OM System OM-1 vs Sony A7S

Olympus OM System OM-1 vs Sony Alpha A7S: A Deep Dive into Pro Mirrorless Titans from Different Eras

In the rapidly evolving world of mirrorless cameras, making the right choice can sometimes feel like navigating a labyrinth without a map. Today, I’m putting two intriguing contenders head-to-head: the 2022 Olympus OM System OM-1 and the venerable 2014 Sony Alpha A7S. These cameras, separated by eight years - and quite different design philosophies - address overlapping, yet distinct professional and enthusiast needs.

Throughout this comprehensive 2500-word exploration, I’ll draw on extensive real-world testing, sensor analysis, autofocus evaluation, and user experience insights. Whether you shoot portraits, wildlife, landscapes, or video, this detailed comparison aims to clarify what each camera brings to the table - and who should care.

Getting a Feel: Size, Ergonomics, and Handling in Daily Use

First impressions count, and for cameras, physical design defines that impression. The Olympus OM System OM-1 embraces a classic SLR-style mirrorless form factor, whereas Sony’s Alpha A7S also adopts an SLR style but with the slimming associated with early full-frame mirrorless.

Olympus roughly measures 135x92x73mm and weighs in at 599g, while the A7S is smaller at 127x94x48mm and lighter at 489g. What this means practically is that Olympus feels chunkier and more robust in-hand, better suited for longer shooting sessions where tactile control and grip stability count. Sony’s smaller footprint favors portability, especially for travel or street photographers who prize discretion.

The OM-1’s traditional, slightly deeper grip combined with weather sealing (environmental sealing, in fact) instills confidence shooting outdoors in challenging conditions. I spent several wet and windy afternoons with the OM-1, and it withstood exposure without a hitch; meanwhile, the A7S is weather resistant but noticeably less stout - realistic caution is advised with moisture.

Looking down from the top view, Olympus gives you more dedicated dials and physical controls - the kind I appreciate when switching settings quickly. Sony’s control surface is cleaner but a bit minimalist by comparison, relying more on menus and rear control wheels. Neither camera features illuminated buttons, which can be a minor inconvenience in dim lighting.

For users who want a no-nonsense, rugged feel with quick access to core settings, the OM System OM-1 nudges ahead ergonomically. But if you want lean packing with an emphasis on travel weight, the Sony A7S remains a strong candidate.

The Sensor Wars: Resolution, Size, and Image Quality Breakdown

At the heart of any camera lies the sensor - the delicate crucible where photons become images. Here we bump into Olympus’ Four Thirds-sized sensor versus Sony’s larger full frame.

The OM System OM-1 sports a 20MP stacked BSI Live MOS sensor sized 17.4x13mm (226.2mm²), specialized for speed, dynamic range, and in-body image stabilization synergy (five-axis sensor-based). In contrast, the Sony A7S wields a 12MP full-frame CMOS sensor measuring 35.8x23.9mm (855.62mm²). The Sony sensor’s area is almost four times larger, a massive physical advantage for gathering light.

But don't let the megapixel difference mislead you about image detail. The OM-1’s higher 20MP count provides greater resolution, vital for cropping or large prints. The Sony’s 12MP maximum resolution (4240x2832 pixels) means fewer pixels but enormous pixel sites that excel in noise control and extreme low-light conditions.

My extensive side-by-side testing shows:

• Dynamic Range: Sony’s A7S shines in shadow recovery and highlight retention with a DXO dynamic range score around 13.2 EV. The OM-1, with its modern sensor technology and stacking, delivers impressive dynamic range for Four Thirds but cannot match full frame breadth.

• Color Depth: The A7S couples impressive 23.9 bits color depth with a natural colorimetric response. The OM-1 is excellent for a Micro Four Thirds sensor but ranks understandably behind.

• High ISO/Low Light: Here the Sony Alpha A7S leads decisively. Its maximum ISO rating officially reaches a staggering 409,600 ISO (boosted), with usable results deep into very dim scenes, ideal for night and astro photography. The OM System OM-1’s maximum boosted ISO of 102,400 also impresses, especially with in-body stabilization to support longer exposures. Yet, noise levels become more visible earlier.

Interface and Viewfinding Experience: Stay Connected to Your Shot

Photographers live through their viewfinders and LCD displays. Let’s see how these tools compare for framing and previewing your shots.

Both cameras sport a 3-inch display panel, but the OM-1’s touchscreen brings a high resolution of 1620k dots with a fully articulating design. This flexibility is invaluable for macro shooters, videographers, and unconventional angles, making composing shots from waist height or awkward angles easier. Sony’s A7S offers a tilting 1230k-dot LCD, without touchscreen support - functional but less versatile for street, video, or vlogging.

In terms of the electronic viewfinder, the OM-1 boasts an impressive 5760k-dot OLED with 100% coverage and 0.83x magnification - sharp and immersive. The Sony A7S’s EVF resolution is lower at 2359k dots, with 0.71x magnification but also featuring full coverage. While the Sony is very usable, the OM-1’s viewfinder feels more modern and crisp in demanding situations.

One feature I particularly value on the OM System is the presence of a live, responsive touchscreen autofocus point selection, gadget control, and menus - all helping to streamline workflows on the fly.

Autofocus Smackdown: Speed, Precision, and Tracking in the Field

Autofocus remains among the most crucial performance aspects that separate cameras for many genres such as wildlife and sports.

The OM System OM-1 employs a hybrid AF with 1053 focus points relying heavily on both phase and contrast detection, including face and animal eye detection. Sony’s Alpha A7S uses a simpler 25-point contrast detection system with no phase detection on the sensor itself.

This technology gap represents a huge advantage for Olympus in autofocus speed and reliability. During fast-action outdoor shooting - such as birds in flight or sporting events - the OM-1 locked subjects quicker, maintained tracking with fewer lost acquisitions, and performed well under low light. Its animal eye detection is especially useful for wildlife photographers tracking unpredictable animals.

The Sony A7S, meanwhile, lagged in continuous autofocus performance due to relying primarily on contrast detection, leading to a hunting delay comparatively. For portraiture, both cameras offer face detection AF, but the OM-1 has the edge with faster acquisition and improved eye AF precision.

Speed burst rates reinforce this difference: OM System OM-1 performs at a crisp 10fps continuous shooting, whereas Sony caps at 5fps - less competitive for action or wildlife photographers who rely on high frame rates.

Handling Specialty Genres: Who Wins in Portrait, Landscape, Wildlife, and More?

A nuanced capacity to excel at specific photography types is what differentiates specialized cameras from generalists.

• Portraits: The OM-1’s higher megapixel count and powerful autofocus, supplemented by excellent 5-axis IBIS, create images with beautiful skin tone rendition and creamy bokeh. The Micro Four Thirds lens ecosystem - extensive with 118 lenses - includes many fast primes optimized for flattering shallow depth of field. Sony’s A7S excels in low light portraits but its 12MP resolution constraints diminish cropping flexibility.

• Landscape Photography: The Sony A7S’s full-frame sensor delivers superior dynamic range, which helps in high-contrast scenes. Additionally, native weather sealing aids diversification in tough environments. Olympus also offers strong weather resistance and can engage ISO settings to hold shadow detail. Landscapers who need resolution for giant prints might prefer OM-1’s 20MP sensor.

• Wildlife Photography: While Sony’s visited legacy in wildlife through higher-sensor full frame, the OM-1’s autofocus system and faster 10fps shooting give it an advantage in predictably capturing creatures in motion. The 2.1x focal length multiplier on the OM-1 is beneficial with available super telephoto Micro Four Thirds lenses, offering reach advantage.

• Sports Photography: Similar analysis applies here, with the OM-1’s tracking and burst rate making it better suited for fast sports action.

• Street Photography: Sony’s smaller body and lighter build favor discreet shooting. However, the OM-1’s articulating screen and packable weather sealing means it covers more adverse conditions.

• Macro Photography: OM-1 supports focus bracketing and stacking features highly desirable for macro use, which the Sony lacks. Combined with the rich Micro Four Thirds macro lens lineup, that makes Olympus a compelling macro choice.

• Night/Astro Photography: Here Sony’s ability to push extremely high ISOs with clean noise performance and longer native exposures is unsurpassed even today. The OM-1 is capable, but the Sony wins convincingly on ultra-low-light quality.

• Video Capabilities: The OM System OM-1 supports 4K video up to 60p in H.264/H.265 codecs with USB 3.1, mic/headphone jacks, and extensive in-body stabilization - ideal for handheld shooters. The Sony A7S was a trailblazer in video but supports 4K max at 30p (XAVC S, AVCHD), HDMI clean outputs, and some slow-motion at 120fps in 720p. While video-centric users may appreciate the legacy of the A7S, the OM-1 offers a more contemporary video package.

• Travel Photography: The Sony’s smaller size and lighter weight give it the edge for compact packing. However, the OM-1’s more versatile screen, weather sealing, and battery life (520 vs. 360 shots) make it equally compelling when you want reliability.

• Professional Workflows: Both cameras support RAW shooting, but the OM-1’s dual UHS-II SD card slots afford faster buffer clearing and backup options, important for intensive professional shooting. Sony’s single slot can be a limitation here.

The Lenses and Ecosystem: Compatibility and Creative Options

Lenses define photographic versatility.

• The OM System OM-1 benefits from the mature and extensive Micro Four Thirds lens ecosystem, with approximately 118 compatible lenses ranging from ultra-wide to super-telephoto and specialized optics for macro and portraiture. This system has the advantage of generally smaller, lighter lenses complementing the compact camera body.

• Sony’s A7S uses the full-frame Sony E mount, boasting around 121 lenses - some native, some third-party with high-performance glass appealing to professionals. These lenses tend to be larger and heavier but provide incredible image quality and reach.

If you already own lenses in either system or have specific needs for super-telephoto reach or ultra-fast primes, this ecosystem factor significantly influences camera choice.

Build Quality, Durability, and Environmental Sealing

Both cameras feature weather-resistant builds, though Olympus has pushed for more ruggedness and freezeproof tolerance. In real-world use, the OM-1 feels like a tool designed for tough fieldwork. Sony’s A7S, while solid, demands more care in adverse weather.

Battery Life and Storage: Managing Long Shoots

Battery life is a key concern for professionals and travelers alike.

• The OM System OM-1 provides approximately 520 shots per charge with the BLX-1 battery - a generous figure supported by energy-efficient processor architecture (undisclosed proprietary chip).

• Sony’s older NP-FW50 battery gives about 360 shots realistically, with fewer power management refinements.

Storage-wise, Olympus provides dual SD card slots compatible with UHS-II speeds on the primary slot, aiding fast buffering and backup redundancy. Sony’s single SD and Memory Stick slot reduces flexibility, potentially leaving users more vulnerable to card failure or buffer limits during extended bursts.

Connectivity, Workflow Integration, and Future-Proofing

Both cameras have built-in Wi-Fi for wireless image transfer and remote control. The Olympus includes Bluetooth but lacks NFC, while the Sony A7S features NFC but no Bluetooth - a sign of their respective development eras.

USB connectivity on the OM-1 is USB 3.1 Gen 1 (5 Gbps), enabling faster tethering and file transfer compared to Sony’s USB 2.0 offering.

For video, both cameras have microphone and headphone ports, giving users professional audio recording options.

Price-to-Performance: Getting the Most Bang for Your Buck

As of now, the Olympus OM System OM-1 retails around $2199, while the Sony Alpha A7S is approximately $1998 - although the A7S is no longer a current production model, prices vary widely in used and refurbished markets.

Considering technology advances, especially sensor performance, autofocus, video, and ergonomics, Olympus commands a premium justified by its fresh design and capabilities.

For budget-conscious shooters who prioritize ultra-low-light video or astrophotography, a used Sony A7S might still provide excellent value.

Sample Images: Seeing Is Believing

No review would be complete without visual evidence.

OM System OM 1 front OM System OM 1 screen back Sony A7S front Sony A7S screen back

These side-by-side comparisons clarify differences: the OM-1’s output reveals sharp, detailed landscapes and vibrant, natural portraits due to its higher resolution sensor. The Sony’s images shine in low light and highlight nuanced shadow details but at lower overall resolution.

Performance Scores by Discipline: Who Excels Where?

Let’s summarize with a scorecard, synthesizing objective and subjective factors:

Final Thoughts: Which One Is Right for You?

The Olympus OM System OM-1 emerges as a highly versatile, modern powerhouse that can handle most photography disciplines with aplomb, especially excelling in autofocus precision, shooting speed, and rugged build. It’s the sensible choice for professionals seeking a rich feature set, excellent weather sealing, and an extensive lens lineup in a compact but sturdy body.

On the other hand, the Sony Alpha A7S remains a legend in low-light and video circles - with superb noise performance, a big full-frame sensor, and a lighter footprint. For astro and night shooters, and for those who want the full-frame “look” at an affordable price, the A7S is still relevant, especially on the used market.

Who Should Buy the Olympus OM System OM-1?

• Wildlife and sports photographers needing high-speed AF and fast continuous shooting
• Macro shooters who will benefit from focus stacking and bracketing
• Videographers wanting 4K 60p with great in-body stabilization
• Outdoor enthusiasts requiring robust weather sealing and battery life
• Micro Four Thirds system users invested in compact lenses

Who Should Consider the Sony Alpha A7S?

• Photographers specializing in night, astro, or low-light portraiture
• Those with a preference for full-frame rendering and shallow depth of field
• Shutterbugs prioritizing lightweight carry for street and travel photography
• Videographers who appreciate the camera’s proven 4K capabilities and older but solid codec options
• Buyers on a budget, willing to take advantage of second-hand discounts

In today’s milieu, there’s no universal “best” - only the smart choice aligned with your craft and creative goals. Both of these cameras bring unique strengths from different epochs of mirrorless innovation. I hope this detailed comparison offers you clarity backed by hands-on experience and technical scrutiny to chart your photographic journey forward.

Happy shooting!