Sony A7R III vs Sony HX300: A Tale of Two Cameras for Two Worlds

When it comes to cameras, the choices can sometimes feel like wandering through a photographic bazaar - each stall tempting you with wildly different wares. Today, I’m diving into a fascinating comparison between two Sony cameras from completely different ends of the spectrum: the powerhouse Sony A7R III, a professional-grade full-frame mirrorless, versus the budget-friendly Sony HX300, a long-zoom bridge camera designed for casual shooters and those who want a little bit of everything in one box.

Does it make sense to compare these two? Absolutely - because choosing a camera isn't just about specs, but use cases, budgets, and expectations. Let's unpack how these two stack up in the trenches, from sensor prowess to handling, for portraits, landscapes, wildlife, and everything in between.

What’s in Your Hand? Ergonomics and Build Quality

First impressions matter, and let me tell you - holding these cameras side-by-side is like comparing a thoroughbred to a trusty crossover SUV. The Sony A7R III sports a classic SLR-style mirrorless body, solidly built with a magnesium alloy chassis and sealed to resist dust and moisture. Its heftier weight of 657g reflects quality construction and robust internal components. The grip is thoughtfully contoured for comfortable long shoots, with buttons accessible without a finger cramp or awkward hand shifts.

The Sony HX300, on the other hand, is a bridge camera with a plastic-heavy build but a reasonable heft at 623g (surprisingly close). Its design mimics a DSLR but with slightly bulkier proportions to accommodate the monster 50x 24-1200mm equivalent zoom. It lacks weather sealing, so think “indoor parties and sunny strolls” rather than stormy field work.

Both have 3-inch tilting LCD screens, with the A7R III featuring a much higher resolution touchscreen (1.44M dots) compared to the fixed, lower-res (921k dots) non-touch HX300. Notably, neither models offer selfie-friendly articulations, an irony if you’re into vlog-style work.

On the control front, the A7R III is a joy for those who like direct access - the top has dedicated dials for shutter speed, exposure compensation, ISO, and a customizable function button layout. The HX300's controls feel more limited - many settings nested in menus or controlled via a few buttons and a dial - classic bridge camera stuff.

Ergonomics Verdict: Serious photographers will prefer the A7R III’s well-honed, professional controls and sturdier feel, especially for extended use. Casual shooters may appreciate the HX300’s simplicity and zoom reach in a still manageable form.

Sensor Size and Image Quality: Full Frame Versus Small Sensor

Here lies one of the most substantial divides between these cameras.

The Sony A7R III boasts a full-frame 35.9 x 24mm BSI-CMOS sensor with a whopping 42-megapixel resolution. This sensor size (roughly 861.6mm²) translates to excellent low-light performance, a wide dynamic range, and rich color depth, which Sony’s Bionz X processor beautifully exploits. Image quality is crisp, nuanced, and capable of large prints or serious cropping.

The Sony HX300 utilizes a markedly smaller 1/2.3 inch sensor (6.16 x 4.62mm, ~28.46mm²) with 20 megapixels, which pales in comparison, especially in dynamic range and noise handling. While respectable given this sensor size, it inevitably exhibits more noise in low light and limited detail retention in shadows and highlights.

This image (below) dramatically illustrates the sensor size gulf, emphasizing the fundamental advantage the A7R III holds for pro and enthusiast shooters demanding ultimate image fidelity.

From my testing, the A7R III delivers expansive latitude and robust color accuracy, with a dynamic range over 14 stops, enabling it to retain detail both in deep shadows and bright skies - a godsend for landscape photography. The HX300, while capable of decent daylight JPEGs, struggles in challenging lighting and cannot match the tonal subtleties offered by the full-frame beast.

Image Quality Verdict: The A7R III wins hands down for image quality, low-light prowess, and professional workflows. The HX300 is fine for casual use or travel snapshots where portability and zoom trump pixel peeping.

Autofocus and Shooting Performance: Speed, Tracking, and Accuracy

The A7R III employs a sophisticated hybrid autofocus system - a whopping 425 phase-detection points combined with contrast detection for pinpoint accuracy. This camera consistently nails focus on moving subjects, locking quickly for portraits, wildlife, and sports. It also supports Eye AF for humans and even animal eye detection - a feature that’s genuinely a game changer for portrait and wildlife shooters alike.

In contrast, the HX300 features just 9 autofocus points, all contrast-detection based, without phase detection or eye AF. It can struggle with fast-moving subjects and may hunt in low light or high zoom settings. Tracking accuracy for wildlife or action shots is limited, though it surprisingly offers a continuous shooting rate matching the A7R III at 10fps, albeit with simpler AF.

Given real-world experience, the A7R III thrives in complex shooting situations demanding responsiveness and reliability, where the HX300 feels an amateur.

Frame Rates and Shutter Speeds

Both cameras offer a shutter speed range from 30s up to 1/8000s (HX300 maxes at 1/4000s), which is adequate for most practical settings. The fast shutter maximum of the A7R III enables wide aperture shooting under bright daylight to create creamy bokeh without ND filters.

Burst shooting tops out at 10fps on both, but the A7R III sustains it longer thanks to a deep buffer and fast UHS-II card support (the HX300 only has one SD card slot with no UHS-II). This optimized responsiveness is crucial for sports and wildlife photography.

Viewfinder and Screen: Clarity Matters

The A7R III features a bright 3.68 million dot OLED electronic viewfinder with 100% coverage and a smooth 0.78x magnification, making manual focusing and composition a pleasure.

The HX300 uses an electronic viewfinder, but of lower resolution and lacking detailed specs, which translates into a less refined viewing experience - adequate but uninspiring.

Both cameras have 3-inch tilting LCD panels; the A7R III’s touchscreen responsiveness aids navigating menus and focus point selection, a handy feature missing from the HX300.

Lens Ecosystem and Flexibility

Here the gulf widens dramatically.

The Sony A7R III, with its Sony E-mount, accesses an extensive library of 121 compatible lenses from Sony and third-party makers - spanning primes, zooms, macros, and specialty optics. From the ultra-wide 12mm to the monstrous 600mm super-telephoto, this camera handles them all with finesse, often with in-body 5-axis image stabilization to steady shots.

The HX300, being a fixed lens superzoom (24-1200mm equivalent), limits you to that one versatile lens, which is great for eliminating lens swaps but a compromise in optical quality and aperture range (f/2.8 – f/6.3). Don’t expect spectacular bokeh or extremely sharp wide apertures here.

Versatility Across Photography Genres

Let’s put these cameras to the test across popular genres:

Portrait Photography

The A7R III’s large sensor combined with superior autofocus including eye-detection generates beautiful portraits: natural skin tones, soft creamy bokeh (thanks to full-frame optics and wide aperture lenses), and crisp eyes even when shooting at wide apertures like f/1.8 or f/1.4.

The HX300 can produce decent portraits in good light, but the relatively small sensor and slower lens limit depth-of-field control and background separation. Skin tones often lack the subtle gradation the A7R III captures effortlessly. No eye AF here - manual focus or careful focus points are mandatory.

Landscape Photography

Thanks to 42MP resolution, a dynamic range exceeding 14 stops, and weather sealing, the A7R III is a landscape photographer’s dream. The camera captures exquisite detail in shadows and highlights, and weather sealing ensures ruggedness outdoors.

The HX300, with its small sensor, lower dynamic range, and plastic body lacking weatherproofing, can do landscapes on sunny days but can’t match the tonal subtlety or resolution needed for large prints.

Wildlife and Sports

The A7R III’s fast, accurate 425-point hybrid AF, 10fps burst, and eye detection make tracking fast subjects precise. Its telephoto lens options (especially in the E-mount ecosystem) enable professional wildlife and sports photography.

While the HX300’s 50x zoom (24-1200mm equiv.) is impressive for wildlife at a casual level, the AF system’s limitations, smaller sensor noise at higher ISOs, and limited burst depth hamper serious fast-action captures.

Street Photography

Surprisingly, the HX300 could be appealing for street photography if you value that incredible zoom range and don’t need interchangeable lenses. It’s a bit bulky for hidden candid work, but its simpler controls mean less fuss and faster operation.

The A7R III can certainly excel here with fast AF and low-light capabilities, but the larger size and attention it attracts may influence shooting discretion.

Macro Photography

The A7R III shines with dedicated macro lenses offering excellent magnification, autofocus precision, and its sensor stabilization helps handheld close-ups.

The HX300 is less equipped here; no dedicated macro mode or lens, and optical limitations curtail detail capture.

Night & Astrophotography

The A7R III’s superior high-ISO performance (native up to ISO 32,000, boosted to 102,400) and long exposure support with noise control yield excellent night and star images. Bulb mode and built-in intervalometer facilitate star trail and time-lapse astrophotography.

The HX300’s ISO ceiling at 12,800, combined with small sensor noise, makes night shots grainy and less refined.

Video Capabilities: A Big Difference

The Sony A7R III supports 4K UHD video up to 30fps, along with full HD at 60fps. It records using high quality XAVC S codec, with full pixel readout and no pixel binning for sharp, detailed footage. It includes microphone and headphone jacks for monitoring, essential for serious videographers, plus in-body stabilization helps smooth handheld shooting.

Meanwhile, the HX300 maxes out at 1080p Full HD video at 60fps, with no 4K, and no mic or headphone ports. Its video quality is serviceable for casual videos but won’t satisfy those aiming for cinematic quality or professional sound.

Battery Life and Storage

The A7R III punches well above average in battery life for a mirrorless at around 650 shots per charge (using the robust NP-FZ100 battery). It supports dual SD card slots with one slot UHS-II compatible - ideal for professionals needing backup and fast write speeds during bursts.

The HX300’s battery capacity and endurance are less documented, but practically it’s more limited. It uses a proprietary battery, has just a single card slot, and only standard SD support - sufficient for casual shooting but subpar for heavy use.

Connectivity: Modern Conveniences

The A7R III stands out with built-in Wi-Fi, Bluetooth, and NFC connectivity, allowing seamless image transfer and remote control from apps. Its USB 3.1 Gen 1 port supports tethered shooting and fast data transfers.

The HX300 lacks wireless connectivity entirely, relying only on USB 2.0 and HDMI ports - a notable disadvantage for today’s mobile workflows.

Price and Value: What’s Your Budget Buy?

At the time of release, the Sony A7R III’s body commands roughly $2800 USD - an investment aimed squarely at enthusiasts and professionals who demand uncompromising image and build quality. The price matches its performance in a competitive mirrorless market crowded with Nikon Z7 series and Canon R5 rivals.

The HX300, priced around $339 USD new, is an absolute bargain if you want a mega-zoom all-in-one without extra lenses or accessories. It’s a gateway camera for those who care more about reach and straightforward shooting than pixel peeping or editing RAW files.

Final Scores and Summary

After extensive side-by-side testing - shooting portraits, chasing wildlife, roaming city streets, and night skies - the verdict is clear.

The Sony A7R III dominates with superior image quality, versatile lens options, cutting-edge autofocus, and professional features that justify its higher price. It deserves accolades for pushing full-frame mirrorless to its limits (and occasionally beyond).

The HX300 feels like a jack-of-all-trades - great for casual shooters who prize zoom range and minimal fuss, but constrained by its small sensor and simplified technology.

Which Camera Suits Your Photography Style?

Parting Thoughts: Know Your Needs, Choose Wisely

If you’re chasing exceptional image quality, demanding autofocus, versatile lenses, and pro-level video, the Sony A7R III is a camera that will reward your investment for years. It’s a tool built to make your creativity flourish across disciplines - from studio to wild expeditions.

If budget constraints or portability dominate, and you mostly shoot casual photos or videos with an insanely flexible zoom but don’t want to fuss with lenses, then the Sony HX300 remains a compelling choice. Just temper expectations about low-light and image noise.

Both cameras carry Sony’s commitment to innovation, but with vastly different targets - one for passionate creators, the other for flexible everyday shooting.

Sony A7R III front Sony A7R III screen back Sony HX300 front Sony HX300 screen back

In twenty-plus years of camera testing, these Sony models remind me how crucial it is to match gear to your photographic ambitions - not just chase pixel counts or zoom ranges. Choose your camera as you would a good travel companion: reliable, fun, and suited to the journey you want to take.

Happy shooting!