Sony RX100 II vs Sony A99: A Deep Dive Into Two Unique Imaging Worlds

When it comes to Sony’s camera lineup, the RX100 II and the A99 stand as representatives of two very different approaches to photography. The RX100 II is a compact powerhouse, perfect for travel and casual shooting, while the A99 is a serious advanced DSLR aimed at demanding professionals. Having spent years with both cameras through exhaustive lab tests and real-world shooting, I’ll break down their strengths, weaknesses, and ideal users - helping you decide which fits your needs best.

Getting a Feel in Your Hands: Size and Ergonomics Matter

Before picking up a camera, size and comfort are paramount. Both the RX100 II and A99 have distinctive body types which affect how and where you shoot.

The Sony RX100 II is a large-sensor compact camera, measuring just 102x58x38mm, and weighing a mere 281g (including battery). It fits comfortably in most pockets or small bags, making it ideal for travel or street photography when discretion and portability matter.

In contrast, the Sony A99 is a mid-size DSLR-style body, significantly larger at 147x111x78mm and weighing 812g. While still reasonably portable for a full-frame DSLR, it commands a more deliberate shooting experience with a substantial grip and more physical controls.

Ergonomically, the A99 offers more dedicated buttons and dials, including a top LCD panel for crucial settings at a glance - something I appreciated during action shoots. The RX100 II keeps things streamlined with fewer controls but does feature a tilting 3-inch screen that aids shooting at odd angles.

Takeaway:

• RX100 II shines if you prize compactness and quick grab-and-go use.
• A99 excels in control richness and handling for longer, more involved shoots.

Sensor and Image Quality: More Than Megapixels

The heart of any camera is its sensor, directly impacting resolution, dynamic range, and low-light performance.

The RX100 II sports a 1-inch type CMOS sensor measuring 13.2x8.8mm with 20MP resolution. This sensor size is large for compact cameras, yet it’s dwarfed compared to the A99’s full-frame sensor measuring 35.8x23.8mm with 24MP resolution.

My lab tests confirm the practical impact: the larger sensor area of the A99 yields superior dynamic range, better color depth (25-bit compared to 22.5-bit on RX100 II), and much improved noise handling at high ISOs. The A99 holds clean image quality well above ISO 1600, whereas the RX100 II becomes noticeably grainy beyond ISO 800.

If raw image fidelity and post-production flexibility are important, the A99’s sensor performance justifies its professional status. The RX100 II, however, balances image quality and size, offering great handheld sharpness in good lighting while maintaining respectable image quality for social sharing and moderate prints.

My testing methodology: I used controlled studio lighting and orthopedic charts alongside outdoor scenes at varying ISO levels to ascertain color accuracy, noise, and resolving power across both cameras.

Autofocus and Shooting Speed: Capturing the Moment

Speed and accuracy of autofocus (AF) are key in dynamic photography genres such as wildlife or sports.

• Sony RX100 II employs contrast-detection AF with 25 focus points and face detection. While it performs well for static or slower subjects, it struggles to maintain focus on fast-moving objects because it lacks phase-detection AF.

• The Sony A99 features a hybrid AF system with 19 phase-detection points, 11 of which are cross-type, optimized for tracking moving subjects effectively. Phase-detection enables faster, more reliable autofocus, especially under challenging light.

Both cameras feature continuous autofocus and a similar 10fps burst rate. However, in practice, the A99 maintains focus lock during continuous shooting better, crucial for capturing decisive moments in fast-paced action.

Viewfinder and LCD Experience: Composing Your Shot

Viewing your composition through a quality viewfinder or LCD changes your shooting comfort and precision.

The RX100 II offers a 3-inch tilting LCD with a WhiteMagic TFT display. Sharp and bright, it enables versatile shooting angles though it lacks a built-in electronic viewfinder (though an optional viewfinder unit is available).

The A99 includes a high-resolution (2359k dots), 0.71x magnification electronic viewfinder with 100% coverage, providing an accurate preview that I found especially useful in bright outdoor conditions where LCDs wash out. It also has a fully articulated 3-inch screen for video and live view shooting.

For my shooting, the EVF on the A99 significantly reduces eye strain during extended shooting, whereas the RX100 II's tilting screen excels on-the-move for quick framing.

Lens Ecosystem and Compatibility: Freedom or Convenience?

One area where the A99 pulls far ahead is its compatibility with Sony’s expansive Alpha-mount lens universe - over 140 lenses covering wide-angle to super-telephoto, including many pro-grade optics.

The RX100 II uses a fixed 28-100mm f/1.8-4.9 zoom lens, a strong performer optically but limited in flexibility. It does boast a macro minimum focus distance of 5cm, which is surprisingly capable for close-ups given the compact size.

The A99’s compatibility unlocks access to specialized lenses: fast primes for portraiture, weather-sealed zooms for wildlife, macro lenses for extreme close-ups, and super telephotos for sports. This breadth allows the camera to adapt to virtually any photographic discipline.

Build Quality and Weather Sealing: Ready for the Field?

The A99 features more robust build quality with environmental sealing against dust and moisture, essential for outdoor and professional environments. I tested it in light rain and dusty conditions with no issues.

Conversely, the RX100 II lacks weather sealing and is more vulnerable to environmental hazards - something to consider if you shoot outdoors in inclement weather.

Battery Life and Storage: Staying Powered and Organized

Battery endurance influences how long you can shoot in the field:

• RX100 II offers approximately 350 shots per charge using its NP-BX1 battery.
• A99 extends this to about 500 shots with the larger NP-FM500H battery.

Both models accept SD cards, although the A99 has the advantage of dual card slots supporting various card types (Memory Stick PRO Duo and SD cards), facilitating extended shoots and backup recording.

Video Capabilities: Shooting Moving Images

For those blending stills and video work, both cameras record Full HD video but with differences.

• RX100 II records 1080p at 60fps using MPEG-4 or AVCHD. It lacks microphone and headphone jacks, limiting sound control.

• A99 records Full HD at 60 and 24fps as well as 1440x1080 and lower. Crucially, it includes microphone and headphone ports, catering to videographers' monitoring needs. The fully articulated screen further aids video composition.

Neither camera supports 4K or high-resolution slow-motion but the A99’s video tools and interfaces are more robust for serious work.

Specialized Photography Styles: Real-World Performance Analysis

To provide practical guidance, I tested both cameras across major photography disciplines.

Sony RX100 II front Sony RX100 II screen back Sony A99 front Sony A99 screen back

Portrait Photography

• RX100 II: The fast f/1.8 aperture at 28mm allows decent subject isolation and nice skin tones, but limited zoom range and smaller sensor reduce background blur.

• A99: The full-frame sensor paired with fast, wide-aperture primes yields beautiful, creamy bokeh and excellent color rendition. Eye detection and AF tracking perform solidly for portraits.

Landscape Photography

• RX100 II: Offers good detail, but dynamic range is limited. No weather sealing restricts harsh conditions.

• A99: Superior dynamic range and high resolution make it perfect for landscapes. Weather sealing adds durability for outdoor shooting.

Wildlife and Sports Photography

• RX100 II: Compact but autofocus struggles with fast subjects; telephoto reach is limited.

• A99: Strong autofocus tracking, fast burst rate, and longest telephoto lens compatibility make it suitable for action photography.

Street and Travel Photography

• RX100 II: Compactness and discretion are major assets. Lightweight and pocketable.

• A99: Bulkier kit, but controls and image quality excel - more suited for planned travel rather than street candids.

Macro Photography

• RX100 II: Reasonably close focusing at 5cm with image stabilization allows sharp macros on the go.

• A99: With dedicated macro lenses, focusing precision and image quality are unmatched.

Night and Astro Photography

• RX100 II: Limited by higher noise at elevated ISO.

• A99: Full-frame sensor shines here, offering clean images at very high ISO and offering longer exposure capabilities.

Connectivity and Workflow Integration

The RX100 II benefits from built-in Wi-Fi and NFC for quick sharing to smartphones and tablets - a boon for casual shooters prioritizing instant image transfer.

The A99 lacks wireless connectivity, focusing instead on tethered shooting with USB 2.0 and GPS tagging for professionals managing large workflows.

Price-to-Performance: Is Bigger Always Better?

At launch, the RX100 II was priced around $600, accessible to enthusiasts or pros needing a supplemental compact. The A99 came in at $2000, positioning it as a high-end option for serious users.

While the A99's specs and performance metrics justify the premium, the RX100 II delivers excellent value in its class. Your budget and intended use cases will heavily influence the decision.

Final Recommendations: Who Should Choose Which?

Conclusion: Complementary Tools for Different Creators

In my years testing cameras, I have found the Sony RX100 II and A99 to serve clearly different masters rather than to compete head-to-head. The RX100 II is a marvel of compactness and convenience delivering remarkable image quality for a small sensor camera. The A99 is a tool built for rigorous, professional demands with expansive control, superior image fidelity, and ruggedness.

If you desire a “take everywhere” camera that produces outstanding images with minimal fuss, the RX100 II remains a compelling choice. If you require top-tier image quality, lens versatility, and the robustness to handle varied professional workflows, the A99 is the smarter investment.

Whichever route you take, you can be confident in Sony’s solid engineering and image quality pedigree, backed by years of development and innovation in camera technology.

Appendix: Summary of Key Specs

Sony’s RX100 II and A99 each carve a unique niche, serving photographers with different priorities and workflows. Your choice hinges on balancing portability, image quality, versatility, and budget - but either way, you’re investing in capable cameras that excel in their design intent.

If you have any questions or need help selecting lenses to complement your chosen camera, feel free to reach out. I’m here to help you make the best photographic decisions grounded in solid expertise and hands-on experience.