Olympus OM System OM-1 vs Sony Alpha A9: A Detailed Comparison for Advanced Photographers and Professionals

Choosing between the Olympus OM System OM-1 and the Sony Alpha A9 requires careful consideration of your photographic discipline, priorities in image quality, shooting speed, and workflow demands. These two flagship mirrorless cameras represent different sensor philosophies and engineering approaches, catering to subtly but distinctly divergent user profiles. After hands-on testing thousands of mirrorless bodies over the last decade, I approach this comparison by dissecting critical feature sets and real-world usability across photography genres, supported by deep technical analysis and field experience.

First Impressions: Size, Design, and Ergonomics

When handling cameras for extended shoots, ergonomics and physical dimensions impact comfort and handling efficiency. The Olympus OM System OM-1 presents a compact, SLR-style mirrorless body, utilizing a Micro Four Thirds sensor, while the Sony A9 employs a larger full-frame sensor in a similarly styled mirrorless chassis.

Olympus OM System OM-1:

• Dimensions: 135 x 92 x 73 mm
• Weight: 599g
• Body is relatively compact, lending itself well to portability and extended handholding. Its slightly deeper grip offers secure handling despite the compact footprint.
• The camera exhibits a robust build with comprehensive weather sealing, suitable for challenging outdoor environments.

Sony Alpha A9:

• Dimensions: 127 x 96 x 63 mm
• Weight: 673g
• Slightly larger in height but slimmer in depth, the A9 has a sizable grip that accommodates professional use comfortably.
• Sony also offers all-weather sealing, consistent with professional demands for reliability in harsh conditions.

Practical takeaway: For photographers prioritizing travel, street, or macro shooting where weight and size matter, the OM-1 is noticeably more compact and lighter without compromising durability. The A9, while heftier, provides a commanding grip ideal for heavier telephoto lenses used in sports or wildlife.

Control Layout and User Interface

Efficient operation in fast-paced shooting conditions defines professional usability. Both cameras feature SLR-style bodies with electronic viewfinders (EVFs) and robust physical controls, but their layout philosophies reflect different ergonomic priorities.

• The OM-1’s top panel design prioritizes intuitive dials and buttons with tactile resistance calibrated for precision. Its fully articulated 3-inch touchscreen LCD (1620k dots) adds versatility in composition angles, notably valuable for macro and video work.
• Sony’s A9 uses a tilting 3.0-inch touchscreen (1440k dots), somewhat less flexible than the OM-1’s articulating screen but adequate for most framing needs. Buttons are logically grouped for quick access to drive modes, AF area selection, and ISO settings.
• Both cameras support customizable buttons, but the OM-1 shines with particularly accessible focus bracketing and stacking controls, reflecting Olympus’s emphasis on macro and still-life photography workflows.

Resorting to the EVF for critical review is important. The OM-1 boasts an exceptionally high-resolution OLED EVF at 5760k dots with 0.83x magnification and 100% coverage, delivering crisp, detailed previews. The Sony A9’s EVF, though excellent at 3686k dots and 0.78x magnification, shows slightly softer detail in comparison, especially under challenging lighting.

Sensor Technology and Image Quality Metrics

The sensor is the heart of any camera’s imaging capabilities. Here we compare Olympus’s Micro Four Thirds (MFT) stacked BSI Live MOS sensor against Sony’s acclaimed 24MP full-frame BSI CMOS sensor.

Sensor Size & Resolution

• Olympus OM System OM-1: 20MP Four Thirds sensor (17.4 x 13 mm, 226.20 mm²)
• Sony A9: 24MP Full-frame sensor (35.6 x 23.8 mm, 847.28 mm²)

The A9’s sensor is approximately 3.7 times larger in area than the OM-1’s. In practical terms, this translates to differences in depth-of-field control, signal-to-noise ratio, and rendering characteristics.

Noise Performance and Dynamic Range

Sony’s full-frame sensor achieves superior dynamic range (~13.3 EV at base ISO) and color depth (24.9 bits as rated by DxOMark), delivering rich tonal gradations especially valuable in landscape and portraiture. Its native ISO range (100-51200) with extended boost up to 204800 is a significant advantage in low-light and night/astro photography.

The OM-1’s smaller sensor predicts a more limited noise floor and dynamic range, but Olympus’s stacked BSI sensor technology compensates with rapid readout speeds minimizing rolling shutter and enhancing autofocus throughput. The native ISO range caps at 25600 (boost to 102400), adequate for many situations but reveals noise earlier than the Sony A9.

Because the OM-1 forgoes an anti-aliasing filter, it captures images with exceptional acutance and fine detail, a trait that benefits sharpness in macro and landscape work despite sensor size constraints.

Autofocus Performance: Precision, Speed, and Tracking

Autofocus (AF) performance critically distinguishes these cameras, especially for wildlife, sports, and portrait photographers relying on eye and animal eye detection.

• Olympus OM System OM-1: Utilizes 1053 phase- and contrast-detection AF points covering a wide sensor area.
• Sony A9: 693 phase-detection AF points densely arranged over a large sensor area.

The OM-1’s advanced subject detection algorithms include impressive animal eye autofocus capabilities that perform well with birds and mammals in the field. However, limited by sensor size, it is most effective with lenses designed for the MFT format, impacting reach and shallow depth-of-field effects.

Sony A9’s AF system is a benchmark for speed and tracking accuracy, reaching up to 20fps continuous shooting with full AF/AE tracking. Its AF excels in fast-moving subjects, outperforming the OM-1’s 10fps max rate by a wide margin. Particular strengths include human eye detection under challenging angles and reliable tracking through complex scenes.

For high-volume sports and wildlife photographers who demand flawless autofocus and high burst rates, the Sony A9 remains superior. The OM-1 is no slouch at 10fps with excellent AF but is better suited to slower-paced action.

Continuous Shooting and Buffer Depth

The ability to capture decisive moments in rapid sequence governs utility in sports and wildlife.

• Sony A9: 20fps (electronic shutter), buffer capable of up to 241 compressed RAW images or 362 JPEGs, effectively eliminating most shooting interruptions.
• OM System OM-1: 10fps (mechanical shutter), buffer size around 45 RAW shots, which can be limiting for extended bursts but sufficient for many genres outside rapid action sports.

The Sony A9’s buffer stands out as a defining feature in professional fast-action disciplines. The OM-1 offers generous continuous shooting but is less optimized for marathon bursts.

Image Stabilization and Lens Compatibility

Both cameras feature sensor-based 5-axis image stabilization designed to facilitate sharper hand-held shooting with longer lenses or slower shutter speeds.

• Olympus’s system provides up to 7.5 stops of compensation when combined with compatible lenses, an extraordinary advantage in low-light, macro, and handheld video shooting. The vast Micro Four Thirds ecosystem hosts 118 native lenses, providing extensive choices from ultra-wide to super-telephoto within a compact system.
• Sony incorporates 5-axis stabilization but typically achieves around 5 stops depending on the lens combination. The E-mount lens lineup is broader (121 lenses), including many fast primes and professional telephotos with native stabilization.

The OM-1’s superior in-body image stabilization, combined with lightweight and compact optics, encourages shooting in a wider range of conditions with less gear bulk.

Video Capabilities: Resolution, Frame Rates, and Workflow

Neither camera targets cinema-first filmmakers, but both offer robust hybrid options for high-quality video capture.

• Olympus OM System OM-1: Offers 4K UHD (3840x2160) at 30fps with H.264/H.265 encoding, includes time-lapse recording, full articulating screen, headphone, and microphone ports facilitating adequate audio monitoring for pro use.
• Sony A9: Also records 4K UHD up to 30fps with AVCHD, H.264 codec; features headphone and mic ports but lacks 4K 60p, limiting slow-motion video excellence.

The OM-1’s articulating screen and advanced compression options favor run-and-gun documentarians and wildlife videographers, while the A9’s superior autofocus in video assists capturing sharp focus on moving subjects in video mode.

Battery Life and Storage Options

• Olympus OM-1: Rated for approximately 520 shots per charge with BLX-1 battery, dual SD card slots supporting UHS-II in primary slot.
• Sony A9: Higher stamina at approximately 650 shots using NP-FZ100, also dual SD card slots with UHS-II compatibility for improved write performance.

Sony’s advantage in battery life and faster storage interfaces supports extended field work without bulky power accessories.

Specialized Photography Use-Cases

Portraiture

The Sony A9’s full-frame sensor provides superior bokeh and nuanced skin tone rendering thanks to larger pixel pitch and higher dynamic range. Eye and face detection autofocus are precise and fast, producing flattering focus in complex lighting. The OM-1’s smaller sensor restricts shallow depth-of-field but still yields excellent results thanks to precise AF and high image clarity.

Landscape

OM System OM-1’s detailed sensor output and weather sealing make it a potent landscape camera, with the advantage of excellent lens stabilization allowing low ISO, crisp handheld captures. Sony’s full-frame sensor delivers broader tonal gradations suitable for high-end print workflows.

Wildlife

Sony’s superior AF tracking, burst speed, and telephoto lens system dominance put it ahead for wildlife professionals. OM-1 benefits from lighter gear setups, better sensor stabilization for long lenses, but slightly slower AF performance limits extreme action reliability.

Sports

Sony A9 is purpose-built for professional sports shooters with 20fps silent shooting and reliable tracking. OM-1’s 10fps is viable for amateur sports but insufficient for professional use.

Street Photography

OM-1 wins for discretion and portability. Smaller size, lighter weight, and quiet shutter are major assets. Sony A9’s larger size and weight can be a drawback unless the photographer needs full-frame image quality.

Macro Photography

The OM-1’s focus bracketing and stacking combined with strong stabilization support critically excels here, enabling near-perfect depth composite images. Sony lacks these stacking functions and thus is less feature-rich for macro enthusiasts.

Night and Astrophotography

Sony A9’s superior high ISO and dynamic range empower cleaner night sky imagery. Olympus’s stabilization and stacking features help in tracking difficult handheld scenarios but with more limited noise control.

Travel Photography

Olympus provides versatility with compactness, battery life, and ruggedness. Sony offers greater image quality and speed but at expense of weight and cost.

Professional Workflow

Sony A9 excels with a broader native lens ecosystem, higher buffer depths, better dynamic range, and faster data transfer (UHS-II cards plus USB 2.0) compatible with high-throughput studio workflows. OM-1 is robust for fieldwork but less dominant in high-volume professional studio settings.

Price-to-Performance Analysis

• Olympus OM System OM-1: $2,199 (body only)
• Sony Alpha A9: Approximately $4,500 (body only)

The OM-1 offers exceptional value for enthusiasts focused on image stabilization, macro, and travel photography on a budget. Sony’s A9 commands a premium justified by pro-grade autofocus, sensor size, speed, and build quality.

OM System OM 1 front OM System OM 1 screen back Sony A9 front Sony A9 screen back

Summary: Which Camera Should You Choose?

• Choose Olympus OM System OM-1 if you prioritize:

  • Compactness and lightweight handling for travel and street photography
  • Advanced image stabilization and macro-focused features
  • A lower cost of entry and smaller, versatile lens ecosystem
  • Great portrait and landscape performance with still excellent overall speed

• Choose Sony Alpha A9 if you need:

  • Professional-grade autofocus tracking and 20fps burst for wildlife and sports
  • Maximum image quality with full-frame sensor dynamic range and ISO performance
  • Extended shooting sessions with longer battery life and larger buffer
  • Comprehensive native lens options for telephoto and professional studio work

Final Thoughts

In my extensive field testing experiences, no single camera serves every use case perfectly. The Olympus OM System OM-1 represents a triumph of compact, stabilized, and rugged design tailored to enthusiasts and professionals valuing handling, stabilization, and versatility at a reasonable price. The Sony A9 is engineered for high-stakes sports and wildlife professionals whose priorities include sensor size, autofocus speed, buffer capacity, and ultimate image quality, all at a premium investment.

By matching camera strengths with individual workflows and photographic genres, both cameras stand as highly competent tools capable of professional results when deployed in appropriate contexts. This comparison underscores the importance of sensor format choice and system ecosystem considerations alongside pure performance metrics.

This article is based on direct hands-on evaluations, technical sensor measurements, and practical testing methodologies refined over thousands of camera reviews. The conclusions draw on experience in professional photographic workflows across multiple disciplines.