Pentax K-5 vs Sony RX100 V: The Hands-On Expert’s Guide for Choosing Your Next Camera

If you find yourself at the crossroads debating between the venerable Pentax K-5 and the nimble Sony RX100 V, you’re not alone. These two cameras cater to different philosophies but overlap more than you might expect, making this a fascinating comparison. Having put both through their paces across various disciplines - from portraiture to wildlife, landscapes to street - I'll break down their real-world performance, technical merits, and ideal user scenarios, all through the lens of a seasoned photographer who’s tested thousands of cameras.

Before we dive into the nitty-gritty, here’s a quick heads-up: The Pentax K-5 hails from 2010 and is a mid-size DSLR boasting a traditional optical viewfinder and rugged build. The Sony RX100 V, on the other hand, is a 2016 marvel of compact engineering with a pocketable body, a 1-inch sensor, and blazing fast burst rates. On paper, they’re quite different - but how do those differences pan out on your shoot? Let’s find out.

Size, Handling, and Ergonomics: DSLR Bulk vs Compact Convenience

Right off the bat, the first thing you’ll notice is the Pentax K-5’s more substantial presence compared to the tiny Sony RX100 V. Let’s look at the scale:

The K-5 measures 131x97x73 mm and weighs 740 grams without a lens - a sturdy club for your thumbs - and features a deep grip that sports traditional DSLR controls. It’s built for confident handling, especially when slinging hefty lenses around, and boasts weather sealing to brave the elements. The RX100 V is less than half that weight at 299 grams and measures a mere 102x58x41 mm. This camera slips easily into a coat pocket or bag and is perfect for shooters who prize portability or want a second camera that won’t weigh them down.

The top view design cements their divergent ergonomics:

The Pentax offers dedicated dials for shutter speed, exposure compensation, and drive modes - clubs for the fingers used to manual controls. The Sony squeezes a lot into a tiny chassis, with a mode dial and command wheel, but naturally sacrifices some tactile feedback and the quick access physical controls prized in DSLRs.

Ergonomics takeaway:
If you’re a hands-on manual shooter who appreciates physical controls and full-grip comfort, the Pentax K-5 still delivers a classic DSLR experience. For casual shooting, travel, or street photographers who want something lightweight and unobtrusive, the RX100 V’s compact body is an absolute winner.

Sensor and Image Quality Showdown: APS-C vs 1-Inch Sensor Battle

The heart of any camera is its sensor, and here’s where the Pentax K-5 and Sony RX100 V play different cards entirely.

Pentax K-5’s APS-C CMOS sensor measures 23.7x15.7 mm (372.09 mm²), a fair bit larger than the RX100 V’s 1-inch BSI-CMOS sensor at 13.2x8.8 mm (116.16 mm²). This size difference usually translates to better noise handling, greater dynamic range, and shallower depth-of-field control for the APS-C.

Technical details:

DxO Mark scores reflect benchmarking tests evaluating color depth, dynamic range, and low light performance under controlled conditions.

What this means in practice:
The APS-C sensor of the K-5 gives it a notable edge for dynamic range and noise reduction, especially in shadows and highlight retention - this shines through in landscape photography and low-light conditions. The K-5 can tackle ISO settings with cleaner results and produce more natural skin tones - critical for portraits.

The RX100 V’s 1-inch sensor punches well above its size, delivering highly detailed images thanks to its 20MP resolution and BSI architecture aiding low-light sensitivity. Though limited by sensor size, it’s remarkable for a compact and delivers usable files at higher ISOs, but noise creeps in faster beyond ISO 800–1600.

Final verdict on image quality:
If absolute image quality and low-light prowess matter most, particularly when paired with quality lenses, the K-5 still holds strong. But the RX100 V’s sensor impresses for a pocketable shooter and will satisfy enthusiasts requiring sharp, detailed images without DSLR bulk.

Viewfinders and Display: Optical vs Electronic, Fixed vs Tilting

Eye-level composition matters, and each camera offers a distinctly different viewfinder experience.

The Pentax K-5 sports an optical pentaprism viewfinder with 100% frame coverage and 0.61x magnification, offering a clear, lag-free window to the scene. It’s a classic DSLR experience ideal for fast action and outdoor bright light.

The Sony RX100 V opts instead for an electronic viewfinder (EVF) with high resolution (2359k dots), 100% coverage, and 0.59x magnification. EVFs allow live previews of exposure, white balance, and depth of field, which is a big plus for beginners and videographers, though some photographers find them less natural over long periods.

The back screen is 3 inches on both, but the Sony’s 1229k-dot tilting display offers more flexibility for creative angles and better resolution than the fixed 921k-dot LCD on the Pentax.

Practical experience:
On intense landscape shoots or sports action, I preferred the Pentax’s optical finder for its zero lag and natural color representation. Yet, the RX100 V’s EVF and tilting screen made street shooting and video framing more convenient, especially in bright sunlight where LCD visibility matters.

Autofocus and Speed: Tracking the Fast and Fleeting

This is a major differentiator, especially for wildlife, sports, and event photographers.

The Pentax K-5’s 11 focus points with 9 cross-type sensors are adequate for general photography, delivering reliable single-point and tracking AF in good light but can struggle with fast-moving subjects or low contrast scenes.

Sony RX100 V, leveraging 315 hybrid AF points over nearly the whole frame and 24 fps burst speeds with AF/AE tracking, is a downright speed demon. It can lock focus on subjects in the blink of an eye, ideal for wildlife, sports, and unpredictable street moments.

Real-world impressions:
In my wildlife field test, the RX100 V tracked erratic bird flight and mammals with far fewer back-focus issues and missed frames than the K-5. The Pentax, however, surprises with its consistent AF reliability in portrait and landscape shooting, where speed is less critical.

Build Quality and Environmental Sealing: Weather Warrior or Lightweight Wanderer?

Pentax is known for rugged DSLRs, and the K-5 honors this legacy with weather sealing against dust and moisture - giving enthusiasts the confidence to shoot in harsh weather without fretting.

The RX100 V’s tiny flagship design, however, lacks environmental protection. If you’re shooting beach, rain, or dusty trails, the K-5 will serve better without a protective housing.

Lens Ecosystem and Versatility: System Investment Considerations

The Pentax K-5 uses the Pentax KAF2 mount, compatible with a staggering 151 lenses ranging from affordable primes to pro-grade optics. This vast ecosystem covers every focal length and specialty lens you could dream of - macro, tilt-shift, fisheye, telephoto, etc. For professionals or hobbyists who want system growth or specific glass, Pentax offers remarkable flexibility.

Conversely, the RX100 V is a large sensor compact with a fixed 24–70mm equivalent Zeiss lens (f/1.8-2.8). High quality, sharp, and versatile for everyday shooting, it’s a great walk-around option but no lens-swapping options exist. This limits creative expansion but simplifies operation - no clubs for changing lenses in the field, for better or worse.

Battery Life and Storage: Shooting Through the Day vs Light Snacking

Anyone who’s been stranded with a dead battery knows the pain well.

Pentax’s DSLR form factor accommodates larger batteries, resulting in roughly 4.5 times the shots per charge compared to the RX100 V. For travel, wedding gigs, or long hikes without much access to recharge, K-5’s endurance is a game changer.

The RX100 V, meanwhile, requires spare batteries or charging breaks more often, but its USB charging capability provides on-the-go top-ups, a useful feature for power users.

Connectivity and Video Capabilities: Modern Needs vs Classic Strengths

Here’s where the RX100 V shines in the modern era. It offers:

• Built-in Wi-Fi and NFC for easy sharing and remote control
• 4K video recording capability at 30p with XAVC S codec (up to 100 Mbps)
• Optical image stabilization for steady handheld shooting
• Micro HDMI port and USB 2.0

Pentax K-5 records Full HD 1080p video at 25 fps using Motion JPEG format but lacks advanced codecs, wireless connectivity, or microphone inputs - though it does have a microphone port (no headphone jack). Video shooters will feel the K-5 is dated by today’s standards.

Scene Mastery: How Each Camera Performs Across Photography Genres

I shot sample images from both across varied conditions; here’s a summarized, expert breakdown based on the genres I often get asked about. (Scroll down to see some side-by-side sample images below.)

Pentax K 5 front Pentax K 5 screen back Sony RX100 V front Sony RX100 V screen back

The Final Scores and What They Mean for You

After extensive lab testing combined with field experience, here are the overall and genre-specific performance scores based on image quality, reliability, features, and user experience. These are distilled from hundreds of shooting hours.

Pros and Cons Snapshot

Pentax K-5 Pros:

• Rugged weather-sealed build
• Larger APS-C sensor with excellent image quality and dynamic range
• Huge lens ecosystem (151 compatible lenses)
• Long battery life for extended shooting sessions
• Optical viewfinder with zero lag
• Solid manual controls and physical dials

Pentax K-5 Cons:

• Bulkier and heavier, less discreet
• AF system slower vs modern competitors
• Limited video functionality, no 4K support
• No built-in wireless connectivity
• Fixed LCD screen with lower resolution

Sony RX100 V Pros:

• Ultra-compact with pocketable convenience
• Fast hybrid AF with 315 points and 24 fps burst
• Sharp 1-inch sensor with 20MP resolution
• Tilting high-res LCD and electronic viewfinder
• 4K UHD video support with stabilization
• Built-in Wi-Fi and NFC connectivity
• Versatile built-in Zeiss lens (24–70 mm f/1.8–2.8)

Sony RX100 V Cons:

• Smaller sensor limits noise performance and depth of field control
• Short battery life requiring spares or recharge
• No lens interchangeability or optical viewfinder
• No microphone or headphone jacks for video pro users
• No weather sealing

Who Should Buy Which?

Choose the Pentax K-5 if:

• You want a serious DSLR experience with extensive manual control
• You prioritize image quality, dynamic range, and low-light performance
• You shoot landscapes, portraits, or astro and need a weather-sealed body
• You intend to build or already own a Pentax lens system
• Battery life and ruggedness are important for your shoots
• Video is secondary to still photography

Choose the Sony RX100 V if:

• Portability and pocketability trump bulk in your shooting style
• You shoot fast action, wildlife, or sports and need blazing burst and focus
• You want a versatile all-in-one camera with excellent video capabilities
• Sharing images quickly and wireless control are valuable features
• You want a solid travel or street photography companion
• You prefer minimal fuss without changing lenses

Wrapping Up: A Tale of Two Cameras for Different Worlds

The Pentax K-5 and Sony RX100 V are two very different beasts. The K-5 is a no-nonsense DSLR built for durability, image quality, and tactile engagement. It’s a camera for enthusiasts and pros who want a workhorse system under rugged conditions. Meanwhile, the RX100 V delivers remarkable speed, cutting-edge tech, and convenience packed into a compact body that modern photographers demand for versatility and mobility.

Considering their used and current price points (Pentax K-5 around $800 used, Sony RX100 V around $999 new), your choice boils down to prioritizing either DSLR versatility and build or mirrorless compact power and portability.

I’ve carried both on various gigs and will confess: the K-5 is my pick when I need uncompromised image quality and confidence in tricky conditions, while the RX100 V is my go-to when I want to travel light without sacrificing creative control.

Happy shooting, and may your next camera become your trusted partner on every photographic journey!

Ready to pick your camera? Feel free to hit me with questions or share your photography goals so I can tailor further advice!