Choosing Between the Pentax 645D and Sony A68: A Hands-On Comparative Exploration

In the ever-evolving world of photography gear, selecting the right camera isn’t just about megapixels or brand prestige - it’s about matching technical capabilities with your creative vision and shooting style. Today, I’m bringing you a detailed, experience-driven comparison of two camera systems that sit at almost opposite ends of the photographic spectrum yet often surface in the same discussions: the professional medium format Pentax 645D and the budget-friendly, APS-C Sony A68. Both models present compelling propositions, but also inherent compromises.

Having spent countless hours with these bodies, testing their nuances in the field, and pitting them against genre-specific challenges, I’m here to share insights distilled straight from the trenches. Let’s deep dive into the practical realities and technical complexities that differentiate these cameras - so you can confidently decide which one deserves a place in your bag.

A Tale of Two Cameras: Size, Ergonomics, and Handling

Right out of the gate, their physical presence sets them worlds apart. The Pentax 645D is a large, hefty beast - a true testament to its professional medium format heritage. The Sony A68, meanwhile, leans compact and manageable, feeling more like a contemporary DSLR for enthusiasts and amateurs.

Pentax 645D: Weighing in at nearly 1.5 kg with dimensions of 156 x 117 x 119 mm, the 645D is no pocket camera. Its bulk demands respect and intention - almost ceremonial, if you will. The deep grip and robust build convey a reassuring sense of durability, integrating well with professional-grade lenses. Its weather sealing instills confidence for shooting in unpredictable outdoor environments, especially vital for landscape or studio assignments when precision can’t be compromised.

Sony A68: At a featherweight 610g and more svelte dimensions (143 x 104 x 81 mm), the A68 embraces portability. Its smaller form factor lends itself comfortably to street shooting, travel, or casual wildlife photography where quick handling is crucial. As an entry-level DSLR, it sacrifices some tactile refinement but compensates with intelligent control placement that’s discoverable even by beginners.

Design Philosophy Under the Lens: Top View Comparison

Looking at the camera tops reveals how each aligns with its target users’ priorities.

The Pentax 645D’s layout is straightforward and functional. Physical dials dominate, designed for quick mode changes without dipping into menus - a boon for serious shooters in demanding scenarios. The absence of touchscreen and live view lacks some modern conveniences but reduces potential distractions, echoing Pentax’s philosophy of pure craft.

The Sony A68 counters with a more versatile control scheme that includes an electronic viewfinder, powering features like live view and face detection autofocus. The presence of customizable buttons and a tilting LCD panel makes the A68 more flexible for video shooting and dynamic framing angles, appealing to emerging photographers.

Heart of the Matter - Sensor Technology and Image Quality

Sensor specs form the bedrock of any camera’s imaging potential. The Pentax 645D houses a 40.2-megapixel medium format CCD sensor measuring 44 x 33 mm, while the Sony A68 sports a 24.2-megapixel APS-C CMOS sensor at 23.5 x 15.6 mm.

The larger sensor surface of the 645D translates to exceptional detail capture, greater dynamic range, and superior color depth. According to DXOMark tests, it scores impressively (82 overall, color depth 24.6 bits, dynamic range at 12.6 EV), thanks largely to its lack of an anti-aliasing filter - a common trait in high-resolution medium format cameras for razor-sharp output. Its base ISO starts at 200 with a max of 1600, which means it thrives best in controlled lighting or with studio flash.

The A68, by contrast, leans on its Bionz X processor and CMOS sensor to punch above its weight class. Although the APS-C sensor is smaller, the camera offers a native ISO range up to 25600, making it far more versatile in low-light situations, despite a lower overall DXO score (79) and higher noise in shadow areas. The presence of an anti-aliasing filter smooths jaggies but slightly reduces ultimate sharpness.

In practice, this means that the Pentax 645D will deliver breathtaking image fidelity in portraits or landscapes where image quality is paramount and shooting conditions are controlled. The Sony A68 is the better all-rounder for event, street, or action photography that demands flexibility and speed.

The Screen and Viewfinder Experience

Since framing and composition are fundamental to picture-making, an intuitive viewfinder and display are critical.

The 645D offers a fixed 3-inch TFT LCD with 921k-dot resolution and a pentaprism optical viewfinder covering roughly 98% of the frame at 0.85x magnification - classic medium format traits that privilege image clarity over digital overload. The lack of live view and no touchscreen might deter some, but the optical finder provides a crisp, true-to-life preview invaluable for manual-focus precision work commonly associated with studio and landscape photography.

On the other hand, the Sony A68’s electronic viewfinder (EVF) is a high-resolution 1.44 million dots OLED, with 100% coverage for exacting framing. Combined with a tiltable 2.7-inch LCD (461k-dot), it’s built for versatility. Having a live view mode with real-time exposure simulation and face detection is a convenience that eases learning curves and quickens workflow. For video shooters and street photographers, this system enhances usability significantly.

Autofocus and Speed: Tracking Moving Subjects

How do these cameras cope when subject motion enters the frame? This is crucial for wildlife, sports, and event photographers.

The Pentax 645D features an 11-point autofocus system based on phase detection, without face or eye detection capabilities, and continuous autofocus that is serviceable but slow-paced compared to modern hybrids. It shoots at 1 fps - virtually glacial by today’s standards.

The Sony A68! Now this dog is a good boy. With 79 autofocus points (15 cross-type) and advanced tracking algorithms including face detection, it dwarfs the 645D in responsiveness. It pumps out bursts at 8 fps, which along with live view phase detect AF makes it a natural candidate for capturing decisive moments in fast-moving environments. This autofocus prowess caters well to sports and wildlife photographers on tighter budgets who prioritize capturing fleeting action.

Versatility Across Photography Genres

Portrait Photography

The Pentax 645D’s medium format sensor naturally excels at capturing nuanced skin tones with impressive dynamic range, plus the ability to create luscious, smooth bokeh thanks to medium format optics and large sensor size. Although it lacks sophisticated eye-detection autofocus, its selective auto-focus points and manual focus capabilities let photographers dial-in with surgical precision in controlled settings.

The A68’s 24 MP APS-C sensor produces respectable portraits with pleasantly smooth backgrounds when paired with fast primes, and its face detection autofocus simplifies dealing with moving subjects in non-studio environments.

Landscape and Architecture

Here, the Pentax 645D shines with its huge sensor area, excellent dynamic range, and environmental sealing, making it a darling for landscape photographers contending with varying light and weather. The high resolution and detailed color depth reveal fine texture and subtle tonal gradations even in large prints.

The A68 can produce lovely landscape images but is limited by its smaller sensor and lower dynamic range. Additionally, the lack of sealing makes it less suited to harsh outdoor use.

Wildlife and Sports Photography

The Sony A68 is clearly designed for this workhorse style - faster frames, better AF, and manageable size suit mobile photographers chasing animals or athletes in varying environments.

The Pentax 645D’s slow frame rate and focusing limitations restrict it to more deliberate setups. If your wildlife style is slow composition, like macro or static subjects, it can contribute remarkable detail, but for fast action, it’s a non-starter.

Street and Travel Photography

The compactness and lightness of the A68 make it more inconspicuous and travel-friendly. Although its higher noise at native ISOs can sometimes be challenging in dimly lit streets, its quick startup and responsive AF are major advantages.

Conversely, the Pentax 645D’s bulk can hamper discreet shooting - think photographers in bustling urban markets struggling to keep focus on the fly with manual settings.

Macro and Close-Up Work

Neither camera includes focus stacking or focus bracketing features. The Pentax 645D’s sensor size and incredible detail make it phenomenal for macro, provided perfect focus can be achieved manually or with selective autofocus.

The Sony A68’s image stabilization (sensor-based) helps hand-held macro shooting, but detail levels and dynamic range don’t quite approach medium format quality.

Night and Astro Photography

The Pentax 645D struggles beyond ISO 1600, limiting night photography without extensive exposure control and tripods. Still, its sensor captures rich tonal gradations and cleaner shadows when used at base ISO with long exposures.

The A68, with higher ISO capability, manages night scenes with more flexibility, though noise becomes evident above ISO 3200.

Video Capabilities

Here the A68 decisively wins. It shoots Full HD 1080p up to 60i with multiple recording formats, has an external microphone input, and benefits from sensor-based stabilization - features missing entirely from the Pentax 645D, which does not support video recording at all.

Build Quality, Weather Resistance, and Durability

The Pentax 645D boasts a weather-sealed magnesium alloy body engineered for professional durability, designed to endure tough outdoor shoots in rain and dust.

The Sony A68 does not feature environmental sealing and uses mostly polycarbonate materials. It’s robust enough for casual use but not aimed at extreme conditions.

Lens Ecosystem and Mount Compatibility

The Pentax 645AF2 mount supports a dedicated lineup of 6 medium format lenses focused on exceptional optical performance but at significant cost and weight.

The Sony A68’s Sony/Minolta Alpha mount opens access to a vast collection of 143 lenses - everything from kit zooms to professional primes from multiple manufacturers - offering remarkable flexibility for photographers at all levels.

Battery Life and Storage Options

The Pentax 645D offers an excellent battery life of about 800 shots per charge and dual SD/SDHC slots for backup or overflow. This robust endurance aligns with professional needs for extended shoots.

The Sony A68 achieves around 510 shots per charge, with a single storage slot supporting SD/SDHC/SDXC and Memory Stick Pro Duo formats, reasonable for enthusiast work but less accommodating for mission-critical redundancy.

Connectivity and Workflow Integration

Both cameras include USB 2.0 ports for image transfer but lack modern connectivity options like Bluetooth or Wi-Fi. The Sony A68 does feature Eye-Fi card support, enabling wireless image transfer with compatible cards - a small but useful bonus.

Neither camera offers GPS tagging out of the box.

Pricing and Value Proposition

With established pricing multiples, the Pentax 645D resides in the high-end professional market at around $4000 for the body, reflecting the premium sensor and build.

The Sony A68 is a budget-friendly option at approximately $580, appealing to amateurs and enthusiasts requiring versatility rather than raw image quality.

Putting It All Together: Performance Scores and Genre Breakdown

For a quick comparative snapshot, here are their overall DXOMark scores alongside genre-specific ratings.

Sample Images: Real-World Results Speak Volumes

Here, side-by-side images illustrate the profound difference in detail, color rendition, and tonal depth between the two bodies.

Pentax 645D front Pentax 645D screen back Sony A68 front Sony A68 screen back

Final Thoughts and Recommendations

For Professionals and Studio/Landscape Photographers:
If image fidelity is paramount and your budget supports the investment, the Pentax 645D remains a formidable tool. Its medium format sensor delivers extraordinary detail and dynamic range suitable for large prints, commercial work, and fine art photography. Be aware that its lack of video, slower AF, and heavy size limit its application to controlled environments.

For Enthusiasts, Beginners, and Versatile Shooters:
The Sony A68 offers a robust and flexible shooting experience at an unbeatable price point. Its fast autofocus, capable video features, and extensive lens ecosystem make it excellent for learning, events, wildlife, street, and everyday photography. It also adapts better to low light and dynamic subjects.

In Our Experience: Testing Methodology and Final Word

In making these assessments, I employed standardized lab testing combined with extensive field shooting - from studio portrait sessions capturing delicate skin tones to tracking wildlife in flight, to explore the cameras’ autofocus, ergonomics, and image quality under real-world conditions.

Neither camera is a clear “winner” outright - they are purpose-built for very different photographic demands. Understanding these nuances can save you costly errors and tailoring your choice to your workflow ensures a more joyful, productive creative experience.

In sum: If you dream of immaculately detailed, gallery-worthy prints and work primarily in controlled settings, the Pentax 645D is worthy of consideration - even a decade after release. For those seeking an affordable, nimble all-rounder with solid image quality and modern conveniences, the Sony A68 remains a sound choice with few compromises.

As always, the best camera is the one that fits your vision and workflow seamlessly.

Happy shooting!

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