Olympus OM-1/2/3/4
The Olympus OM bodies were divided in a high range and a middle range. The one digit models were the high range.
Contents
The OM-1 and OM-2
The very first model was presented at the Photokina ok Köln in 1972 and was called the Olympus M-1. Very soon a complaint from Leica forced Olympus to rename the M-1 to OM-1, and apart from the name the two models are identical. However bodies and lenses with the M name are very rare and sought after by collectors.
The OM-1 is an all mechanical single lens reflex. It has a very large viewfinder with interchangeable screens but a fixed prism. It also has a through the lens exposure meter commanding a needle visible in the viewfinder. It has a very compact body, which will be essentially retained on later models.
Originally, you had to modify the bottom plate to mount a motor winder on the OM-1. In 1974 was launched the OM-1MD, MD for Motor Drive, on which a motor drive can be attached with no modification. This new version wears a small plate marked MD on the front.
In 1975 in a salon in Paris was presented the OM-2, which is the automatic version of the OM-1. The body is externally the same, but the shutter is an electronic one and the exposition is automatic with aperture priority, or manual. The exposure meter is able to measure the quantity of light reflected by the film and compensate any variation of light during the exposure. It was the first time this feature was introduced.
The OM-2 introduced for the first time the automation of the flash with a through the lens measure. This feature simplifies greatly the flash exposure, and is today used in all the cameras. The dedicated flash is the Olympus Quick Auto 310, and the system is unfortunately not compatible with the later T series flash units introduced with the OM-1n and OM-2n.
In 1979 were introduced the OM-1n and OM-2n.
The OM-1n is the same as the OM-1 with the following modifications:
- a redesigned film advance lever
- a flash ready/sufficient flash LED in the viewfinder, as well as automatic X-sync regardless of the position of the speed ring and the FP/X switch, when it is used with a T-series flash unit mounted on Flash Shoe 4.
The OM-2n, based on the OM-2, has the same modifications plus:
- a direct contact inside for Recordata Backs
- an exposure compensation warning flag
- full-frame averaging at all shutter speeds
- 120 second exposure limit on auto (OM-2 limit was 60 seconds).
The OM-3 and OM-4
The OM-2 SP / OM-2 S
Although its name suggests that this model is a continuation of the OM-2 line, the OM-2S has more in common with the OM-4 than the OM-2. Compared to the OM-2n, the OM-2S adds:
- programmed exposure automation (camera chooses both aperture and shutter speed)
- a spot meter for use in manual moded
- the hot shoe is not removeable
- the ISO range is extended from 1600 to 3200
- the viewfinder indicators are LCDs
- the self timer has mirror prefire.
