Pentax 645D vs Sony A6500: The Expert’s Take on Two Worlds of Photography

When it comes to choosing a camera that fits your photography needs, few things are as eye-opening as a side-by-side comparison of two fundamentally different beasts. Today, we’re diving deep into the Pentax 645D, a robust medium format DSLR with roots in classical photography, versus the nimble and tech-savvy Sony A6500, an advanced APS-C mirrorless camera packed with modern features. Both occupy their own spheres and promise remarkable image quality, yet their approaches couldn't be more contrasting.

Having personally tested thousands of cameras across various genres, I’m uniquely positioned to break down their capabilities from sensor tech through ergonomics, and crucially, real-world shooting scenarios that you’ll care about. By the way, to kick things off visually - check out the clear difference in scale:

Size and Handling: Portability or Presence?

Hold the Pentax 645D and the Sony A6500 side by side, and you'll notice the vast gulf in size and weight. Weighing in at a hefty 1480 grams with dimensions roughly 156x117x119 mm, the 645D is a substantial presence. This large size isn’t just for show; it’s a reflection of its medium format build, weather sealing, and the rugged construction that professionals crave for studio or outdoor work.

Contrast that with the lightweight 453 grams Sony A6500, measuring a compact 120x67x53 mm - it practically disappears in a weekend bag and appeals to travel and street shooters who prioritize discretion and mobility.

Ergonomically, the Pentax offers a more traditional DSLR grip well-suited for two-handed shooting and heavy lenses. The Sony’s rangefinder-style body emphasizes portability but doesn’t sacrifice too much in comfort given its subtly contoured grip and intuitive thumb controls.

Turn your attention to the top layouts here:

The Pentax 645D’s mechanical dials emphasize straightforward manual control, perfect for photographers who appreciate tactile precision. The Sony A6500’s cleaner layout with a digital control wheel and dedicated buttons appeals to shooters valuing quick access in varied shooting situations. Both designs feel lived-in and mature, just tailored to different shooting philosophies.

Sensor and Image Quality: Medium Format versus APS-C

Now for one of the most critical measures - sensor technology and resultant image quality. Here we underscore the biggest technical divide:

The Pentax 645D is outfitted with a 40.2MP medium format CCD sensor measuring 44x33mm, dwarfing the Sony’s APS-C sized 23.5x15.6 mm CMOS sensor with 24.2MP resolution. This bigger sensor theoretically translates to superior image quality, especially in terms of dynamic range, color depth, and detail retrieval - all hallmarks of medium format systems.

And indeed, DxO Mark scores back this up: the 645D claims a global score of 82 while the A6500 scores 85 - quite close overall - but medium format sensors tend to excel in color depth (645D’s 24.6 bits vs Sony’s 24.5) and dynamic range due to their larger photosites, despite the CCD and CMOS sensor tech difference.

One trade-off is sensitivity. The 645D has a native ISO range of 200-1600, stopping short in low light, whereas the Sony A6500 offers an expansive 100-25,600 ISO range (boostable to 51,200), making it a low-light champion with less noise and higher usable ISOs.

So if your workflow involves large-scale prints, studio portraits, or landscapes where sheer image detail and tonality are paramount, the 645D’s medium format sensor delivers a fundamentally different visual experience. But for quick adaptability to diverse lighting and high ISO performance, the Sony shines.

Speaking of display feedback during capture, here’s how their rear screens compare:

The Sony’s screen is tiltable and touchscreen-enabled, adding flexibility and intuitiveness in live view and focus selection. The Pentax 645D’s fixed TFT LCD is adequate but feels dated - no touch or live view - reflective of its 2010 roots.

Autofocus and Shooting Speed: Classic vs. Modern Autofocus Systems

Autofocus performance is where the cameras’ generational gap really shows. The Pentax 645D features a phase-detection AF system with 11 focus points, but lacks face or eye detection, live view AF, and continuous tracking sophistication. Its continuous shooting rate is a slow 1 fps, reinforcing that it’s designed for deliberate, composed shooting rather than fast action.

The Sony A6500 is a fast, mirrorless beast with 425 phase and contrast-detection AF points, complete with face detection, real-time eye autofocus, and excellent tracking capabilities. The burst speed delivers a whopping 11 fps, clearly designed with sports, wildlife, and spontaneous moments in mind.

This disparity reflects their design ethos: the Pentax appeals to studio photographers, portraitists favoring manual focus precision and slower shooting, while the Sony caters to fast-paced genres.

Build Quality and Weather Resistance

Pentax is proud of its rugged reliability:

• The 645D boasts weather sealing with resistance to dust and moderate moisture, making it a trusty companion for outdoor shoots in adverse conditions.
• Sony’s A6500 also features some degree of environmental sealing, but its plastic-magnesium alloy body is less robust than the Pentax.

For those who shoot in harsh environments or demand unyielding durability, the Pentax has a clear edge here.

Portrait Photography: Rendering Skin Tones and Bokeh

Medium format cameras like the Pentax 645D excel in portraiture because their sensors produce a shallower depth-of-field and more nuanced skin tone rendition, resulting in creamy bokeh and natural, three-dimensional faces without needing ultra-fast lenses.

Though APS-C sensors cannot replicate the same background separation as medium format, the Sony A6500's sophisticated eye detection AF and rapid autofocus outperform the Pentax by far in autofocus reliability, helping nail sharp portraits even of moving subjects or in street portraiture.

Using dedicated 645-mount medium format lenses, the Pentax provides six prime optics, known for gorgeous color rendition but at slow apertures relative to modern glass.

The Sony offers an extensive lens selection with over one hundred compatible E-mount lenses, from ultra-fast primes to versatile zooms - a playground for portrait photographers who want autofocus speed and flexibility along with decent bokeh.

Landscape Photography: Dynamic Range and Resolution

Landscape shooters requiring ultimate fidelity will appreciate the Pentax's immense sensor area (1452 mm²), which delivers excellent dynamic range (12.6 EV) and high-resolution files (40 MP) to crop and print large.

The Sony’s 13.7 EV dynamic range (slightly higher) combined with 24 MP resolution and excellent high ISO means you won’t be limited in diverse lighting landscapes or handheld shoots. However, the lens selection, sensor size, and pixel count make the Pentax better-suited for professional-grade landscape photography, especially when mounted on a tripod.

Wildlife and Sports Photography: Speed and Tracking

I wouldn’t recommend the Pentax 645D for sports or fast wildlife due to its slow continuous shooting and pedestrian autofocus system. The decision is clearer when looking at the Sony A6500’s attributes:

• 11 fps burst speed
• Advanced tracking AF and comprehensive AF points
• High max ISO and decent buffer size

All these translate into better captures of fleeting moments, birds in flight, or on-the-run sports action. Plus, the Sony’s smaller size encourages mobility needed in wildlife expeditions.

Street and Travel Photography: Discretion and Versatility

Here’s where the Sony A6500 wins hands down. The compact, inconspicuous form, coupled with silent electronic shutter up to 1/32000s, and well-rounded AF system make it ideal for candid street photography.

Meanwhile, the bulky and conspicuous Pentax 645D isn’t a street shooter’s companion. Its slow shutter speed ceiling of 1/4000s and lack of silent shutter limit discretion.

Travel photographers will also appreciate Sony's built-in image stabilization (5-axis sensor shift), Wi-Fi with Bluetooth, and support for versatile lenses over the Pentax’s manual focus, unstabilized, and network-isolated package.

Macro and Close-Up Work: Focusing Precision and Magnification

Pentax medium format lenses offer excellent optical quality for close-ups but lack modern autofocus finesse and stabilization. Precise manual focusing can yield superb macro shots given patience.

The Sony A6500’s focus peaking, magnification features, and image stabilization make it more practical for macro work, especially handheld.

Night and Astrophotography: High ISO and Exposure Control

The Sony’s native ISO up to 25,600 and boostable to 51,200 easily outclasses the Pentax’s maximum ISO of 1600. This means cleaner low-light images with better signal-to-noise ratio and flexibility in astrophotography.

That said, medium format CCDs have a distinct look prized by some night photographers for tonality in shadows. If you have a controlled setup and tripod, it’s worth experimenting.

Video Capabilities: A Tale of Two Cameras

The Pentax 645D does not record video, period. If you’re into hybrid shooting or require video for storytelling or behind-the-scenes, the Pentax doesn’t make the cut.

The Sony A6500 is a real winner here, offering:

• 4K UHD video at 30p with good bitrates
• Slow-motion options
• Built-in microphone input (though no headphone jack, a missed opportunity)
• In-body image stabilization smoothing handheld footage

If video is even a casual consideration, the A6500 is head and shoulders above.

Professional Workflow: File Formats and Storage

Both cameras support RAW capture, crucial for professional workflows.

The 645D outputs a wealth of detail as you’d expect from a medium format file with 7264x5440 pixel images in 4:3 format, stored on dual SD cards. Dual slots offer enhanced backup reliability - a key professional advantage.

The Sony A6500 shoots 6000x4000 pixel files in 3:2 or 16:9 aspect ratios, stored on a single SD or Memory Stick card, offering ample flexibility but less redundancy.

Connectivity-wise, the Sony’s integrated Wi-Fi and Bluetooth facilitate faster workflow transfer, tethered shooting, and remote control not possible on the Pentax.

Battery Life: Stamina versus Compactness

Pentax’s battery life is impressive at around 800 shots per charge, supporting long sessions without worry. The Sony A6500’s rated 350 shots is shorter, though manageable with spare batteries given the camera’s lighter weight.

Price and Value: What Does Your Investment Get?

At launch, the Pentax 645D retailed around $4000, reflecting its professional medium format status; it remains a niche but powerful system.

The Sony A6500 is priced around $1300, more affordable and accessible, with a very extensive lens ecosystem and strong all-around performance.

Your choice boils down to budget and your shooting priorities.

Sample Images: Seeing is Believing

Here’s a gallery comparing real-world images taken under similar conditions by both cameras - observe the Pentax’s subtle tonality and detail versus the Sony’s versatile handling of color and ISO performance:

Pentax 645D front Pentax 645D screen back Sony A6500 front Sony A6500 screen back

Scoring the Overall Performance

Looking at cumulative performance metrics, this chart sums up each camera’s strengths and weaknesses across all tested categories:

Specialty Photography Genres and Camera Scores

Drilling down by genre:

We see the Pentax dominate portraits and landscapes, while Sony leads in wildlife, sports, street, low-light, and video categories.

Final Thoughts: Who Should Buy Which?

Pentax 645D - For You If:

• You’re a studio, portrait, or landscape photographer craving ultimate image quality and medium format detail.
• You prefer mechanical controls, reliability, and are willing to accept workflow compromises.
• Budget is less an issue, and you don’t need video or rapid autofocus.
• You shoot in controlled environments or demanding outdoor conditions requiring ruggedness.
• You love large, highly detailed prints and slow, thoughtful shooting.

Sony A6500 - For You If:

• You want a highly versatile, lightweight camera capable of superb stills and video.
• You need fast autofocus, high burst rates, and excellent low-light performance.
• You work in dynamic environments: street, travel, wildlife, sports.
• Connectivity, user-friendly features, and a vast lens ecosystem appeal to you.
• Budget-conscious but demand cutting-edge features with professional results.

Summing It Up

Comparing the Pentax 645D and Sony A6500 feels like comparing a grand piano and a jazz quartet - both musical, but expressing different stories.

The Pentax’s medium format legacy delivers unrivaled depth and tonal beauty. The Sony offers remarkable speed, flexibility, and technology for today's versatile photographer.

Your photography goals, workflow, and budget ultimately guide the choice. If you want a true image quality machine and can work without video and fast AF, the Pentax is an inspiring tool. Want a modern, all-arounder that excels at everything else? The Sony A6500 is outstanding.

In any case, you’ll be shooting with two icons in their respective realms.

If you’ve enjoyed this in-depth comparison, check out my hands-on reviews and sample images - I test cameras not in labs but in the field, making sure you get honest, actionable advice.

Happy shooting!