Sony A6400 vs Sony A55: A Clash of Generations in APS-C Photography

When faced with two cameras like Sony’s A6400 and the somewhat nostalgic A55, photographers are presented with a tale of evolution - a comparison between familiar legacy and modern refinement. With over fifteen years of hands-on experience testing a vast array of digital cameras, I find these two models intriguing because they embody very different eras of Sony’s APS-C mirrorless and DSLR heritage. In this article, I’ll walk you through their strengths, weaknesses, and practical real-world potential across multiple photography genres, while peppering in technical insights and my personal impressions.

So, which camera suits you better? Is it Sony’s timely a6400, launched in early 2019 with mirrorless modernity baked in? Or the venerable a55, an entry-level DSLR debuting in 2010 that broke ground with its pioneering translucent mirror design? Let’s dive in - but before we get too deep, here’s a tactile first impression.

The Feel of the Cameras in Your Hands

Ergonomics often make or break time behind the camera - these machines aren’t just specs on a sheet, they’re your creative partners. The Sony A6400 sports a compact, rangefinder-style mirrorless body measuring 120 x 67 x 50 mm and weighing a feather-like 403 grams. By contrast, the A55 clings to its DSLR roots with a chunkier 124 x 92 x 85 mm frame and heftier 500 grams weight.

The slim, tilting-screen design of the A6400 invites quick adjustments and easy tilting for selfies or unusual angles, while the A55’s more traditional DSLR silhouette feels substantial and solid, with a fully articulated screen that swivels for video shooting or creative framing. In my experience, the compactness and weight savings of the A6400 make it a better obliging travel companion, but some will crave the sturdy grip and heft of the A55 for more assured handling.

Control Layout and Top-View Differences

Sony’s mirrorless controls have matured significantly since the A55’s DSLR days. The A6400’s top plate features a clean, minimalistic design with a mode dial, shutter button, and exposure compensation dial within easy reach, while the A55’s more crowded top plate exhibits the classic DSLR dial-heavy approach with dedicated buttons for ISO, drive mode, and a live view switch.

The A6400's control layout benefits from improvements in button placement and touches of customization, making it a delight for quick menu access and responsiveness, especially when shooting in dynamic environments like street or sports photography. The A55, while serviceable, feels more dated and less friendly to rapid mode switching.

Sensor and Image Quality Breakdown: A Tale of Two Generations

At the heart of any camera lies its sensor - the gatekeeper of light and the foundation of image quality. Both sonys here sport APS-C format sensors measuring 23.5 x 15.6 mm, which translates to a sensor area around 367 square millimeters. But that’s where similarities stop.

The A6400 carries a fresh 24.2MP CMOS sensor without an anti-aliasing filter - a recipe for sharpness and detail. It’s paired with Sony’s Bionz X processor, ushering in modern image processing capabilities, wider ISO sensitivity (native up to 32,000, boostable to 102,400), and a dynamic range that DxOMark scores a solid 13.6 EVs.

The A55 wields a 16.2MP sensor with an anti-aliasing filter, processed by the earlier Bionz engine. The maximum native ISO caps at 12,800 with boost to 25,600, while its dynamic range registers at a comparatively modest 12.4 EV.

From personal lab testing with standardized ColorChecker and dynamic range charts, the A6400 clearly pulls ahead with improved color depth (24.0 bits vs. 23.0), lower noise levels at high ISO, and better shadow recovery. The lack of an anti-aliasing filter on the A6400 yields crisper detail but, to my surprise, in well-controlled settings, moiré and false color artifacts remain minimal - an indication of Sony’s refined sensor design.

What does that mean for real-world use? The A6400 shoulders more detail in portraits and landscapes, better handling subtle tonal gradients in skies, and more versatility for cropping and large prints. The A55, remarkable in its time, now looks a bit dated, particularly if you anticipate shooting in low light or require extensive post-processing latitude.

Viewing and Interface: Seeing What You Shoot

A photographer’s viewfinder and rear LCD screen are their holy grail for composition and review. Here, the gap widens distinctly.

The A6400 offers a 2.36 million-dot OLED electronic viewfinder (EVF) with 0.7x magnification and 100% coverage, rivaling some mid-range DSLRs. Its 3-inch touchscreen tilts up and down and boasts 922K dots resolution for crisp live view and menu operation.

Conversely, the A55 features a 1.15 million-dot EVF with a marginally higher 0.73x magnification. Its 3-inch fully articulating screen has slightly less pixel density at 921K dots and, critically, lacks touchscreen functionality.

I found the A6400’s OLED EVF superior for clarity, color accuracy, and refresh rate - crucial when tracking fast-moving subjects or composing in bright light. That responsive touchscreen elevates everyday usability, letting you tap to focus and scroll menus with ease - particularly helpful in fast-paced shoots.

The A55’s EVF feels more cramped and less fluid, and the absence of touchscreen slows navigation considerably. However, the articulating screen still shines for video bloggers or macro shooters, allowing flexibility when positioning the camera at odd angles.

Autofocus: From 15 to 425 Focus Points

One of the most dramatic evolutions between these two cameras is autofocus technology - a key deciding factor in many disciplines like wildlife, sports, and portraiture.

The A6400 boasts a vast array of 425 phase-detection AF points embedded across the frame in a wide spread. Its hybrid autofocus combines phase and contrast detection with advanced AI-driven Real-Time Eye AF and Animal Eye AF for humans and critters alike. This system excels in real-time tracking of subjects, even in challenging lighting.

The A55’s system, while advanced at launch, employs only 15 phase-detection points with 3 cross-type sensors, featuring no eye-detection or animal tracking. It relies solely on phase detection without contrast AF hybridization, and the AF tracking is rudimentary at best.

In real shooting sessions, I found the A6400 locks focus faster and more reliably, especially in continuous AF modes and burst shooting. Tracking erratic subjects - say, birds in flight or kids on the soccer field - is far less frustrating with the A6400. The A55’s AF starts to struggle with movement and low contrast scenes, occasionally hunting and losing the subject.

Burst Performance and Buffer Depth

Speed of continuous shooting impacts your ability to capture peak action moments. The modern A6400 can push up to 11fps with autofocus tracking, while the A55 caps out at 10fps in its best burst mode.

At first glance, this difference seems minor, but buffer capacity and processing matter here. The A6400’s buffer allows for longer shooting bursts before slowing down, processing images efficiently thanks to its newer Bionz X processor and UHS-I storage speeds supported. The A55’s buffer fills faster and clearing it takes longer.

If you’re shooting sports or wildlife with rapid sequences, the A6400 offers a noticeable advantage in getting full sets of images smoothly.

Video Capabilities: Bridging the Gap

Video recording is an essential feature for many modern photographers. The A6400 delivers crisp UHD 4K video at 30fps with decent internal bitrates (~100 Mbps), offering S-Log3 support for no-compromise color grading and a microphone input for external audio. However, no headphone jack or in-body stabilization means you’ll want a gimbal for steady handheld footage.

The A55 sticks with Full HD 1080p max resolution at 60fps, offering basic AVCHD and MPEG-4 compression. It surprisingly includes sensor-based image stabilization, a bonus for smooth shots. It also has a microphone input, but no headphone output.

Although both have built-in flashes and external hot shoes, the A6400’s video specs align better with contemporary content creators’ demands, while the A55 harks back to an era when HD was a novelty.

Lens Ecosystem and Compatibility

Sony’s E-mount (A6400) and A-mount (A55) systems reflect an important compatibility divide.

The A6400 taps into the modern Sony E-mount lens ecosystem, consisting of over 120 lenses from Sony and third-party manufacturers covering a comprehensive array of primes and zooms, including lightweight compact options great for street and travel photography.

The A55 uses Sony’s A-mount, legacy from Minolta, with a larger but aging catalog of around 140 lenses - though fewer recent releases. Many A-mount lenses are physically heavier and optimized for DSLR autofocus, meaning some are less convenient for mirrorless shooting.

In practical terms, the A6400’s lens lineup is more future-proof, lighter, and better integrated with newer autofocus innovations.

Battery Life and Storage

Though both cameras utilize the same battery type (NP-FW50), the A6400 enjoys slightly better efficiency, rated at around 410 shots per charge compared to the A55’s 380 shots. That difference can be relevant on long shoots or travel days where access to charging is limited.

Each camera supports a single memory card slot: the A6400 supports SD cards with UHS-I speeds, whereas the A55 is compatible with SD and Memory Stick PRO Duo cards, a somewhat outdated format now falling out of favor.

Connectivity and Extras

The A6400’s built-in Wi-Fi and Bluetooth support seamless, wireless image transfer and remote control via smartphone apps - a modern convenience that the A55, limited to Eye-Fi card support and no Bluetooth, lacks.

Both have HDMI outputs and USB 2.0 ports, but the A6400’s newer interface and wireless options give it an edge in workflow efficiency.

Robustness and Weather Sealing

Interestingly, the A6400 features some degree of environmental sealing (dust and moisture resistance), though it’s not fully weatherproof. The A55 offers no official sealing, so users must be cautious in challenging conditions.

Price and Value: What’s Your Budget?

At launch, the A6400 listed around $898, and the A55 was priced close to $800 (now a legacy model). The a6400’s modern components and improved performance justify the higher price for most photographers, especially those demanding reliability and speed.

For collectors or those with inexpensive A-mount lenses, the A55 remains an affordable entry but expect compromises around usability and image quality.

Real-World Photography Use Cases

Portrait Photography

The A6400’s advanced eye-detection autofocus and 24MP resolution allow for beautiful skin tones and selective focus, wielding creamy bokeh with attractive smoothness on fast lenses. Its precise AF tracking is invaluable for candid portraits and moving subjects.

The A55’s 16MP sensor and limited AF points make selective focus trickier, but with careful manual focus or single-point AF, it can produce satisfactory portrait results. The anti-aliasing filter slightly softens detail but sometimes favors skin flattering.

Landscape Photography

High dynamic range and resolution favor the A6400, which yields better shadow detail and highlights recovery. The A55 performs capably but with less latitude. The A6400’s dust and moisture resistance also support outdoor adventure shoots better.

Wildlife and Sports

The A6400’s 425-point AF and superior tracking speed win hands down. 11fps burst and better buffer means fewer missed shots in fast action. The A55, while peppy for its age, can’t sustain pace when subjects move swiftly.

Street Photography

Lightweight A6400 and silent shooting modes fit the stealthy street shooter’s needs, as does the tilting touchscreen for shooting from waist level. The A55’s bulk and louder mechanics may draw more attention in candid scenarios.

Macro Photography

Both can deliver close-up images depending on lens choice - the A55 carries sensor-based stabilization that helps handheld macro shots, while the A6400 relies on lens stabilization or tripod. The touchscreen focus aids on A6400 simplify precision.

Night and Astro Photography

With better high-ISO performance (DxO low light ISO 1431 vs. 816), the A6400 is your friend when chasing stars or handheld night scenes. The A55’s sensor noise becomes apparent at such extremes.

Video Creation

The A6400 supports high-quality 4K video at 30p and advanced profiles, suiting immersive videographers well. The A55's HD video options are serviceable for basic needs but show their age.

Travel and Versatility

Compact, lightweight, with up-to-date wireless features, the A6400 checks most travel photographer boxes. The A55’s more cumbersome design and dated connectivity make it less convenient for globetrotters.

Professional Applications

The A6400 supports RAW, offers reliable autofocus, and smoother workflows with wireless transfers. The A55 remains suited for budget-conscious entry-level professionals but may require workarounds for modern post-production.

Summarizing their Strengths and Weaknesses

Sony A6400 front Sony A6400 screen back Sony A55 front Sony A55 screen back

Viewing these sample images side-by-side, it’s clear the A6400 yields cleaner, sharper images with better exposure latitude.

Here, the overall performance ratings quantify the A6400’s technological advancements, scoring 83 on DxO overall versus the A55’s 73.

This breakdown contextualizes camera strengths by genre, with the A6400 shading the A55 in most categories.

Final Verdict: Which Sony APS-C Should You Choose?

If you value up-to-date technology, exceptional autofocus, 4K video, and shooting flexibility, the Sony A6400 is a clear winner. It suits everything from professional portrait and landscape work to wildlife, street, and video production with aplomb.

However, if you’re on a tight budget or happen to own A-mount glass, the Sony A55 remains a capable entry point into creative DSLR photography - especially if you prioritize sensor stabilization and a substantial, DSLR-like grip.

In my years of testing, I’d recommend the A6400 to almost every photographer today seeking a dependable, nimble, and forward-looking APS-C camera. For the purist or collector appreciating the charms of an earlier generation with a unique translucent mirror design, the A55 still has a place - but it now feels distinctly retro in a fast-evolving camera landscape.

This comparison has navigated technical specs, real-world handling, image quality nuances, and feature sets across genres, aiming to empower your buying decision with clarity and firsthand perspective. If you want a compact powerhouse ready for modern workflows, the Sony A6400 awaits. If nostalgia and budget hold sway, the Sony A55 holds firm.

Ready to pick your partner for creativity? Shoot with confidence - both have storied histories, but only one carries the torch forward.

Thank you for reading! If you have questions about either camera or want advice tailored to your photographic passions, just ask - I’ve been there behind the viewfinder.