||1,300 g||255 mm||80 mm||Built-in||72 mm Screw-in|
|500 mm F8Reflex||5°||5–2||-||Single aperture of F8||4 m||28×19 cm||Straight helicoid||590 g||97 mm||81 mm||Built-in||72 mm Screw-in|
|600 mm F6.5||4°||6–4||Auto||6.5–32||11 m||55×37 cm||Rack and pinion||2,800 g||377 mm||110 mm||Built-in||100 mm Screw-in|
|1000 mm F11||2.5°||5–5||Auto||11–45||30 m||98×65 cm||Rack and pinion||4,000 g [4,150 g]||662 mm||110 mm||Built-in||100 mm Screw-in|
|28–48 mm F4||75°–49°||8–8||Auto||4–22||0.65 m||74×49 cm (28 mm) 46×31 cm (48 mm)||Rotating helicoid||300 g||54 mm (at 48 mm setting)||65 mm||55 mm Screw-in||49 mm Screw-in|
|35–70 mm F3.5–4.5||63°–34°||9–8||Auto||3.5–22||0.45 m||21.7×14.5 cm (close focus, 70 mm)||Rotating helicoid||190 g||51 mm||62 mm||51 mm Slip-on||49 mm Screw-in|
|35–70 mm F3.5–4.8||63°–34°||7–7||Auto||3.5–22 (35 mm) 4.8–32 (70 mm)||0.4 m||22×15 cm||Straight helicoid||185 g||65 mm||63 mm||52 mm Screw-in||52 mm Screw-in|
|35–70 mm F3.6||63°–34°||10–8||Auto||3.6–22||0.8 m||72×48 cm (35 mm) 37.5×25 cm (70 mm)||Straight helicoid||400 g||74 mm||67 mm||60 mm Slide-on||55 mm Screw-in|
|35–70 mm F4||64°–34°||7–7||Auto||4–22||0.75 m||72×48 cm (35 mm) 36×24 cm (70 mm)||Straight helicoid||385 g||71 mm||69 mm||57 mm Slide-on||55 mm Screw-in|
|35–70 mm F4 Auto Focus||63°–34°||9–8||Auto||4–22||0.75 m||72×48 cm (35 mm) 36×24 cm (70 mm)||Rotating helicoid||550 g (without batteries)||70 mm||92 mm||55 mm Screw-in||55 mm Screw-in|
|35–80 mm F2.8||63°–30°||16–14||Auto||2.8–22||0.6 m||62×41 cm (35 mm) 31×20 cm (80 mm)||rotating focusing helicoid, rotating cam zoomring||650 g||99 mm||69 mm||Bayonet mount||62 mm Screw-in|
|35–105 mm F3.5–4.5||63°–23°||16–12||Auto||3.5–22 (35 mm) 4.5–22 (105 mm)||1.5 m (0.31 m at close focus)||129×86 cm (35 mm) 45×30 cm (105 mm) close focus: 18×12 cm (35 mm) 25×17 cm (105 mm)||rotating focusing helicoid and push-pull zoomring||470 g||85 mm||64 mm||55 mm Screw-in||55 mm Screw-in|
|50–250 mm F5||47°–10°||13–10||Auto||5–32||1.80 m (1.53 m at 250 mm, close focus)||103×69 cm (50 mm) 22×14 cm (250 mm)||rotating focusing helicoid and push-pull zoomring||780 g||140 mm||72 mm||Built-in||55 mm Screw-in|
|65–200 mm F4||37°–12°||14–11||Auto||4–32||1.2 m (0.85 m at close focus, 200 mm)||48×32 cm (65 mm) 17×11 cm (200 mm) 12×8 cm (200 mm, close focus)||rotating focusing helicoid and push-pull zoomring||730 g||147 mm||71 mm||Built-in||55 mm Screw-in|
|70–210 mm F4.5–5.6||34°–11°||10–7||Auto||4.5–22 (70 mm) 5.6–28 (210 mm)||1.14 m||?||Straight helicoid||335 g||103 mm||63 mm||52 mm Screw-in||52 mm Screw-in|
|75–150 mm F4||32°–16°||15–11||Auto||4–22||1.6 m||64×42 cm (75 mm) 32×21 cm (150 mm)||Revolving helicoid||440 g||115 mm||63 mm||Built-in||49 mm Screw-in|
|85–250 mm F5||29°–10°||15–11||Auto||5–32||2 m||66–44 cm (85 mm) 23×15 cm (250 mm)||Revolving helicoid||890 g||196 mm||70 mm||Built-in||55 mm Screw-in|
|100–200 mm F5||24°–12°||9–6||Auto||5–32||2.4 m||69×46 cm (100 mm) 37×25 cm (200 mm)||rotating focusing helicoid and push-pull zoomring||570 g||148 mm||63 mm||Built-in||49 mm Screw-in|
|20 mm F2||9° at highest magnifi-cation||6–4||Auto||2–16||-||0.86×0.57 cm (4.2×) 0.26×0.18 cm (13.6×)||with Auto Bellows, 65–116, Auto Extension Tube 14, 15; fine focusing straight helicoid built-in||170 g||46 mm||60 mm||not necessary||-|
|20 mm F3.5||9° at highest magnifi-cation||4–3||Manual||3.5–16||-||0.84×0.56 cm (4.3×) 0.29×0.19 cm (12.4×)||with Auto Bellows||70 g||20 mm||32 mm||Not necessary||21 mm Slide-on|
|38 mm F2.8||9° athighest magnifi-cation||6–4||Auto||2.8–22||-||0.21×0.14 cm (1.7×) 0.54×0.36 cm (6.7×)||with Auto Bellows, 65–116, Auto Extension Tube 14, 15; fine focusing straight helicoid built-in.||170 g||46 mm||60 mm||Not necessary||-|
|38 mm F3.5||9° at highest magnification||5–4||Manual||3.5–16||-||0.20×0.13 cm (1.8×) 0.59×0.39 cm (6.1×)||with Auto Bellows||90 g||28 mm||43 mm||Not necessary||32 mm Slide-on|
|80 mm F4 (Manual)||9° at highest magnifi-cation||6–4||Manual||4–22||-||7.20×4.80 cm (2.3×) 1.80×1.20 cm (2.0×)||with Auto Bellows||200 g||46 mm||59 mm||Not necessary||49 mm Screw-in|
|80 mm F4 (Auto)||9° athighest magnifi-cation||6–4||Auto||4–32||0.23 m||7.20×4.80 cm (2.3×) 1.80×1.20 cm (2.0×)||with Auto Bellows, 65–116; fine focusing straight helicoid built-in||170 g||33 mm||60 mm||not necessary||49 mm Screw-in|
|135 mm F4.5||18°||5–4||Auto||4.5–45||0.6 m||7.2×4.8 cm||with Auto Bellows, 65–116; fine focusing straight helicoid built-in||320 g||47 mm||60 mm||57 mm Slide-on||55 mm Screw-in|
|24 mm F2.8AF||84°||8–7||Automatic control on camerabody||2.8–22||0.25 m||24×16 cm||Driven by AF/PF coupler on camera body||170 g||32 mm||62 mm||Built-in||49 mm Screw-in|
|28 mm F2.8AF||75°||6–6||Automatic control on camera body||2.8–22||0.3 m||27×18 cm||Driven by AF/PF coupler on camera body||170 g||32 mm||62 mm||Built-in||49 mm Screw-in|
|50 mm F1.8AF||47°||6–5||Automatic control on camera body||1.8–22||0.45 m||24×16 cm||Driven by AF/PF coupler on camera body||170 g||32 mm||62 mm||Built-in||49 mm Screw-in|
|50 mm F2PF||47°||6–4||Automatic control on camera body||2–22||0.45 m||24×16 cm||Driven by PF coupler on camera body||150 g||37 mm||64 mm||Slide-on||49 mm
|50 mm F2.8AF Macro||47°||8–7||Automatic controlon camera body||2.8–32||0.2 m||3.6×2.4 cm||Driven by AF/PF coupler on camera body||340 g||57 mm||66 mm||Built-in||49 mm Screw-in|
|28–85 mm F3.5–4.5AF||75°–29°||14–11||Automatic control on camera body||3.5–22 (28 mm) 4.5–27 (85 mm)||0.8 m (at close focus: 0.6 m)||85×57 cm (28 mm) 22×15 cm (85 mm)||Driven by AF/PF coupler on camera body||480 g||84 mm||69 mm||Slide-on||55 mm Screw-in|
|35–70 mm F3.5–4.5AF||63°–34°||9–8||Automatic control on camera body||3.5–22 (35 mm) 4.5–32 (70 mm)||0.75 m (at close focus: 0.45 m)||40.4×27 cm (35 mm) 21.7×14.5 cm (70 mm, close focus)||Driven by AF/PF coupler on camera body||250 g||53 mm||69 mm||Slide-on||49 mm Screw-in|
|35–70 mm F3.5–4.5PF||63°–34°||9–8||Automatic control on camera body||3.5–22 (35 mm) 4.5–32 (70 mm)||0.75 m (at close focus 0.45 m)||40.4×27 cm (35 mm) 21.7×14.5 cm (70 mm, close focus)||Driven by PF coupler on camera body||250 g||53 mm||69 mm||Slide-on||49 mm Screw-in|
|35–105 mm F3.5–4.5AF||63°–23°||14–13||Automatic control on camera body||3.5–22 (35 mm) 4.5–27 (105 mm)||1.5 m (at close focus: 0.85 m)||129×86 cm (35 mm) 22×14 cm (105 mm, close focus)||Driven by AF/PF coupler on camera body||460 g||84 mm||69 mm||Slide-on||55 mm Screw-in|
|70–210 mm F3.5–4.5AF||34°–11°||12–9||Automatic control on camera body||3.5–22 (70 mm) 4.5–32 (210 mm)||1.5 m (at close focus: 1.35 m)||52×34 cm (70 mm) 18×12 cm (210 mm, close focus)||Driven by AF/PF coupler on camera body||790 g||125 mm||76 mm||Slide-on||55 mm Screw-in|
 Prototype lenses
Here is a list of the manual Zuiko lenses that were never marketed:
- 18 mm/f3.5, prototype of 18 mm/f3.5, L.zuiko with 12 elements 10 group, fixed 72 mm thread
- 50 mm/f2 pancake, prototype of 40 mm/f2 pancake
- 85 mm/f1.4, prototype, with GRIN (GRadient INdex of Refraction) elements
- 160 mm/f3.5, prototype
- 300 mm/f6.3, prototype
- 400 mm/f4.5, prototype
- 500 mm/f5.6, prototype
- 800 mm/f9, prototype
- 1200 mm/f14, prototype
- 24–40 mm/f4, prototype, More Info
- 90–250 mm/? prototype of 85–250/5 – Unknown max aperture, maybe F4 or F3.6
- motor drives and exchangeable camera back for 250 exposures
- lighting: dedicated flashes, shoes, cords, connectors, power sources, adapters and filters
- interchangeable focusing screens instead of bulkier exchangeable finders
- macrophotography: extension tubes, stands & bases, lightings and accessories
- microphotography: systems and connecting, focusing, automatic and manual exposure units
- technical photograph: data recording backs, endoscope and astrophotography adapters
- cases, grips, cable release, battery holders
 See also
- Four Thirds System
- Olympus OM-D E-M5, the first of a new line of mirrorless interchangeable-lens cameras inspired by the OM external design
- Dandelion chip
- ""OM system" 35 mm single lens reflex cameras sales terminated" (Press release). Olympus Optical Co., Ltd. January 17, 2002. Retrieved 2006-08-17.
- Hawkins, R. Lee (2003-08-11). "What years were the various OM cameras produced?". Olympus OM SLR FAQ. Retrieved 2006-08-17.
- Kouichi Akagi. "interview with Yoshihisa Maitani". Asahi Camera magazine (March 2002). Archived from the original on 2009-10-21. Retrieved 2006-08-16.
- Unofficial Olympus OM Sales Information File, Hans van Veluwen
- Olympus OM-1(n) & OM-2 (n) SLR cameras, Rick Oleson, Bruce hamm, Simon Evans & Mark Dapoz; Photography in Malaysia
|Wikimedia Commons has media related to: Olympus OM System|
- Olympus History: OM Series Olympus Corporation history page.