The Samsung NX20 vs. Sony A7 III: An Expert’s Deep Dive into Two Transformative Mirrorless Cameras

When approaching a camera comparison that bridges generations and sensor formats - here, the compact APS-C Samsung NX20 from 2012 and the powerhouse 2018 full-frame Sony A7 III - it’s about more than specs on paper. It’s a study in how mirrorless tech evolved dramatically over a half decade, shifting the landscape for enthusiasts and pros alike. Having tested thousands of cameras extensively in different genres, I’m excited to guide you through an honest, granular comparison revealing what really separates these two, from sensor tech to ergonomics, autofocus, and beyond.

Below, we explore their core features through rigorous real-world use and technical analysis, mindful of their strengths and limitations as they stand in today’s photography ecosystem.

First Impressions: Size, Handling, and Build Quality

Before firing a single shot, your interaction with a camera’s physicality frames the entire experience. The Samsung NX20 is a compact, lightweight APS-C mirrorless that launched when the mirrorless field was nascent. It’s a neat, SLR-style body measuring 122x90x40mm and tipping the scales at just 341g with battery, making it very travel-friendly.

By contrast, the Sony A7 III is significantly more robust and sizeable at 127x96x74mm and 650g, nearly doubling the NX20’s weight. That heft is a direct result of a full-frame sensor, rugged construction with weather sealing, and a dense set of controls aimed at demanding photographers.

Ergonomically, the NX20’s smaller grip and fewer physical controls signal a camera geared toward enthusiasts slowly stepping up or hobbyists valuing portability. The Sony, however, makes no compromises: it offers a deep, secure handgrip, extensive button customization, dual card slots, and a weather-resistant magnesium alloy body that withstands challenging environments.

In hand, the NX20 feels nimble and unobtrusive, great for street or casual travel photography; the A7 III’s weight provides stability, especially when paired with heavier lenses, but it also signals a more professional intent.

Control Layout and User Interface: Intuitive or Overwhelming?

Control design can make or break workflow, especially for photographers switching quickly between shooting modes or subjects.

Taking a top-down look (pun intended) reveals the NX20’s clean, simple arrangement of dials and buttons optimized for easy learning curves. It eschews a traditional top screen, relying on its fully articulating OLED screen for settings review.

The Sony A7 III embraces a more complex control suite - dual front and rear command dials, a joystick for focus point selection, customizable function buttons, and a status LCD on top for at-a-glance data. While its complexity might intimidate at first, it rewards mastery with swift, highly efficient operation.

For those valuing tactile control and quick access, the A7 III shines. The NX20 suits beginners or those preferring touchscreen simplicity, although the NX20 notably lacks touchscreen support, relying entirely on physical controls and menus.

Sensor Size and Image Quality: APS-C vs. Full-Frame Revealed

This is where the story gets very interesting. The Samsung NX20 houses a 20-megapixel APS-C CMOS sensor (23.5x15.7mm) with an anti-aliasing filter, while the Sony A7 III uses a 24-megapixel full-frame BSI-CMOS sensor (35.8x23.8mm) that embraces backside illumination, boosting light-gathering efficiency.

What does this mean practically?

• Sensor Area: The A7 III’s sensor is about 2.3 times larger than the NX20’s, providing inherently better noise performance, dynamic range, and depth of field control.

• Dynamic Range: According to DXO Mark data, the NX20 scores 12.9 EVs - respectable for its era - but the A7 III pushes this to 14.7 EVs, a critical improvement for landscapes, HDR, and challenging lighting conditions.

• Color Depth: Both cameras provide strong color reproduction, though the A7 III’s 25-bit color depth edges out the Samsung’s 23.4, subtly improving skin tones and nuanced color accuracy.

• High ISO: Here is where the gap widens dramatically. The NX20 offers usable ISO up to 12800 but with marked noise. The A7 III, benefiting from newer sensor tech and full-frame format, yields usable images even at ISO 51200 native, with extended capabilities to 204800 - more about that later in low-light tests.

Resolution-wise, the Sony outputs 6000x4000 images, slightly larger than the NX20's 5472x3648 pixels, offering more cropping flexibility and print size options.

Rear Screen and Viewfinder: Interfaces for Composition and Playback

The NX20 sports a 3-inch fully articulated OLED screen, with a modest 614k-dot resolution. While the articulation is highly useful for video and creative angles, the screen’s resolution can feel low when reviewing images in detail.

The Sony A7 III features a 3-inch tilting LCD with a higher 922k-dot resolution and touchscreen functionality, facilitating swift focus point adjustment, menu navigation, and image review. Touchscreen responsiveness on the Sony feels particularly precise, aiding operational speed.

Electronic viewfinders illustrate the leap in tech:

• The NX20 offers a basic electronic viewfinder covering 100% frame with approximately 0.7x magnification.

• The A7 III uses a 2.36-million-dot OLED EVF with 0.78x magnification and 100% coverage, delivering near-optical clarity and excellent detail visibility even in bright conditions.

The EVF is critical in bright outdoor shooting, and the Sony’s viewfinder experience is far smoother, reducing eye strain during prolonged shooting - a notable advantage in fast-paced workflows.

Autofocus: Precision, Speed, and Tracking Capabilities

Autofocus systems, arguably the heartbeat of modern cameras, dictate ability across genres - be it nailing wildlife in flight, tracking athletes, or locking focus on a subject in street scenes.

The Samsung NX20 uses contrast-detection autofocus with 15 focus points and face detection, performing well in good light but struggling with fast-moving subjects and low contrast scenarios. It lacks phase-detection AF entirely, limiting responsiveness and AF tracking.

In stark contrast, Sony’s A7 III employs a hybrid autofocus system with 693 phase-detection points alongside 425 contrast-detection points, covering a broad portion of the frame. It implements real-time Eye AF for humans and animals and offers reliable subject tracking, even in dim environments.

This difference manifests clearly when shooting wildlife or sports: the A7 III maintains lock as birds zoom across the sky or players sprint across a field, while the NX20 often hunts or misses entirely in these conditions.

Burst Shooting and Buffer Performance: Freezing the Moment

With 8fps continuous shooting, the NX20 was competitive for its release time. However, limited buffer depth and relatively slow SD card interface can slow workflows, especially shooting in RAW.

Sony A7 III takes it further with 10fps continuous shooting, plus a deep buffer allowing up to 177 compressed RAW or 89 uncompressed RAW frames before slowdown. This capacity facilitates extended bursts necessary in sports, wildlife, or event photography.

Video Capabilities: From Full HD to 4K with Advanced Features

The Samsung NX20 offers Full HD video capped at 1080p/30fps and 720p options. While incorporating H.264 encoding and an external microphone port for better audio, it does not support 4K or advanced codecs. The lack of in-body stabilization can be a drawback for handheld video unless paired with optically stabilized lenses.

Sony A7 III is a significant jump, delivering 4K UHD recording at 30p, plus 1080p at frame rates up to 120fps for smooth slow motion. 5-axis sensor-based stabilization benefits both photo and video, helping create steady handheld shots. The camera supports S-Log profiles, enabling professional-grade color grading, and has both microphone and headphone ports for precise audio control.

For videographers and hybrid shooters, the A7 III’s video performance is a game-changer compared to the NX20.

Lens Ecosystem and Mount Compatibility

The Samsung NX mount supported 32 lenses - a decent variety at the time but limited compared to larger ecosystems. Samsung exited the interchangeable lens camera market years ago, so lens choices remain static and less future-proof.

Sony’s E-mount system, on the other hand, boasts over 120 native lenses, including extensive third-party support from Sigma, Tamron, and Zeiss. This breadth covers everything from ultra-wide primes to super-telephoto zooms, macro, and cinema lenses - a crucial advantage for photographers who want flexibility and scalability.

Battery Life and Storage Solutions

Samsung’s NX20 delivers reasonable battery life with a CIPA rating of about 360 shots per charge. While adequate for casual shooting, this limited endurance can be a hurdle for event or extended fieldwork.

Sony’s NP-FZ100 battery nearly doubles this, rated at 610 shots per charge, with efficient power management and USB charging options supporting longer shoots and on-the-go flexibility.

Storage-wise, the NX20 supports a single SD card slot compatible with SD/SDHC/SDXC cards. The A7 III improves reliability and backup workflows with dual card slots supporting UHS-II SD cards, plus Sony Memory Stick formats.

Connectivity and Modern Features

The NX20 comes with built-in Wi-Fi, USB 2.0, and HDMI output, suitable for casual sharing and tethering but lacks Bluetooth and NFC.

The Sony A7 III adds Bluetooth and NFC alongside Wi-Fi and faster USB 3.1 Gen 1, streamlining wireless transfers, remote control, and tethered shooting with mobile apps - key features for professionals needing seamless integration into modern workflows.

Weather Sealing and Build Durability

The NX20 does not offer environmental weather sealing, so it requires extra care around dust, moisture, and cold.

The A7 III boasts advanced sealing against splashes and light dust, though not fully waterproof or shockproof, allowing confident use in varied weather conditions - a boon for outdoor photographers.

Practical Performance Across Photography Disciplines

Let’s break down how the two cameras match up in real-world shooting scenarios.

Portrait Photography: True-to-Life Skin and Eye AF

The NX20 renders pleasing colors but lacks dedicated eye AF, relying on face detection. Its APS-C sensor creates decent background separation with suitable lenses but cannot rival full-frame’s creamy bokeh.

The A7 III’s advanced eye AF locks focus on the human or animal eye with remarkable precision and speed. Its full-frame sensor delivers superior dynamic range to preserve subtle skin tones and produces luscious background blur even with moderate telephoto primes.

Landscape Photography: Dynamic Range and Resolution Matter

Thanks to its larger sensor and higher dynamic range, the A7 III captures shadow and highlight detail with more nuance, important for high-contrast scenes like sunrises or forests with dappled shade.

The NX20 can produce sharp landscapes but may struggle with clipping and noise in shadows or highlights. Its weather sealing limitations also mean caution in harsher weather.

Wildlife and Sports Photography: Tracking Speed and Burst

The A7 III is the clear favorite - its hybrid AF system, 693 phase-detect points, real-time subject tracking, and rapid 10fps burst align for success chasing birds in flight or fast-moving athletes.

The NX20’s slower contrast-only AF and 15 focus points make it less adept in these fields, best suited to static or slower subjects.

Street Photography: Discreetness and Agility

Compact and lightweight, the NX20’s modest weight and size make it less conspicuous for candid street work; its quiet shutter and flip screen aid compositional creativity.

The Sony is bulkier and heavier, which might draw attention and fatigue during prolonged shoots, but its superior autofocus and low-light performance compensate if size is less a concern.

Macro Photography: Focusing Precision and Stabilization

Neither camera has native macro capability built-in, so lens choice and focusing methods matter here.

The NX20 lacks in-body image stabilization (IBIS), relying on stabilized lenses or tripods. The A7 III’s 5-axis IBIS allows sharper handheld macro shots, while its precise AF and focus peaking assist careful manual focus work.

Night and Astrophotography: High ISO and Noise Control

This is where the A7 III displays its full-frame advantage. Its BSI sensor and low-light ISO rating above 3700 deliver cleaner images at high ISOs, essential for star fields and dim landscapes.

The NX20’s APS-C sensor produces notably more noise in low-light, limiting its astrological use primarily to brighter night scenes or static, long-exposure tripod work.

Video: Professional Quality Meets Usability

The A7 III offers 4K video with S-Log color profiles, advanced autofocus during recording, and superior stabilization - a combination that appeals to pros and content creators alike.

The NX20’s Full HD max resolution and lack of image stabilization limit its video appeal to casual use.

Travel Photography: Versatility and Battery Life

For traveling light, the NX20’s compact size and articulated screen shine, alongside ample lens options for its form factor.

The A7 III, while heavier, offers unmatched versatility, superior battery life, and professional features like dual card slots and better weather resistance - valuable for longer, varied trips.

Reliability and Professional Workflow Integration

The A7 III’s robustness, dual card slots, superior buffer, and compatibility with Sony’s expansive professional lens line make it a viable tool for daily demanding professional use.

The NX20, while well-built for its time, fits best as a capable enthusiast camera or backup body now.

Samsung NX20 front Samsung NX20 screen back Sony A7 III front Sony A7 III screen back

Summarizing Performance Ratings and Value

Bringing together technical benchmarks, autofocus prowess, image quality, and versatility:

While the Samsung NX20 was a strong APS-C contender in 2012, the Sony A7 III stands as a much more capable, mature machine with scores reflecting significant advances, especially for demanding users.

Genre-specific evaluations echo this pattern:

Final Verdict: Who Should Buy Which?

Consider the Samsung NX20 if:

• You prefer a lightweight, compact APS-C camera for casual street, travel, or portrait photography.
• Your budget is around $1000 or less, and you do not require 4K or rapid autofocus.
• You value an articulated OLED screen for video or creative composition angles.
• You already own Samsung NX lenses or find them second-hand bargains.

Opt for the Sony A7 III if:

• You need a professional-grade, versatile full-frame mirrorless camera with excellent low light, autofocus, and video capabilities.
• Your photography spans demanding disciplines, including wildlife, sports, or extensive landscapes.
• You require reliability, weather sealing, dual card slots, and future lens investment possibilities.
• You seek hybrid photo/video performance with 4K recording and advanced connectivity.

This side-by-side reflects how mirrorless camera design and performance evolved dramatically between 2012 and 2018. While the NX20 holds nostalgic charm and remains capable for specific uses, the Sony A7 III’s technological edge caters comprehensively to today’s diverse photographic ambitions.

Should you choose to invest in the Sony A7 III, expect a tool that will carry you through professional assignments and passionate creative projects alike. And if portability and simplicity top your list, the Samsung NX20 still offers an engaging experience that many will find enjoyable.

As always, selecting a camera is deeply personal - I encourage hands-on testing where possible and careful consideration of the lenses that will accompany your journey. Happy shooting!