OM-4

Body group OM-4

The OM-4 replaced the OM-2n in 1984, and it was a worthy successor. Besides a more modern design with LED's instead of a meter, a shortest shutter speed of 1/2000 sec, a mechanical shutter speed of 1/60 sec, a built-in hot shoe and TTL Connector and a viewfinder illuminator, the most striking new features, which are multi-spot metering, automatic hilight/shadow correction and a long auto exposure time of 4 minutes, are even exciting today.
It incorporates the same features as its mechanical sister camera, the OM-3, and adds Auto Exposure, multi spot reading in both Manual and Auto Mode, an Exposure Memory of one hour, and of course TTL "OTF" Flash Exposure to it. Another difference is the presence of the new electronic self-timer in the OM-4; the OM-3 doesn't have a self-timer at all. The self-timer switch in the OM-4, which also serves as a switch to turn off the beeper, is identical to the self-timer in the OM-SP. When the self-timer is activated the mirror is locked up and the aperture is closed, which can help in reducing vibrations. All OM bodies that were introduced in the first half of the eighties had additional support for Motor Drive 2: advance to first frame when the back is closed. The OM-3 and OM-4 (and of course also their successors, the OM-3Ti and OM-4Ti) are the only bodies that also support motorized film rewind with Motor Drive 2.
The OM-4 was only made in black.

om-4a.jpg (27254 bytes)

Main specifications

Type: TTL auto-exposure 35 mm. Single Lens Reflex Camera.	Manual film advance: Film advance lever with 130° angle for one long or several short strokes and pre-advance angle 30°.
Film format: 24mm x 36mm.	Motor drive advance: With Motor Drive 1 or 2 unit attached, single frame and continuous advance at speed of 5 frames per second (at exposures of 1/500 sec. and above, with fresh batteries and at normal temperature and humidity).
Lens mount: Olympus OM Mount.	Film rewind: Rewind crank (motorized rewind with Motor Drive 2 possible).
Shutter: Electronically controlled focal plane shutter; 1/2000 sec. max. shutter speed; 1/60 sec. mechanical shutter speed.	Viewfinder: Viewfinder with dioptric correction; dioptric correction range from +1 to -3 diopters; finder viewfield: 97% of actual picture field; magnification: 0.84x at infinity with -0.5 diop. (50mm lens).
Synchronization: X contact (synchronization at speeds of 1/60 sec. or slower); hot shoe with contact for T series flash; 5-pin connector for T series flash; PC synchro socket.	Focusing screens: Wide selection of interchangeable screens (1- and 2-series). Supplied with Focusing Screen 1-13 (microprism/split image-matte type).
Light measuring method: Center-weighted, average light measurement, switchable to spot measurement; spot measurement selective in three modes: multispot, highlight and shadow-based methods.	Viewfinder information: LCD multi-mode display (2 min. limiter). Shutter speed, spot value(s), highlight mode, shadow mode, exposure compensation indicator, memory indicator. Markers for 3 stops under/over exposure in Manual Mode. LED indicator for flash ready / flash ok. Built-in illuminator (10 sec. limiter).
Automatic exposure control by average light measurement: TTL Direct "off-the-film" Light Measuring with aperture-preferred electronic shutter; exposure control range: about 1 min. ~ 1/2000 sec. (approx. -5EV~19EV at ISO/ASA 100, 50mm F1.4, normal temperature and humidity); ±2EV exposure compensation.	Self-timer: 12 sec. delay electronic self-timer.
Automatic exposure control by spot measurement: TTL spot metering memory system (with AE lock); exposure control range: about 4 min.~1/2000 sec. (approx. -7EV~19EV at ISO/ASA 100, 50mm F1.4, normal temperature and humidity); ±2EV exposure compensation.	Battery check: 3-level display with LED and auto tone; automatic lock when batteries exhausted.
Automatic exposure memory control: Exposure value memory system (60 min. limiter).	Power source: Two 1.5V silver-oxide batteries SR44 (Eveready EPX-76) or alkaline manganese batteries LR44.
Manual exposure control: B., 1 sec.~1/2000 sec. (synchronisation at speeds of 1/60 sec. or slower).	Camera back: Removable hinge type with memo holder; interchangeable with Recordata backs and 250 Film Back.
Film speed: ISO/ASA 6-3200.	Dimensions: 136x84x50mm (body alone).
	Weight: 540 gram (body alone).

OM-4 Brochure (7.3Mb).

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