Samsung GX-20 vs Sony A6400: A Deep Dive Into Two APS-C Titans Spanning a Decade

In the age of hyper-rapid camera innovation, it's a rare treat to pit a venerable DSLR classic from 2008 against a cutting-edge mirrorless marvel from 2019. The Samsung GX-20 and Sony A6400, both APS-C cameras embody vastly different eras and philosophies - one a solid, traditional DSLR offering robust manual control, the other a tech-dense, lean mirrorless machine bursting with autofocus wizardry and video prowess.

As someone who's tested countless cameras over 15 years in studios, landscapes, sports arenas, and everything in between, this comparison isn’t just a specs face-off but a reflection on how camera technology has evolved - and what each model offers you as a photographer or videographer today.

Grab a coffee, maybe stack those two cameras side-by-side - and let's unpack their quirks, strengths, and quirks that could sway your buying decision.

First Impressions: Size, Build, and Handling – Do You Want a DSLR or Mirrorless Feel?

Handling and ergonomics are the unsung heroes of photography enjoyment. A great sensor and processor mean zilch if the camera feels awkward in your hands or the controls aren’t intuitive.

The Samsung GX-20 is a mid-sized DSLR with a solid, traditional SLR form factor reminiscent of Pentax heritage - sturdy but weighty at 800 grams and chunkier dimensions (142x101x72 mm). Its pentaprism viewfinder and robust build scream reliability. The camera’s heft lends it stability, but if you’re prone to neck cramps on long walks or shoots, it might tire you out.

On the other hand, the Sony A6400 - a lean, rangefinder-style mirrorless - is a lightweight wonder at just 403 grams with compact dimensions around 120x67x50 mm. It slips easily into a jacket pocket or small bag, making it a formidable travel companion. The trim profile doesn't sacrifice grip comfort notably, thanks to a thoughtfully shaped handgrip despite the smaller body.

Handling preferences aside, ergonomics extend beyond size.

The GX-20 showcases classic DSLR controls: dedicated dials for shutter speed, exposure compensation, drive modes, and a top LCD panel - allowing tactile adjustments without toggling menus. As someone who often shoots outdoors with gloves, these physical knobs make changes feel seamless and immediate.

Conversely, the A6400 goes for minimalism with fewer physical dials, relying more on customizable buttons and touchscreen interface. The tilting 3" LCD screen with touch sensitivity is a boon for versatile shooting angles and quick selective focusing. The GX-20’s fixed, non-touch 2.7” screen feels cramped and less interactive by comparison.

So, it boils down to your control style preference: do you want DSLR-like dials and heft or compactness with touchscreen flexibility?

Sensor and Image Quality: Old School vs New Breed APS-C

Sensors are the beating heart of image quality, and here the Sony A6400 unmistakably sets a higher bar.

Both cameras employ APS-C sensors of very similar physical size (~23.5x15.6 mm), maintaining the customary 1.5x crop factor, but the Sony packs a higher resolution at 24 megapixels, versus the Samsung’s 15 megapixels. That translates to larger images with more detail for cropping or big prints.

On image quality metrics from DxOMark testing, the A6400 significantly outperforms the GX-20 across all categories:

• Overall score: Sony A6400 with 83 vs Samsung GX-20 at 68
• Color depth: 24.0 bits vs 23.1 bits (a subtle but noticeable difference, especially in skin tones and subtle gradients)
• Dynamic range: 13.6 EV vs 11.2 EV - The Sony captures more nuanced shadow and highlight detail
• Low light ISO performance: 1431 ISO vs 714 ISO - Nearly double the usable ISO, critical for night and indoor photography

The Sony’s sensor benefits from nearly a decade of technological refinement - backside illumination, improved microlenses, and better noise filtering - meaning cleaner images at higher ISO and wider tonal latitude.

The Samsung’s CMOS sensor, while respectable for its time, shows higher noise levels beyond ISO 800 and loses detail in shadows quicker. For landscape photographers who prize dynamic range or portrait shooters craving rich skin tones, the Sony holds a distinct edge.

Autofocus System: Tracking Moving Subjects in a Snap or a Lag?

One of the most dramatic leaps from the GX-20 to the A6400 lies in autofocus technology. And yes, having tested everything from film-era manual focus to today’s blazing AF systems, the difference is night and day.

The Samsung GX-20 offers:

• 11 autofocus points (good but limited)
• Phase detection AF, no face or eye detection
• Continuous AF at 3 fps shooting speed

The Sony A6400 raises the stakes with:

• 425 phase-detection AF points covering nearly the entire frame
• Real-time Eye AF for humans and animals (game changer for portraits and wildlife)
• Tracking AF that adapts to moving subjects
• 11 fps continuous shooting with AF tracking

This is not just a numbers game. I tested both cameras shooting fast-moving subjects (soccer matches and birds in flight).

The GX-20’s AF hunts more frequently and often struggles to lock accurately on erratic movement, leading to missed shots or less sharp results. In contrast, the A6400 practically reads your mind - instantly locking, tracking, and refocusing even in chaotic scenes with impressive reliability.

If you photograph sports, wildlife, or any fast-action, the Sony’s autofocus system will save you countless frustrating moments.

Viewfinder and Display: See Clearly to Shoot Sharply

I’m old enough to still appreciate the optical clarity of pentaprisms - but technological progress has made electronic viewfinders very compelling.

The Samsung GX-20’s viewfinder is optical, covering 95% of the frame at 0.64x magnification. While bright and with zero lag, it doesn’t provide 100% coverage, so some composition guessing is needed. The LCD is fixed at a modest 2.7" with 230k dots - a bit small and low-res by modern standards.

Sony’s A6400 offers a high-res 2.36 million dot electronic viewfinder with 100% coverage and 0.7x magnification, providing an accurate, bright, and detailed preview of exposure, white balance, and focus peaking. For environmental portraiture or landscapes, this clarity is invaluable.

The Sony’s 3" tilting touchscreen gives you framing options, selfie-friendly flips, and touch-to-focus - especially handy for trickier angles. Samsung’s LCD doesn’t move or respond to touch, locking you into standard eye-level framing.

Video Capabilities: From Still Shooter to Moving Image Maker

The Samsung GX-20 is firmly a stills camera in terms of video - it offers no video recording capabilities. That’s perfectly fine for purists or those primarily shooting photographs, but in today’s multimedia world, video is nearly ubiquitous.

The Sony A6400, on the other hand, provides solid 4K video (3840x2160 @ 30fps) encoded in high-quality XAVC S codec. It has:

• Built-in microphone jack for better audio capture
• Advanced autofocus with continuous tracking in video mode
• Exposure and white balance adjustments during filming
• Slow and rear-sync flash modes for hybrid shooters

Having used the A6400 for both short films and event recordings, I can attest its video quality punches well above its class. The absence of in-body image stabilization is a minor downside, but reasonable lens stabilization and gimbals compensate well.

Weather Sealing and Durability: Ready for the Field?

Surprisingly, both cameras offer weather sealing components - not foolproof waterproofing, but better than many counterparts.

The GX-20 has sealing around dials and joints, making it a dependable companion in damp or dusty conditions. The Sony A6400 also includes some environmental sealing, especially around the mount and battery compartments, bolstering confidence outdoors.

Neither model is shockproof or freezeproof, so caution is still warranted in extreme conditions.

Lenses and Accessories: What’s in the Ecosystem?

Samsung’s GX-20 uses the Pentax KAF2 mount, compatible with an extensive but aging lineup of 151 lenses. For vintage lens lovers or Pentax enthusiasts, there’s a treasure trove, albeit mostly manual focus and older optics.

Sony’s E-mount ecosystem is vibrant and growing exponentially, with 121 native lenses at release and many more third-party options from Sigma, Tamron, and Zeiss - all with autofocus support. From affordable primes to pro-level zooms, the selection suits virtually any genre.

If lens variety, modern AF optics, and video-friendly lenses matter to you, the Sony system is more future-proof.

Battery Life and Storage: How Long Can You Shoot?

Battery-wise, the Sony A6400 offers around 410 shots per charge with the NP-FW50 battery - typical for mirrorless systems but on the modest side. The GX-20’s battery capacity isn’t specified here, but older DSLRs usually offer longer endurance.

Both cameras store images on SD cards - Samsung supports SD, MMC, and SDHC types; Sony expands compatibility to SDXC and Memory Stick DUO.

For extended outings, carrying extra batteries is advisable with the Sony, while the bulkier GX-20 may surprise you with better longevity.

Shooting Experience Across Genres: What Fits Your Passion?

Now for my favorite part - how these cameras perform across the wide range of real-world shooting scenarios.

Portrait Photography

The Sony A6400 leaps ahead with its high resolution, excellent color depth, and industry-leading Eye AF that locks onto and tracks eyes in real time - even animal eyes - delivering tack-sharp portraits effortlessly. The ability to shoot at higher ISOs with cleaner results lets you capture flattering skin tones in varied lighting without crawling for a tripod.

The GX-20, while capable, lacks face/eye AF and lower resolution means less cropping flexibility. Its lower dynamic range also compresses tonal gradations, demanding more post-processing skill.

Sony is the clear winner for portraits if you want fast and fuss-free results.

Landscape and Nature

Dynamic range and resolution matter most here, along with weather sealing and battery life.

The 13.6 EV dynamic range advantage makes the Sony better able to retain detail across bright skies and dark shadows. The higher 24MP sensor provides ample resolution for large prints.

However, the GX-20’s slightly larger battery and optical viewfinder might be more comfortable on long hikes for some. Despite its age, it held up reasonably well in wet and cold conditions in my tests.

For landscape pros who want cutting-edge image quality, Sony is preferable; traditionalists valuing rugged feel may still appreciate the Samsung.

Wildlife and Sports

Here autofocus speed, tracking, and burst rate dominate.

The A6400’s 425-point Eye AF, 11 fps shooting with continuous AF, and compact form factor give it a massive edge in freezes-fast-action scenarios.

The GX-20’s 3 fps and limited 11-point AF can lead to missed moments in chaotic wildlife action or sports.

No contest: Sony takes the win for serious sports and wildlife photographers.

Street and Travel

The Sony’s small size, lightweight body, silent shutter, and quiet but fast AF make it perfectly suited for candid street work and travel. The tilting touchscreen helps capture shots from odd angles without attracting attention.

The GX-20, bigger and heavier, is less discreet and more conspicuous.

Macro and Night/Astro Photography

Macro shooting benefits from precise manual focusing and image stabilization, which the GX-20 offers with sensor-shift IS, providing an advantage over Sony’s lack of IBIS (in-body image stabilization).

For night/astro, the Sony’s higher ISO performance and higher resolution sensor offer cleaner, sharper images, crucial when pushing exposure limits.

Professional Work and Workflow

Sony’s support for modern RAW formats, 14-bit files, and seamless connectivity with wireless transfer and USB 2.0 aids professional workflows.

Samsung’s lack of built-in wireless connectivity feels archaic in 2024's workflow ecosystem.

Pricing and Value: What Are You Really Paying For?

At launch, the GX-20 priced around $850, now only found used, offers entry into DSLR photography’s golden era, albeit with some limitations by today’s standards.

The Sony A6400 remains competitively priced around $900 new, given its rich feature set, making it an outstanding value for enthusiasts wanting a versatile all-rounder.

Samsung GX 20 front Samsung GX 20 screen back Sony A6400 front Sony A6400 screen back

Comparing sample image galleries, the Sony’s files provide more detail, better color rendering, and cleaner noise profiles at higher ISO - evidence the sensor and processor improvements translate to tangible photography advantages.

This chart encapsulates the height difference in scoring between these cameras - Sony dominating most categories.

It’s visible the A6400 rates superior across portrait, landscape, sports, wildlife, and video disciplines.

Final Thoughts: Which Should You Buy?

If you value solid, traditional DSLR experience, tactile dials, sensor-based image stabilization, and a DSLR optical viewfinder with a vintage Pentax lens system - especially if budget is constrained or you treasure manual control and don’t need video - then the Samsung GX-20 might charm you.

However, if you want speed, accuracy, modern connectivity, superb autofocus including eye tracking, excellent video modes, light portability, and superior image quality with a thriving lens ecosystem, the Sony A6400 is the camera I reach for again and again.

For beginner or enthusiast travelers, street photographers, and hybrid photo/video users: Sony is the smarter investment.

For enthusiasts who want a classic DSLR experience, enjoy manual control, and dabble in rugged still photography without fuss: Samsung remains a valid, affordable choice - especially if you can find one in good condition.

In short: Technology marches on, but your photographic vision and needs dictate the right tool. Both cameras have stories to tell - and so will you, whichever you choose.

Happy shooting!