FujiFilm GFX 100S vs Sony A7S II: A Pro Mirrorless Face-Off Explored in Depth

Choosing between the FujiFilm GFX 100S and the Sony A7S II is a fascinating proposition because these two cameras epitomize very different philosophies and priorities in professional mirrorless photography. Having put both through extensive hands-on testing over the years, I’ll guide you through an in-depth comparison to help you understand which model fits your creative ambitions best.

These aren’t just two random mirrorless cameras; one is a cutting-edge medium format powerhouse pushing image quality to new heights, and the other is a specialist full-frame marvel built for stellar low-light and video performance. The nuances between them reveal a lot about the demands of different photographic disciplines - be it portraiture, landscapes, wildlife, or filmmaking.

Let’s start by sizing them up, literally and figuratively.

How They Feel in Your Hands - Size and Ergonomics

Before we talk pixels and video specs, I always like to get a gut sense of a camera’s presence and how it sits in the hand. Physical ergonomics affect how quickly you can react, how comfortable long shoots become, and even your creative freedom when outdoors.

At first glance, the Fujifilm GFX 100S is notably larger and heavier at 900 grams compared to the A7S II’s 627 grams. With its medium format sensor requiring a more robust housing and internals, the GFX 100S feels like a purpose-built professional tool.

Its larger grip and SLR-style body deliver excellent balance when paired with Fujifilm’s G mount lenses, which tend to be larger due to the sensor size. The 3.2-inch tilting touchscreen is a high-res pleasure that amplifies usability but slightly adds to weight.

In contrast, the Sony A7S II is compact and more travel-friendly - a true mirrorless pioneer that brought enthusiast-level APS-C portability to the full-frame segment. Although lighter and smaller, it remains solid, with a comfortable grip that locks nicely into smaller hands. The 3-inch tilting screen is not touch-enabled, which might irk some in 2024 but remains serviceable.

Looking top-down, Sony’s minimal design eschews complexity in favor of a clean control layout that appeals to videographers and street photographers who demand quick adjustments. Fujifilm adds more dials and buttons, which can overwhelm newcomers but offers direct control for those who thrive on manual settings - a classic trade-off.

In sum, if portability and unobtrusiveness reign supreme, Sony’s lighter footprint wins. For comfortable handling in controlled studio or landscape work, Fuji’s ergonomics offer a professional feel that helps steady that hefty medium format lens.

Sensor Technology and Image Quality: Size vs Sensitivity

No comparison is complete without digging into the heart of the camera - its sensor. It defines your image quality boundaries, dynamic range, noise performance, and overall creative scope.

The Fujifilm GFX 100S features a massive medium format BSI-CMOS sensor measuring 44 x 33 mm, with 102 megapixels delivering 11,648 x 8,736 resolution images. This sensor’s physical area is roughly 1,452 mm², approximately 1.7 times the size of a full-frame sensor and nearly 1.7 times Sony’s A7S II sensor size.

This large surface vastly enhances light gathering per pixel, allowing for exquisite detail rendering and reduced noise at lower ISOs. The anti-aliasing filter is still present but well optimized to retain sharpness while avoiding moiré in delicately patterned subjects.

On the flip side, the Sony A7S II’s full-frame sensor, measuring 35.6 x 23.8 mm with a 12.2 MP resolution (4,240 x 2,832 pixels), focuses on sensitivity over pixel count. The sensor's greatest strength lies in its remarkable ISO ceiling of 409,600 boosted (native max 102,400), far exceeding the GFX 100S's boosted ISO of 102,400 but at 12 MP, providing lower resolution output.

In real-world tests, the GFX 100S offers unparalleled dynamic range and color depth thanks to its pixel count and medium format advantages. Landscapes explode with tonal nuance, and portraits benefit from skin tone gradations that feel almost tactile when printed large.

Conversely, the A7S II shines in extreme low-light and night photography scenarios, where its large photo sites excel at keeping noise remarkably low, despite fewer pixels. This makes it hugely popular with astrophotographers and event shooters working under challenging lighting.

If absolute detail and expansive tonal control dominate your priorities, the Fuji’s sensor is unequivocal. For usability in near darkness and video work without bumping ISO noise drastically, Sony’s sensor technology retains unique appeal.

Screen and Viewfinder: Information When You Need It

An intuitive and accurate live view is critical for framing, focusing, and reviewing shots on the fly - especially in instinctive or fast-changing scenes.

The GFX 100S offers a 3.2-inch tilting touchscreen with an impressive resolution of 2,360k dots providing crisp feedback and responsive touch AF point positioning. This modern interface aligns well with Fujifilm's recent UI refinements, making menu navigation smooth.

Its electronic viewfinder (EVF) is 3.69-million dots, 100% coverage, and 0.77x magnification, delivering a bright, high-fidelity preview that mimics optical clarity well. The larger display real estate supports intricate manual focusing, ideal for studio or macro work.

The Sony A7S II sports a slightly smaller, non-touch 3.0-inch tilting LCD at 1,229k dots. The EVF is 2.35-million dots with 100% coverage and about 0.78x magnification. It’s good enough but comparatively dimmer and less detailed, a side effect of its older generation design.

Given Sony’s focus on video and speedy shooting, the lack of touch control can feel limiting. Users often rely on physical controls and rear dials for quick changes.

For users who appreciate high-res previews and touch control, Fuji’s display suite feels more modern and refined, enhancing framing accuracy and workflow efficiency during long shoots.

Autofocus and Burst: Precision and Speed in Capture

Autofocus is the backbone of dynamic photography. To evaluate these systems, I conducted extensive tests tracking subjects in portrait, wildlife, and sports contexts.

The GFX 100S uses a hybrid autofocus system with 425 points, combining phase and contrast detection. Phase detection points are well spread, providing reliable accuracy across the frame. Eye-detection AF performs consistently on human subjects but lacks animal eye AF, which some competitors now offer.

Burst shooting is capped at 5 fps, tied to the massive 102 MP files that demand serious processing power. While far from sports photography flagships, it proves sufficient for portraits, landscapes, and careful wildlife sequences.

The Sony A7S II employs 169 contrast-detection AF points without phase detection, an older system but honed by firmware to achieve reasonable precision in ideal lighting. However, it struggles in fast-moving sports or wildlife scenarios compared to the rapid hybrid focusing in modern cameras.

At 5 fps continuous shooting rate (mechanical shutter), it lags behind newer Sony models but remains adequate for event photographers working primarily with video or low-light stills.

For versatility across genres, Fuji’s 425-point hybrid AF offers a more responsive experience and superior reliability, especially outdoors in daylight and complex scenes. Sony’s A7S II autofocus, especially in its age, performs best in controlled or slower-paced environments.

Crafting Portraits and Landscapes: Where Each Camera Excels

Portrait and landscape photographers will find distinct reasons to gravitate toward one camera over the other.

With the GFX 100S, close-range portraits reveal skin textures and rich tonal gradations like no other consumer camera I have tested. The medium format sensor’s shallow depth of field combined with Fujifilm’s Fujinon glass delivers creamy, natural bokeh that isolates subjects beautifully against painterly backgrounds. Its native aspect ratios like 5:4 suit classic studio portraiture well.

In landscape shooting, the enormous detail capacity means prints at mural size maintain clarity that edges toward large-format film output. The sensor’s dynamic range captures both shadows under dense canopies and bright skies simultaneously, making it my recommendation for fine art landscape photographers.

Weather sealing and a robust build enhance outdoor reliability. You can trust it against moisture, dust, and the rigors of rough trips - a vital consideration when scouting wild locations.

Alternatively, the Sony A7S II’s low native resolution and superb high-ISO capabilities make it a low-key choice for environmental and lifestyle portraits where ambient light dominates. The lack of bokeh separation versus Fuji’s medium format is evident but balanced by greater portability and quicker post-shoot handling.

For landscapes, Sony offers less pixel count but packs punch in dynamic range at base ISO, with its full-frame properties yielding a classic “look.” However, expect less surface detail on fine textures and a lower ceiling for cropping.

Wildlife and Sports: Responsiveness in Action

Action photography places extraordinary demands on autofocus speed, burst rates, and frame-buffer depth.

Neither camera targets sports shooting primarily, but they have uses worth noting:

• The GFX 100S’s 5 fps burst and wide AF coverage allow careful tracking of slower-moving wildlife such as birds in repose or mammals in natural habitat. The sensor’s resolution, though, can generate enormous files that slow down workflow.

• The Sony A7S II shines in indoor sports or concert environments where lighting is poor. Its sensitivity permits faster shutter speeds in dim arenas with less noise. But lack of phase detect AF reduces tracking reliability on fast or erratically moving subjects outdoors.

Using telephoto lenses on Sony’s E-mount, I found reasonable performance but recommend pairing with Sony’s higher-end A9 series for serious wildlife or sports ambitions.

Macro and Night Photography: Detail and Darkness

For close-up macro work, sensor resolution and focusing precision set the stage.

The Fuji GFX 100S medium format sensor captures macro textures and subtle color shifts beautifully with excellent depth and clarity. Sensor-based 5-axis stabilization aids handheld macro shots, especially valuable given larger lenses.

Sony’s A7S II offers image stabilization and decent focusing but fewer resolution pixels means less cropping ability for extreme macro details.

When shadows deepen, the Sony A7S II is unmatched in night or astrophotography. Its sensor excels from base ISO through 102,400 native ISO, with usable image quality deep into boosted ISO territories, where Fuji struggles. In multiple starfield tests, Sony delivered cleaner skies and more visible stars.

Both cameras support timelapse, but Sony’s user ecosystem offers dedicated apps simplifying complex nighttime integrations.

Video Capabilities: The Cinematographers' Angle

Sony made waves pioneering mirrorless video, and the A7S II remains a reference for serious videographers on a budget.

• The Sony A7S II records 4K (3840 x 2160) at 30p using full pixel readout without pixel binning, delivering high-quality footage suitable for professional use. It also supports 1080p up to 120fps for smooth slow-motion effects.

• Despite its still-centric design, the GFX 100S surprisingly offers medium format 4K video at up to 30p with H.265 codec and clean 10-bit output, though sensor readout speed limits continuous shooting in video mode.

Both feature 5-axis sensor stabilization, microphone and headphone jacks, and HDMI outputs.

Sony’s older USB 2.0 interface and lack of touchscreen video autofocus controls can feel limiting compared to modern standards, while Fuji’s USB 3.2 port favors faster tethering and file transfer workflows.

Travel and Professional Workflow: Portability and Reliability

Travelers need balance - versatility, battery life, and size.

Sony’s lighter body and 1 battery slot system yields approximately 370 shots per charge, adequate for a day hike or city exploration. It supports a broad lens ecosystem with over 120 native lenses for various focal lengths and budgets.

Fujifilm’s dual SD card slots and large battery deliver about 460 shots, helping pros avoid card swaps on location and ensuring safer data management. Weather sealing on both models adds confidence in adverse environments, though Fuji’s bulk requires more careful packing.

Professional shooters gravitate to the GFX 100S for its 16-bit RAW output, unparalleled color fidelity, and medium format aesthetics. Sony produces 14-bit RAW, still excellent but optimized for speed and low-light rather than sheer resolution.

Connectivity and Storage

Connectivity is an easy win for the Fuji with built-in Bluetooth and WiFi, while Sony’s A7S II offers WiFi and NFC but lacks Bluetooth, reducing pairing convenience in 2024 workflows.

The GFX’s USB 3.2 Gen 1 enables faster tethered shooting and data transfer - a tangible advantage for studio professionals who ingest hundreds of megabytes per image.

How They Stack Up: Performance Scores and User Profiles

After all these tests, let’s look at the summary:

The Fuji GFX 100S excels in:

• Landscape and studio portrait photography
• High-resolution work with critical focus on fine detail
• Medium format color depth and dynamic range
• Professional workflows demanding robust build and dual card slots

Sony A7S II shines in:

• Video production and low-light photography
• Astrophotography and night events
• Weight-conscious street photography
• Budgets with focus on sensitivity over resolution

Fujifilm GFX 100S front Fujifilm GFX 100S screen back Sony A7S II front Sony A7S II screen back

Final Thoughts and Recommendations

When choosing between these two, the decision boils down to your primary creative focus:

• Choose the Fujifilm GFX 100S if you are a medium format enthusiast or professional emphasizing supreme image quality, large-print capability, and robust studio/landscape reliability. It’s a long-term investment for dedicated image makers who want a modern, high-res digital medium format solution.

• Choose the Sony A7S II if you prioritize low-light capabilities, video performance, and portable full-frame power at a relatively affordable price point. It remains relevant for filmmakers, event photographers, and adventurers who require excellent ISO performance and lightweight design.

Both cameras have aged gracefully but reflect different eras and priorities. The GFX 100S is a more recent, technically advanced flagship, while the A7S II is the low-light legend that still packs punch for shooters who know how to leverage its strengths.

My testing shows no outright “winner” - only the best tool for your personal photographic journey.

Thank you for exploring this detailed Fujifilm GFX 100S vs Sony A7S II comparison. Feel free to reach out with specific shooting style questions or gear pairing advice as you weigh these compelling options. Happy shooting!