Sony A7 III vs Sony RX1R II: A Deep Dive Into Two Full-Frame Titans

In the ever-evolving landscape of photography, Sony’s full-frame offerings have carved out a special place for themselves, appealing to professionals and enthusiasts alike. But when faced with two very different yet compelling options - the versatile Sony Alpha A7 III and the pocketable, high-resolution Sony RX1R II - the decision can feel daunting. Drawing on my extensive hands-on experience testing thousands of cameras across genres, I’m here to break down how these two stack up in real-world situations, technical performance, and overall value. Together we’ll explore everything from sensor capabilities to ergonomics, so whether you’re chasing wildlife, shooting portraits, or traveling light, you’ll know which camera earns your hard-earned dollars.

First Impressions: Size, Build, and Handling

Stepping from one camera to another in my day-to-day work often reveals nuances invisible on spec sheets. Let’s start by sizing them up.

The Sony A7 III is your classic SLR-style mirrorless system camera - not small, but solidly built with a substantial grip and all-weather sealing. Its 127 x 96 x 74 mm body and 650-gram weight feel reassuringly robust in hand. I found it comfortable to shoot with for extended periods across multiple disciplines.

In contrast, the RX1R II impresses with its remarkably compact footprint: 113 x 65 x 72 mm and only 507 grams. It’s a true large sensor compact, meaning it slips effortlessly into my jacket pocket or small bag - ideal when carrying minimal gear is a priority. The fixed lens design eliminates lens-fright, and its all-metal construction conveys premium build quality despite lacking weather-sealing.

Ergonomically, I found the A7 III excels with customizable buttons, a well-positioned mode dial, and dual card slots - a boon for reliability in professional workflows. The RX1R II’s control layout is simpler, focused, and somewhat minimalist, better suited to candid street shooters who prefer an intuitive point-and-shoot experience without fuss.

If you prize ergonomics and ruggedness, the A7 III clearly takes the lead. But for compactness and a more discrete shooting style, the RX1R II is an absolute gem.

Sensor and Image Quality: A Battle of Resolution and Technology

Sony’s full-frame sensors have powered some of the best cameras of recent years, but here we have two very different approaches - one optimized for versatility, the other for absolute resolution.

The A7 III features a 24MP full-frame back-illuminated CMOS sensor measuring 35.8 x 23.8 mm, offering a good balance of resolution, noise performance, and dynamic range. Its sensor area is 852 mm², paired with the tried-and-true Bionz X processor.

The RX1R II packs a whopping 42MP full-frame BSI-CMOS sensor (35.9 x 24 mm), making it one of the highest resolution 35mm compact cameras ever. Its sensor size is slightly larger at 861 mm², and uniquely, it omits the anti-aliasing filter, enhancing fine detail reproduction - perfect for landscape and portrait shooters who require ultimate sharpness.

Technically, the RX1R II has the edge in sheer resolving power, offering maximum image dimensions of 7952 x 5304 pixels versus 6000 x 4000 on the A7 III. Color depth and dynamic range, as measured in standardized DXO tests, favor the RX1R II slightly (25.8-bit color depth versus 25.0 and 13.9 vs 14.7 stops dynamic range, respectively). The A7 III, however, pulls ahead in low-light ISO (DXO low light ISO of 3730 compared to 3204), indicative of its more modern sensor tech and improved noise management.

From personal testing, the RX1R II’s images display breathtaking detail straight out of the camera - ideal for large prints or pixel-peeping landscape work. The A7 III strikes a superb balance of sharpness, color fidelity, and noise control, making it more versatile when shooting in challenging light conditions.

Display and Viewfinder: Real-Time Feedback

Shooting is as much about the interface as the image quality, so let’s look at screens and viewfinders.

Both cameras boast a 3-inch tilting LCD, but the RX1R II’s screen has a higher resolution at 1229k dots compared to 922k on the A7 III, making it slightly crisper for playback. Yet, the A7 III’s touchscreen capability provides a much more fluid and intuitive user experience - especially when navigating menus or focusing through touch.

For viewfinders, both use electronic displays with equal 2359k-dot resolution and 100% coverage. Physical magnification is 0.78x on the A7 III, a bit larger than the RX1R II’s 0.74x, contributing to a slightly more immersive experience in the latter.

In practical use, the A7 III’s more responsive touchscreen and customizable display overlays help speed up shooting, making it a favorite for fast-paced environments like sports or wildlife. The RX1R II’s higher-res LCD is a boon when reviewing precise detail, suited to slower, contemplative photography.

Autofocus Systems: Speed vs Precision

Let me tell you, autofocus can make or break a shoot. And here the gap between these two is stark.

The Sony A7 III sports a 693-point hybrid autofocus system combining phase and contrast detection, with advanced eye and animal eye detection. In my testing with fast-moving subjects - birds in flight, athletes in low light - the A7 III’s AF tracked with remarkable accuracy and consistency. Continous AF at 10 fps burst made it my go-to for wildlife and sports, where split-second focus can mean the difference between a winning shot and a missed opportunity.

Conversely, the RX1R II uses a more traditional contrast-detection AF with 25 focus points. While accurate in controlled conditions, I found it slower and less reliable tracking moving subjects or in low light. There’s no continuous AF burst mode, and eye detection at the time was less developed.

For portrait work, the A7 III’s eye AF shines, grabbing pin-sharp focus on eyes even with moving subjects. The RX1R II can produce fantastic tack-sharp images but requires more patient manual focusing or locking onto static subjects.

If autofocus speed and reliability are priorities - especially for wildlife or sports - the A7 III wins hands down. But if your style is deliberate and precise, and you prefer manual focus feel, the RX1R II is no slouch.

Lens Ecosystem and Versatility

One unavoidable difference is lens compatibility.

The A7 III’s Sony E-mount opens the door to 121 native lenses - from ultra-wide angles to super-telephotos - and third-party optics ranging from affordable primes to pro-grade glass. This versatility supports a huge range of applications, from architecture to macro, travel to weddings.

The RX1R II comes with a fixed, legendary 35mm f/2 Zeiss Sonnar prime lens, which delivers exceptional optical quality with minimal distortion or chromatic aberration. Its close focusing at 14cm also allows for compelling close-ups. But there’s no option to swap lenses, meaning if you crave zoom or specialty glass, you’re out of luck.

In my workflow, the fixed lens encourages creativity within constraints - perfect for minimalists or street photographers. But for anyone demanding flexibility to adapt on the fly or build a system, the A7 III’s extensive lens choice is decisive.

Handling the Spectrum: Photography Genres Put to Test

How do these cameras perform across popular photography styles? Here’s my hands-on breakdown.

Portraits

The RX1R II’s 42MP sensor combined with its superb 35mm f/2 lens produces jaw-dropping image detail and glorious skin tones - ideal for fine art portraits. Its lack of eye AF means you’ll want to practice focus precision, but when nailing it, the results rival medium format.

The A7 III’s eye and animal eye AF, faster frame rate, and more flexible lens options (85mm, 135mm primes) make it my preference for portraits in dynamic or outdoor settings with moving subjects.

Landscapes

Resolution and dynamic range matter greatly here. The RX1R II shines thanks to higher pixel count and no AA filter, exhibiting extraordinary detail in trees and textures, especially in RAW files. Its 35mm focal length, while less classic for landscapes, can work beautifully when thoughtfully composed.

I preferred the A7 III for adventuring thanks to its weather sealing and longer battery life (610 vs 220 shots per charge), granting more confidence on rugged hikes or inclement weather.

Wildlife and Sports

The A7 III excels with blazing autofocus, 10 fps shooting, and excellent noise control to chase fast action even at dusk. The RX1R II’s slower, contrast-only AF and 5 fps cap limit usability here - best saved for static wildlife or editorial-style animal portraits.

Street Photography

Compactness and unobtrusiveness count enormously. The RX1R II’s pocketable size, quiet shutter, and high image quality make it a stealthy street weapon. Its fast 35mm lens is perfectly suited for spontaneous scenes.

Although larger, the A7 III’s silent shutter mode and tilt screen offer advantages for flexibility and creative angles, but it will always attract more attention than a pocket camera.

Macro Photography

The A7 III again takes the prize with compatible macro lenses and in-body image stabilization, supporting handheld close-up shots with high precision. The RX1R II’s fixed lens allows close focusing only to 14cm, which can deliver compelling detail but is less versatile.

Night and Astrophotography

Here, the A7 III’s superior high ISO performance and advanced exposure modes make longer exposures easier and cleaner. I’ve shot Milky Way scenes where the 24MP balance between noise and resolution performs beautifully.

While the RX1R II’s resolution is tempting, its noisier high ISO and shorter shutter max speed (4000 vs 8000) restrict astrophotography capabilities somewhat.

Video and Audio

The A7 III supports 4K recording up to 30p with full pixel readout, plus high-frame-rate 1080p options for slow motion. It includes microphone and headphone jacks for pro audio monitoring, making it a solid choice for hybrid shooters.

The RX1R II tops out at full HD 1080p with no 4K, and lacks a headphone jack, limiting its utility for serious videography.

Connectivity, Storage, and Battery Life

Wireless features on the A7 III are more extensive with built-in Wi-Fi, Bluetooth, and NFC support, facilitating fast image transfers and remote control.

Storage-wise, dual SD card slots on the A7 III bring peace of mind and extended shooting, while the RX1R II has a single slot only.

Battery life is another key practical difference: the A7 III’s NP-FZ100 cell delivers roughly 610 shots per charge under CIPA standards, while the RX1R II’s NP-BX1 powers approximately 220 shots. This means extended travel or event coverage favors the A7 III’s stamina.

Price and Value: Getting the Best Bang for Your Buck

Currently, the A7 III hovers around $1998 (body only), while the RX1R II sits significantly higher at approximately $3300.

This price difference reflects the RX1R II’s specialized design, fixed high-end lens, and ultra-high resolution sensor packed into a compact body. The A7 III’s more mainstream appeal and broad capabilities make it better value for many users.

If budget permits and the highest image resolution in a pocketable format is your priority, the RX1R II is worth considering. But for multi-disciplinary use and overall bang-for-buck, the A7 III stands out.

Sony A7 III front Sony A7 III screen back Sony RX1R II front Sony RX1R II screen back

Above, the sample gallery exhibits stunning detail from the RX1R II’s high-res sensor (portrait close-ups, landscape textures) alongside the A7 III’s versatile shots in low light and action sequences.

The overall and genre-specific scorecards reflect the strengths I’ve described: the A7 III’s balance and speed, and the RX1R II’s high fidelity and size advantage.

Final Thoughts: Who Should Buy Which?

To summarize from my in-depth field testing and technical evaluation:

Choose the Sony A7 III if you:

• Need a full-frame system camera with excellent autofocus across all subjects
• Shoot action, wildlife, sports, or require low-light versatility
• Value a broad lens ecosystem and weather sealing
• Require 4K video capabilities and pro audio inputs
• Want longer battery life and dual card slots
• Prefer a robust grip and customizable controls

Choose the Sony RX1R II if you:

• Prioritize uncompromising image resolution and optical quality in a compact, pocketable body
• Are mainly focused on landscape, studio, or portrait photography where resolution and fine image detail matter most
• Prefer simplicity of a fixed 35mm f/2 prime without changing lenses
• Shoot primarily stills, with less emphasis on fast autofocus or video
• Appreciate minimalist design and discreet street shooting

In Closing

Both cameras offer outstanding performance for their respective niches. The A7 III is a workhorse, a multi-talented professional mirrorless that thrives in any photographic adventure. The RX1R II is a precision instrument for those who demand exceptional image quality in a minimalistic package and are willing to forgo some features and speed.

I encourage readers to consider their shooting style, subjects, and photographic ambitions carefully. It’s about more than specs; personal comfort and creative freedom always matter most. Should you wish, I am happy to provide insights on lenses or accessories that complement each system best.

Happy shooting!

Disclaimer: I have no commercial affiliation with Sony; all opinions here are derived from direct testing, lab measurements, and practical experience.