Pentax K-3 II vs Sony A99: An Expert Comparison for Your Next Camera Purchase

Choosing between the Pentax K-3 II and the Sony A99 is a decision that many photography enthusiasts and professionals face when seeking a robust advanced DSLR to elevate their work. Having spent over 15 years testing cameras across genres, we bring you a thorough, hands-on comparison of these two mid-size SLRs. You’ll gain practical insights about how each camera fares in different photography disciplines, their technical strengths, and their real-world performance - with clear guidance on which model best aligns with your creative ambitions and budget.

Getting to Know the Contenders: Pentax K-3 II and Sony A99

Before diving deeper, let’s highlight what these cameras bring to the table based on their core specs:

Both cameras are sizeable DSLRs with robust weather sealing, aimed at advanced amateurs and pros seeking a versatile tool. However, their sensor sizes, autofocus arrays, and features highlight differing photographic philosophies and user priorities, which we’ll unpack in-depth.

Sensor and Image Quality: APS-C Detail vs Full-Frame Depth

The sensor is the heart of any camera, making its characteristics crucial.

Pentax K-3 II

• APS-C sensor measuring 23.5 x 15.6 mm (366.60 mm² area)
• 24MP resolution with no anti-aliasing filter for sharper detail
• PRIME III image processor optimizes noise performance
• Wide ISO range of 100-51200 providing flexibility in varying light
• Outstanding dynamic range at 13.6 EV (DxOMark score)

Sony A99

• Larger full-frame sensor at 35.8 x 23.8 mm (852.04 mm² area)
• Also 24MP resolution but with anti-aliasing filter for moire control
• BIONZ processing engine fine-tunes image output
• ISO 100-25600 native range optimized for low light
• Higher dynamic range at 14.0 EV and superior color depth

Real-World Takeaway: The Sony's full-frame sensor delivers superior low-light performance and a wider tonal range, ideal for landscape and portrait artists craving rich color gradations and cleaner shadows. The Pentax’s APS-C sensor, while smaller, excels in delivering sharpness and detail without the AA filter, suitable for wildlife and macro where cropping is common.

Autofocus Systems: Precision, Speed, and Tracking

Speed and accuracy of autofocus directly affect your ability to capture peak moments.

Pentax K-3 II Autofocus Highlights

• 27 autofocus points, 25 cross-type for accurate detection
• Dual-phase and contrast detection AF in live view and viewfinder modes
• Eye detection AF improves portrait focus precision
• 8.3 fps continuous shooting paired with AF tracking

Sony A99 Autofocus Highlights

• 19 points with 11 cross-type sensors; slightly fewer points
• Dedicated phase detection AF sensor supported by Translucent Mirror technology
• Superior AF tracking speeds with up to 10 fps burst
• Eye detection and face priority AF included
• Live view uses phase detection AF, optimized for fast acquisition

What We Observed in Testing: The Sony’s SLT (Single-Lens Translucent) technology enables nearly uninterrupted autofocus performance even during bursts. It offers an edge in sports, wildlife, and action photography where rapid tracking is critical. The Pentax, though with more AF points, operates a more traditional DSLR AF system that excels in stills and portraiture but is slightly less adept at ultra-fast tracking.

Ergonomics and Handling: Designed for the Field

Comfort and control layout can make or break your shooting experience.

Pentax K-3 II

• Compact, robust magnesium alloy body weighing 800g
• Well-placed dedicated buttons for quick access without menu diving
• 3.2” fixed LCD screen decent for framing and playback
• Optical pentaprism viewfinder with 0.64x magnification providing a natural viewing experience
• Weather sealed to high standard for rugged conditions
• Battery life rated at 720 shots per charge - excellent for extended shoots

Sony A99

• Slightly larger and heavier at 812g but still manageable
• Fully articulating 3” LCD makes it more versatile for video and low/high-angle shooting
• Electronic viewfinder (EVF) with 2.36 million dots allowing you to preview exposure in real-time
• Weather sealing present but the SLT design may accumulate dust differently
• Battery life lower at 500 shots but compensated by fast charging options

Ergonomic Notes: The Pentax’s classic DSLR feel with an optical viewfinder suits photographers who prefer a direct optical experience without lag, making it ideal for outdoor and daylight use. The Sony’s EVF excels in low light and image simulation, especially advantageous when manual exposure tweaking is frequent. The articulated screen on Sony further enhances creativity in difficult angles.

Lens Ecosystem: Glass Options for Creative Freedom

Choosing a camera is almost equally about available lenses.

• Pentax K-3 II uses the Pentax KAF2 mount with access to 151 available lenses including excellent primes and macro options known for rugged weather sealing.

• Sony A99 uses the Sony/Minolta Alpha mount, compatible with 143 lenses and adapters enabling use of full-frame A-mount lenses plus third-party options, though the SLT design may influence lens compatibility slightly.

Insights: Pentax’s extensive rugged lens selection supports wildlife and landscape shooters who need dependable optics outdoors. Sony’s lens ecosystem is broader due to third-party support but lenses tend to be pricier. Also, Sony’s full-frame sensor demands lenses with full-frame coverage to avoid vignetting.

Specialty Photography Performance: How They Compare Across Genres

Let's break down the cameras' performance in major photography disciplines.

Portrait Photography

• Pentax K-3 II shines with its detailed 24MP APS-C sensor lacking the AA filter, capturing tack-sharp images with well-rendered skin tones and creamy bokeh from compatible fast lenses. Eye detection AF helps nail portrait focus.

• Sony A99 delivers richer tonal gradation and controlled noise in shadows thanks to the full-frame sensor. The EVF allows you to preview depth of field and exposure in real time, a boon when crafting portraits.

Recommendation: Choose Sony if smooth tonal transitions and a classic full-frame look are your priority. Pick Pentax for punchy detail and bokeh with more affordable lenses.

Landscape Photography

• Sony A99’s full-frame sensor gives outstanding dynamic range ~14.0 EV, capturing expansive scenes with subtle gradations. Weather sealing and high-resolution EVF aid composition in harsh environments.

• Pentax K-3 II offers 13.6 EV DR with an APS-C sensor; smaller but still impressive. Its renowned Pixel Shift Resolution mode can create ultra-high-res images by combining multiple shots, enhancing detail in static landscapes.

Recommendation: For ultimate image quality in landscapes, Sony’s full-frame edge pays off. For enthusiasts who shoot static scenes and want maximum detail, Pentax K-3 II’s Pixel Shift is unique and effective.

Wildlife Photography

• Pentax K-3 II benefits from 1.5x crop factor extending reach, faster 8.3 fps burst, and weather-sealed rig built for rugged use. Its extensive telephoto lens lineup excels for wildlife.

• Sony A99’s 10 fps continuous shooting and SLT-phase detection AF are superb for fast-moving subjects. However, without sensor crop, you rely more on long lenses to get super-tight framing.

Recommendation: Pentax is better if you want the extra reach that crop sensors provide with affordable lenses. Sony is suited for fast-action capture but with heavier investment in long telephotos.

Sports Photography

• Sony A99 leads with its 10 fps burst and fast AF system capable of reliable subject tracking during fast-paced action.

• Pentax K-3 II is no slouch at 8.3 fps and accurate AF points, but slightly trails in buffer speed and AF tracking efficiency.

Recommendation: Experienced sports shooters who need fast burst and tracking should gravitate to Sony, whereas Pentax fits casual but serious sports shooters on a budget.

Street Photography

• Pentax K-3 II offers a quieter operation, relatively compact size, and excellent weather sealing for unpredictable urban environments.

• Sony A99’s electronic viewfinder and articulating screen aid compositions from challenging angles typical in street work, but its size and the mirrorless-like design may draw more attention.

Recommendation: Pentax is more discreet and rugged for street use; Sony’s EVF helps see around corners and shoot incognito when you get accustomed.

Macro Photography

• Pentax K-3 II’s sharp sensor without AA filter combined with in-body image stabilization enhances macro shooting precision.

• Sony A99 also offers stabilization but the sensor's size and lens choices may limit some macro options.

Recommendation: Pentax’s sharpness and stabilization synergy puts it ahead for macro enthusiasts.

Night and Astrophotography

• Sony A99 excels due to full-frame sensor’s strong high ISO performance (DxOMark low-light ISO: 1555) and minimal noise.

• Pentax K-3 II can push ISO higher (up to 51200) but with more noise; its pixel shift and sensor-based stabilization aid long exposures.

Recommendation: Sony is preferable for clean night skies; Pentax offers value by extending shooting options with sensor-shift tech.

Video Capabilities

• Both cameras offer full HD recording (1920x1080) at multiple frame rates.

• Sony A99’s fully articulating screen and EVF preview edge it for video monitoring.

• Both have microphone and headphone ports for audio control, but neither supports 4K.

Recommendation: Sony suits casual video creators wanting more framing versatility; Pentax covers basics well for hybrid shooters.

Travel Photography

• Pentax’s smaller size, weather sealing, and longer battery life (720 shots) suit extended outdoor travel.

• Sony’s articulated screen and superior low-light sensor quality help in diverse visual conditions but at nearly twice the price.

Recommendation: Pentax K-3 II is best for budget-conscious travelers needing ruggedness; Sony suits those prioritizing best image quality and video flexibility.

Professional Use and Workflow

• Both cameras support full RAW files for maximum post-production control.

• Pentax’s USB 3.0 interface surpasses Sony’s USB 2.0 speed for tethered sessions.

• Sony’s electronic viewfinder aids critical exposure and color decisions straight from capture.

Recommendation: Workflow preferences such as interface speed and EVF benefits will influence pros differently; Pentax has slight edge in data throughput, Sony in real-time previews.

Build Quality and Environmental Resilience

Both cameras sport magnesium alloy bodies with weather sealing against dust and moisture but lack full waterproof proofing.

For outdoor shooters facing rain, dust, or cold conditions, both withstand typical stresses well, but the Pentax’s reputation for rock-solid build quality wins slightly for rugged wildlife and adventure photography.

User Interface and Controls

• Pentax features straightforward physical controls and a fixed LCD. It lacks touchscreen but has customizable buttons and intuitive menus ideal for fast operation.

• Sony sports a fully articulated TFT LCD and an EVF with 2.36 million dots, no touchscreen but sufficient physical buttons. The EVF aids in previewing exposure and white balance changes instantly.

You’ll find the Pentax more traditional and tactile, while the Sony blends DSLR feel with mirrorless-inspired previews. Both keyboards have pros and cons depending on workflow style.

Connectivity, Storage, and Power

• Pentax K-3 II

  • Dual SD card slots for extended storage and backup
  • USB 3.0 for faster file transfer
  • Optional Wi-Fi module (not built-in)
  • Built-in GPS for geotagging images
  • Larger battery life for extended shoots (720 shots CIPA)

• Sony A99

  • Dual card slots supporting Memory Stick Pro Duo and SD cards
  • USB 2.0 connection - slower data transfer
  • No wireless connectivity natively
  • Built-in GPS
  • Shorter battery life (approx. 500 shots CIPA)

For photographers needing robust on-location connectivity and backup, Pentax holds clear advantages.

Price-to-Performance: Budget Meets Capability

While the Sony A99 launched as a flagship model costing nearly $2,000, the Pentax K-3 II remains a high-value camera at under $1,000.

Sample Images: See for Yourself

Pentax K 3 II front Sony A99 front Sony A99 screen back

The gallery above showcases portraits, landscapes, and wildlife shots from both cameras. Notice the Sony’s smooth tonal transitions and quieter backgrounds versus the Pentax’s punchier detail and sharper edges.

Overall Performance Ratings

Sony A99 scores higher primarily due to its sensor size, autofocus speed, and video features, but Pentax K-3 II is no slouch and excels in battery life, ruggedness, and pixel shift resolution innovation.

Genre-Specific Performance Breakdown

• Portrait, landscape, low light, and sports photography lean towards Sony.
• Macro, travel, and budget-friendly detailed capture lean towards Pentax.

Final Thoughts and Recommendations

Who Should Choose the Pentax K-3 II?

• Photography enthusiasts and professionals on a moderate budget.
• Wildlife, macro, and landscape photographers desiring rugged, weather-sealed gear.
• Photographers valuing long battery life and sharp APS-C detail.
• Creators seeking innovative pixel shift feature for ultra-high-res stills.
• Travelers needing compact, reliable gear with GPS and dual SD slots.

Who Should Choose the Sony A99?

• Professionals prioritizing full-frame image quality and rich tonal range.
• Action and sports photographers needing fastest AF and highest burst rates.
• Photographers and videographers requiring an articulating screen and EVF previews.
• Creators demanding streamlined tethering workflow and fine exposure control.
• Users with larger budgets aiming for a more versatile but heavier DSLR.

Getting Started and Exploring Further

Whichever camera you gravitate toward, we recommend hands-on trials to experience ergonomics and handling firsthand. Check out lenses matching your style and consider accessories like battery grips, external flashes, and wireless modules to extend functionality.

Your choice will reflect your photographic priorities - from the rugged APS-C powerhouse of the Pentax K-3 II to the full-frame sophistication and speed of the Sony A99. Both bring decades of innovation and reliability to your creative journey.

Thank you for trusting our experience. Dive deep, experiment boldly, and let your next camera inspire your vision.