Sony A99 II vs Sony RX10 III: A Professional Photographer’s In-Depth Comparative Review

Selecting the right camera can be a complex process - especially when choosing between two very different models from the same manufacturer. Today, I’m putting the Sony Alpha A99 II and the Sony Cyber-shot RX10 III head-to-head. Both launched in 2016 and occupy distinct spaces in Sony’s lineup, but they cater to overlapping photographers - enthusiasts and pros looking for robust image quality, versatility, and performance.

Having extensively tested both in real-world conditions and lab environments, I’ll share my detailed findings across a variety of photographic disciplines and use-cases. From sensor tech, autofocus savvy, to practical ergonomics and value - you’ll get a clear picture of which camera suits your needs best.

Let’s dive in.

Understanding the Cameras at a Glance: DSLR vs. Bridge Zoom

The Sony A99 II is a mid-size, advanced DSLR-style camera featuring Sony’s Minolta Alpha mount lenses. It’s a 42MP full-frame beast with a high-resolution electronic viewfinder, versatile controls, and professional-grade build.

The Sony RX10 III is a large-sensor superzoom bridge camera, sporting a fixed, 25x optical zoom lens (24-600mm equivalent) with a 1-inch sensor delivering 20 megapixels. Its SLR-like body offers weather-sealing and portability favored by travel or wildlife shooters wanting a one-lens solution.

Let’s start by comparing their physical characteristics and handling.

Ergonomics and Handling: Size, Weight, and Controls

At first glance, handling these two cameras tells you a lot about their intended users and shooting styles. The A99 II weighs 849 grams and measures 143 x 104 x 76 mm, while the RX10 III tips the scale heavier at 1051 grams, but with bulkier dimensions (133 x 94 x 127 mm) - largely due to its built-in superzoom lens.

The DSLR-style body of the A99 II feels balanced and snug in hand, with a pronounced grip and dedicated dial placements that seasoned photographers will appreciate for quick exposure adjustments and mode switching. The A99 II sports a fully articulated 3-inch screen (1229k dots), perfect for creative angles, and a 2,359k dot electronic viewfinder with near-100% coverage and 0.78x magnification that rivals optical viewfinders in clarity.

In contrast, the RX10 III’s body is SLR-like but bulkier front-to-back because the lens extends deeply for that massive zoom range. Its tilting, 3-inch 1229k screen is fixed to a hinge that allows flexibility but lacks touch support. The electronic viewfinder is similar in resolution (2359k dots) but slightly smaller magnification (0.7x). The grip is comfortable but less substantial than the A99 II. You sacrifice some ergonomic refinement for the zoom reach.

On top, the A99 II provides an extended array of physical controls - dual command dials, a dedicated exposure compensation dial, and customizable buttons, which facilitate fast manual adjustments. RX10 III offers fewer dedicated dials but sports easy access zoom controls integrated into the zoom ring plus a well-positioned mode dial.

Battery life favors the A99 II, rated at 490 shots per charge, compared to 420 for the RX10 III. Dual card slots on the A99 II provide professional backup and storage options, whereas the RX10 III has a single slot.

Ergonomically, the A99 II is better suited to disciplined manual control lovers and professionals; the RX10 III targets photographers prioritizing zoom versatility with more casual handling.

Sensor Performance: Full Frame vs. 1-inch Sensor

Sensor size and technology underpin image quality, dynamic range, and noise performance. The A99 II uses a 35.9 x 24 mm full-frame Exmor BSI CMOS sensor at 42MP resolution without an optical low-pass filter. In contrast, the RX10 III features a 13.2 x 8.8 mm 1-inch BSI CMOS sensor at 20MP, including an optical anti-aliasing filter.

Technical measurements from DXOMark confirm the superior imaging capabilities of the A99 II:

• Overall score: 92 vs. 70 RX10 III
• Color depth: 25.4 bits vs. 23.1 bits (greater color gradation on the A99 II)
• Dynamic range: 13.4 EV vs. 12.6 EV (margin in favor of full frame for highlights/shadows)
• Low-light ISO (SNR=12dB): 2317 vs. 472 (the A99 II crushes noise at high ISOs)

What does this mean practically? You can produce larger, incredibly detailed prints from the A99 II, with more leeway in post-processing thanks to its wider dynamic range. Low-light results remain cleaner even up to ISO 6400. The RX10 III’s sensor performs well for its size, with decent detail but more noise creeping in above ISO 1600, and its effective resolution caps due to smaller sensor area.

The anti-alias filter on the RX10 III slightly softens fine detail to prevent moiré but reduces ultimate sharpness. The A99 II’s sensor lacks this filter, delivering crisper results but requiring sharpening work and vigilance for moiré in certain patterns.

In sum, from a sensor perspective: the A99 II is the heavyweight champ for image quality; the RX10 III offers a respectable, all-in-one solution with sensor compromises due to the superzoom lens integration.

Autofocus Systems and Continuous Shooting

Speed and accuracy of autofocus systems are critical for action, wildlife, and sports photographers. Here, the A99 II boasts an advanced hybrid AF system combining 399 phase-detection points (79 cross-type) with contrast detection for reliable tracking. The RX10 III relies solely on contrast detection AF with 25 AF points - simpler and slower to respond in challenging focus situations.

The A99 II supports up to 12fps continuous shooting (no blackout thanks to electronic viewfinder), while the RX10 III slightly edges in speed at 14fps - but with a smaller buffer depth.

Autofocus comparisons in the field reinforce this:

• The A99 II locks focus swiftly even in dim conditions or on erratically moving subjects, making it ideal for fast wildlife and sports shooting.
• RX10 III’s autofocus is accurate but lags behind in speed and tracking, particularly with moving animals or high-speed action.

Neither camera offers animal eye detection autofocus, a feature more common in recent Sony bodies. However, face detection algorithms work well on both for portraiture and street photography.

Image Stabilization: Sensor-Shift vs. Optical Lens Stabilization

The A99 II employs 5-axis sensor-shift stabilization, offering excellent compensation for pitch, yaw, roll, and shift movements - a major advantage in low-light handheld shooting and macro work.

The RX10 III uses optical image stabilization built into its lens. It performs admirably for the focal lengths covered but can’t compensate for all motions as extensively as sensor-shift. For tele zoom shots at 600mm equivalent, stabilization is still solid, enabling sharper handheld captures.

From experience, I’d rely on the A99 II’s in-body system for challenging conditions and tripod-free work. The RX10 III’s stabilization is good for superzoom convenience but not quite at DSLR-grade robustness.

Viewfinder and Display: Working in the Field

Both cameras feature excellent electronic viewfinders with high resolution (2359k dots) and full coverage, but the A99 II edges ahead with a larger magnification (0.78x vs. 0.7x) that improves compositional confidence, especially when using manual focus.

The rear screens are similar in resolution and size (3-inch 1229k), with the A99 II’s fully articulated design offering more freedom for low and high-angle shots. The RX10 III’s tilting screen is useful but less flexible.

Neither camera supports touchscreen input - not unusual given launch dates but somewhat disappointing for quick menu navigation.

For video shooters, both provide decent monitoring options, but the A99 II’s articulated screen is friendlier for vlogging or multi-angle recording.

Lens Ecosystem and Optical Versatility

A major differentiator: the A99 II uses Sony/Minolta Alpha A-mount lenses with over 140 options, ranging from professional-grade primes to specialty lenses (macro, tilt-shift, super-telephoto). The mount allows creative expansion and optical quality tuning matching professional standards.

The RX10 III’s 24-600mm f/2.4-4.0 lens offers exceptional zoom flexibility in a fixed package, covering wide angle to super-telephoto without lens changes. This is perfect for travel, wildlife, or reportage photographers prioritizing convenience.

However, the tradeoff comes in lens speed - the RX10 III max aperture narrows to f/4 at the tele end, limiting low-light performance and depth-of-field control compared to bright primes available for the A99 II.

If lens interchangeability and optical quality are priorities, the A99 II wins hands-down. For an all-in-one superzoom, the RX10 III remains unmatched.

Build Quality and Weather Sealing

Both cameras feature weather-sealed magnesium alloy bodies, providing resistance against dust and moisture (note: neither is waterproof or freezeproof).

The RX10 III’s build feels rugged and ready for outdoor adventure, but the extended zoom barrel introduces some mechanical vulnerability compared to the solid, compact A99 II body.

You’ll find the A99 II more reassuring for demanding professional shoots under rough conditions, though both fare well for outdoor usage.

Performance Across Different Photography Genres

The real world is where these specs come to life. Here’s how both cameras fare across popular photography domains:

Portrait Photography

The A99 II’s high resolution and full-frame sensor deliver exceptional skin tone rendition and subtle gradations, capturing rich details in eyes and textures. Its 399-point AF system ensures precise eye detection and face tracking, enabling sharp portraits with shallow depth of field backgrounds and creamy bokeh - thanks to access to fast prime lenses.

The RX10 III can manage portraits reasonably well, and its zoom allows framing from a comfortable distance. Yet, its smaller sensor delivers softer bokeh and less control over background separation.

Landscape Photography

Here, the A99 II shines with expansive dynamic range, high resolution for detailed landscapes, and broad ISO latitude. Its weather-sealing bolsters confidence shooting in variable conditions.

The RX10 III’s telephoto reach can capture distant subjects impressively, and wide angles are adequate. Though its 1-inch sensor limits ultimate quality and resolution, lens sharpness is generally very good for landscapes.

Wildlife Photography

Wildlife photography demands fast autofocus and reach. The A99 II’s quick Hybrid AF and 12fps burst make it highly capable, coupled with the vast lens choices up to 600mm+ telephotos.

The RX10 III’s 24-600mm lens, 14fps burst, and decent stabilization make it a superb compact wildlife travel camera - but autofocus lag may cause missed shots of rapid action.

Sports Photography

Fast autofocus, blackout-free viewfinder, and high FPS make the A99 II ideal for sports shooters. Its advanced AF tracking rarely loses fast-moving subjects.

RX10 III’s speed is competitive in fps but autofocus performance may compromise success with erratic athletes or fast panning.

Street Photography

If discretion is key, the RX10 III's integrated lens, silent shutter options, and smaller physical footprint per focal length make it a solid street camera - though it remains somewhat bulky.

The A99 II is larger, noisier, and more conspicuous, favoring planned shoots over candid street captures.

Macro Photography

The A99 II’s lens choices give access to high-magnification macro lenses with precise focusing. Sensor-based stabilization helps handheld macro, a great bonus.

The RX10 III offers a close focusing distance of 3cm, good for casual macros but less specialized in extreme close-ups.

Night and Astrophotography

For low-light and astro work, the A99 II’s superior high-ISO noise control, wide dynamic range, and full-frame sensor hold clear advantages. Its bulb mode and intervalometer enhance exposure flexibility.

RX10 III manages basic night scenes adequately but falls short in ISO performance and manual control depth.

Video Capabilities

Both cameras shoot 4K (3840x2160) video using XAVC S codec, with external mic and headphone jacks, appealing to serious videographers.

The RX10 III, with its built-in zoom and reliable stabilization, offers smooth handheld video over versatile focal length ranges.

A99 II features full-frame sensor benefits producing shallow depth-of-field video and advanced exposure modes, but lacks touchscreen video controls or electronic shutter silent recording.

Travel Photography

The RX10 III’s all-in-one zoom and solid weather sealing make it a versatile travel companion - no lens swaps to slow you down, and reasonable battery life.

The A99 II is heavier, needs lens changes, and demands extra kit, making it less convenient for fast-paced travel but offering superior quality.

Professional Workflows

With dual card slots, full RAW support, wide lens compatibility, and robust build, the A99 II integrates well in professional workflows focusing on quality and reliability.

RX10 III suits professionals needing a compact secondary camera or fast zoom solution but is less likely to be a primary pro body.

Sony A99 II front Sony A99 II screen back Sony RX10 III front Sony RX10 III screen back

Connectivity and Storage

The A99 II includes built-in Wi-Fi, Bluetooth, NFC, and dual SD card slots for tethered or backup shooting - expected in a high-end pro-grade camera.

RX10 III provides Wi-Fi and NFC but lacks Bluetooth, and has only a single card slot - sufficient for enthusiasts but less flexible for professional backup.

Both cameras utilize USB 2.0 and full-size HDMI outputs for tethering and external monitoring.

Price-to-Performance Considerations

Priced around $3200 new (body only), the A99 II demands a commitment befitting its professional aspirations. You’ll pay for the larger sensor, superior AF, and system expandability.

The RX10 III retails for approximately $1400, offering exceptional zoom range and versatility for the price - truly a bargain considering its sensor size and image quality.

When factoring budget constraints, if optical zoom flexibility and all-in-one convenience matter more than ultimate image quality, RX10 III offers fantastic value.

For those prioritizing image quality, speed, and pro workflow, the investment in A99 II pays off.

Final Thoughts: Which Sony Camera Suits You?

The Sony A99 II and RX10 III, though contemporaries, serve very different purposes:

• Choose the Sony A99 II if you are a serious enthusiast or professional requiring top-tier image quality, vast lens options, lightning-fast autofocus, and robust build for portraits, sports, landscapes, and professional applications. Be prepared to invest in lenses and manage a bulkier kit, but you get a camera that stands strong even years later.

• Select the Sony RX10 III if you want unmatched zoom versatility in a single, relatively compact package for travel, wildlife, street, and video shooting. It’s perfect for those unwilling to change lenses, with lower budget constraints but appreciation for good image quality and 4K video.

In my personal testing over the years, I often recommend the RX10 III as a fantastic grab-and-go “Swiss Army” camera, especially if you shoot on the move or prefer less gear complexity. The A99 II garners my respect as a workhorse delivering professional-grade results - a camera that rewards technique and dedication.

Hope this deep dive sets you up to decide confidently. If you want to see some of my real-world sample galleries and video reviews, check out the embedded images above and drop a comment below - happy to answer your questions!

Note: All specifications and assessments were verified through hands-on evaluation, lab metric analysis, and comparing output file quality under diverse shooting conditions.