By the early 1980s, Olympus knew the world was changing.
Photographers were asking for more flexibility, clearer controls,
but without the bulk and cost of professional bodies.
Enter the Olympus OM-20 (sold as the OM-G in North America) in 1983:
a smart, improved evolution of the popular OM-10.
Sleeker, tougher, and giving photographers full manual control out of the box,
the OM-20 showed that Olympus still believed beginners deserved serious tools.
What’s New with the OM-20
At first glance, the OM-20 looks very similar to the OM-10.
But several important changes make it a much more capable camera:
- Built-In Manual Control:
Unlike the OM-10, the OM-20 doesn’t need a Manual Adapter.
Manual shutter speeds are available straight from the dial. - LED Overexposure Warning:
An extra indicator in the viewfinder flashes if you’re about to overexpose. - Shutter Release Sensitivity Adjustment:
A small dial allows you to adjust how much pressure is needed to trip the shutter, rare even today. - Stronger Top Plate:
Switched from lightweight alloy to tougher material for better durability. - Improved Circuitry:
Faster metering response and reduced battery drain compared to the OM-10. - Better Viewfinder:
Still large and bright (~93% coverage) with improved shutter speed indicators.
These changes made the OM-20 feel faster, smarter, and more serious,
while still retaining the lightweight agility of the OM family.
Key Features of the OM-20
- Aperture Priority and Full Manual Modes:
Choose aperture priority for speed or full manual control when you want precision. - Bright Viewfinder:
Big, uncluttered, with LED speed indicators and overexposure warning. - Quartz-Timed Shutter:
Electronic speeds from 2 seconds to 1/1000s,
plus 1/45s mechanical backup if batteries fail. - TTL Flash Metering:
Through-the-lens flash support with Olympus T-series flashes. - Motor Drive Compatibility:
Accepts Winder 2 and Motor Drive 1 for automatic film advance. - Battery Powered:
Requires two SR44 or equivalent batteries for full operation.
How the OM-20 Improved on the OM-10
| Feature | OM-10 | OM-20 |
|---|---|---|
| Manual Shutter Control | Needs separate adapter | Built-in |
| Viewfinder Alerts | Basic shutter speed LEDs | Shutter speed LEDs + overexposure warning |
| Shutter Release Adjustment | None | Sensitivity adjustment dial |
| Top Plate Material | Alloy | Toughened composite |
| Circuitry | 1979-era | Faster, lower-drain 1983 update |
The OM-20 solved most of the OM-10’s minor frustrations
while keeping the winning formula: lightweight, affordable, OM System quality.
How to Estimate the Age of Your OM-20
| Serial Number Range | Approximate Production Years |
|---|---|
| 100000 – 500000 | OM-20 |
Production wasn’t massive,
making the OM-20 less common today than the OM-10.
Serial Location:
- Engraved on the top plate near the rewind crank.
Olympus OM-20: Full Specifications
| Specification | Detail |
|---|---|
| Year Released | 1983 |
| Shutter Speeds | 2s-1/1000s (Quartz-timed), 1/45s mechanical backup |
| Flash Sync | 1/45s |
| Metering | Centre-weighted average |
| Exposure Modes | Aperture Priority, Manual |
| Viewfinder Coverage | ~93% |
| Motor Drive Compatibility | Winder 2, Motor Drive 1 |
| Batteries | Two 1.5V SR44 or one 3V CR1/3N |
| TTL Flash Support | Yes |
| Body Material | Strengthened composite with OM compact form factor |
Manual for Download
OM-20 Final Word
The Olympus OM-20 is one of the best-kept secrets of the OM system.
Simple enough for a beginner.
Serious enough for a professional in a pinch.
And still carrying the essential DNA that made Olympus cameras loved worldwide:
small, tough, intuitive, precise.
If the OM-10 introduced photographers to the OM world,
the OM-20 showed them how to truly take control.