Pentax K-5 IIs vs Sony QX100: A Hands-On Comparison for Photography Enthusiasts

Choosing between a traditional DSLR like the Pentax K-5 IIs and a compact, lens-style camera such as the Sony QX100 is a fascinating challenge. They represent distinctly different philosophies and cater to divergent photographic needs. Having tested thousands of cameras in varied settings - from studio portraits to rugged landscapes - I'll walk you through how these two compare in real-world performance, technical merit, and value. By the end, you'll understand not just which camera is “better” on paper, but which feels right in practice.

First Impressions: Size, Handling, and Build Quality

For starters, the physical difference is striking.

The Pentax K-5 IIs is a mid-size DSLR, weighing about 760 grams with dimensions of 131x97x73mm. It feels substantial and robust in the hand. Pentax has a reputation for solid build quality, and this model delivers a comfortable grip backed with impressive weather sealing - dustproof and partially weather-resistant - to keep you shooting in challenging outdoor conditions.

Conversely, the Sony QX100 looks like a tiny lens - because it essentially is a lens-style camera without its own viewfinder or screen. Weighing merely 179 grams and measuring 63x63x56 mm, it’s designed to be paired with a smartphone, relying on that device for composing, settings, and image review. It’s light and highly portable but less rugged, lacking any environmental sealing.

The Pentax sports a traditional DSLR top plate with clearly laid out dials and buttons, facilitating quick manual exposure changes - ideal for seasoned photographers who crave tactile control and speedy access without diving into menus. The Sony QX100 loses this tactile immediacy for compactness, with most control handled through its app interface via the connected phone.

My take: If you prioritize ergonomics, extensive physical controls, and durability, the K-5 IIs immediately wins. The QX100 leans toward casual or travel shooters who want clean photos without the bulk of a camera body.

Sensor Comparison: APS-C Meets 1-Inch BSI CMOS

Sensor size and technology significantly influence image quality, dynamic range, and noise performance.

• Pentax K-5 IIs: An APS-C sized CMOS sensor measuring 23.7x15.7mm (372.1 mm² sensor area) with 16MP resolution. Notably, it omits the usual anti-aliasing (low-pass) filter, which Pentax used to boost sharpness and micro-detail. In practical testing, this results in exceptionally crisp stills especially when paired with sharp prime lenses.

• Sony QX100: Uses a 1-inch BSI-CMOS sensor (13.2x8.8mm, 116.2 mm²) at 20MP resolution. Thanks to backside illumination (BSI) technology, it performs well in low light compared to many other compact sensors, but the physical size still constrains dynamic range and noise compared to APS-C.

In side-by-side comparisons in good lighting, the Pentax delivers richer tonality and superior dynamic range, especially in recovering highlights and shadows in landscape scenes. The QX100’s images are clean and punchy but tend to clip highlights quicker and exhibit more noise at ISO 1600 and beyond.

Shooting Experience: Autofocus and Viewfinder

The K-5 IIs features an 11-point autofocus system including 9 cross-type sensors, supporting phase-detection autofocus with live view contrast detection. Its tracking and continuous AF modes hold focus well in moderately fast action, though not at the bleeding edge of autofocus technology given its 2013 vintage.

Face detection is basic but effective, though no animal eye AF is present. Sony’s QX100, unfortunately, lacks phase detect AF altogether and relies solely on contrast detection. This results in slower acquisition and less reliable focus tracking - unsurprising given the compact form factor.

Since the QX100 lacks an electronic or optical viewfinder, you compose exclusively via your smartphone or tablet’s LCD, which introduces latency and potential connection drops - something serious photographers know to avoid.

Pentax comes with a fixed 3-inch 921k-dot TFT LCD screen for image playback and live view, while the Sony lacks any built-in screen. The interface on the K-5 IIs feels classic DSLR, firm and dependable; in contrast, the QX100’s touchscreen responsiveness varies with smartphone workload and app optimization.

Versatility Across Photography Genres

Both cameras embrace different segments, but I’ve put them through tests across a swath of popular photography genres.

Portrait Photography

Portraits demand accurate skin tones, fine detail, and smooth bokeh.

The Pentax K-5 IIs, paired with fast Pentax primes, renders skin tones naturally with pleasing tonal gradation. The absence of an AA filter sharpens facial features without introducing moiré. Combined with Pentax’s in-camera sensor-shift stabilization and reliable face-detection AF, you get consistent, sharp portraits especially in daylight or studio settings.

The Sony QX100’s 28-100mm F1.8-4.9 lens offers versatility, but the smaller sensor struggles to separate subject from background as effectively. Bokeh is decent but somewhat busy compared to the creamier quality from APS-C glass on the Pentax. Face detection on the QX is limited and less reliable, which hampers portrait precision especially in dimmer light.

Landscape Photography

Landscape lovers crave high resolution, dynamic range, and weather durability.

Here, the Pentax K-5 IIs shines. Its 14.1 EV dynamic range score on DXOMark allows recovering shadows and highlights better than the QX100's 1-inch sensor. The rugged build and weather sealing mean you can confidently shoot in mist, rain, or dusty environments.

The Sony QX100’s compactness makes it easy to carry for casual landscape shots on travel; however, its smaller sensor limits ultimate image quality, and the lack of sealing means you must be cautious in harsh conditions.

Wildlife and Sports Photography

Speed and autofocus tracking matter most here.

With 7 fps continuous shooting and respectable AF tracking, the Pentax K-5 IIs holds up decently for mid-level sports and wildlife photography. But remember, 11 focus points lag behind current standards.

The QX100 does not offer burst mode or fast AF tracking - its shooting speed and focusing behavior are too sluggish for serious action. I would not recommend it for any demanding wildlife or sports shoot. The K-5 IIs, meanwhile, offers a more professional experience in this arena.

Street Photography

For candid, discreet shooting on the streets, size and silence count.

The K-5 IIs isn’t tiny, but its 8000 max shutter speed and relatively quiet internal shutter help reduce distractions. However, its bulk makes it less stealthy.

The Sony QX100 wins on portability with a minimal footprint and wireless control from your phone. However, you sacrifice immediacy and good ergonomics. Self-timers and remote shooting modes are handy, but the lack of physical controls can slow you down when a quick reaction matters.

Macro and Close-Up

The QX100 can focus as close as 5cm, which is excellent for casual macro shots on the go. Pentax’s lenses include superb macro options, and with sensor-based in-body stabilization, you can get tack-sharp close-ups, albeit at the cost of increased bulk.

Night & Astro

Here’s where sensor size really shows.

The Pentax K-5 IIs excels with clean high ISO performance, low noise at 3200 and 6400 ISO, and a sturdy tripod mount. Astro and night photographers benefit from low light AF, long exposures, and sensor-based IBIS to stabilize shots.

The QX100, with its 1-inch sensor and respectable ISO 6400 max, delivers surprisingly usable night images for a compact. But beyond ISO 1600-3200, noise becomes a limiting factor.

Video Capabilities

Let’s talk video.

• Pentax K-5 IIs records Full HD 1080p at 25 fps in Motion JPEG (MJPEG) format. While fine for casual clips, MJPEG files are bulky and editing flexibility is limited versus modern codecs. It lacks features such as 4K, mic/headphone jacks, or advanced stabilization in video mode.

• Sony QX100 shoots 1080p 30fps in MPEG-4, delivering decent quality video primarily driven by its lens's optical stabilization. However, no mic input or headphone monitoring limits audio control.

If video is a priority, neither is ideal, but the K-5 IIs offers more flexibility for stills-centric creators.

Travel and Everyday Use

Compactness and convenience are key when you’re exploring.

The Sony QX100’s tiny size and wireless connectivity, including NFC, make it easy to slip in your pocket and share images instantly through your smartphone. Unfortunately, its battery life is limited to about 200 shots per charge - a downside for long days out.

Pentax’s larger camera is heavier and bulker, but with excellent 980-shot battery life and weather sealing, it adapts better to extended outings, including rugged environments. Storage options are straightforward with a single SD slot.

Professional Work Flow

For studio or editorial purposes, RAW support, color depth, and precise control count.

The K-5 IIs delivers 16-bit RAW files supported by robust Pentax lenses, with clean files for post-processing. Its color depth is a strong 23.9 bits, and dynamic range is very respectable.

The Sony QX100 does not support RAW, only JPEG, significantly limiting professional post-production flexibility. Its color depth and dynamic range metrics are not available, but likely inferior given sensor size and compression.

Technical Underpinning and Connectivity

• Pentax K-5 IIs: Uses a Prime II processor. Though dated, it delivers reliable performance. Sensor-shift in-body image stabilization is a huge plus, usable with any lens. Connectivity options include USB 2.0 and HDMI ports, but noticeably lacks built-in wireless - GPS is optional.

• Sony QX100: Wireless connectivity is built-in, designed for wireless shooting and sharing via your smartphone app - great for casual social sharing. However, absence of HDMI or mic jacks limits video workflows. Battery charging via USB is convenient though battery life remains the limiting factor.

Pricing and Value Considerations

At launch, the Pentax K-5 IIs retailed at about $749, reflecting its serious feature set and build quality. The Sony QX100 came in around $268, targeting a budget-minded segment seeking ultra-portability without serious manual controls or professional-grade image quality.

For your dollar, the Pentax gives you undeniable value if you want a capable DSLR with pro-level stills and reasonable video support. The Sony appeals to those who prioritize convenience and smartphone integration above all else.

Pentax K 5 IIs front Pentax K 5 IIs screen back Sony QX100 front Sony QX100 screen back

Evaluating Performance Scores

To bring it all home, the K-5 IIs earned an impressive DXOMark overall score of 82, with standout marks in color depth and dynamic range. The QX100 hasn’t been DXO tested officially, but it objectively falls short due to sensor constraints and imaging pipeline.

Strengths Visualized by Genre

Final Thoughts: Which One Should You Choose?

My experience testing these side-by-side makes the decision relatively straightforward but hinges heavily on your photographic priorities.

• Choose the Pentax K-5 IIs if:

  • You want a versatile DSLR capable of high-quality images across all genres, particularly portraiture, landscapes, and low-light photography.
  • You value solid ergonomics, robust environmental sealing, and long battery life.
  • You desire full manual controls, RAW image flexibility, and a supportive lens ecosystem (151 Pentax K-mount lenses).
  • You shoot bursts regularly and need reliable AF tracking.
  • Video is secondary, but occasional Full HD recording is a bonus.

• Choose the Sony QX100 if:

  • Portability, integration with your smartphone, and sharing convenience top your list.
  • You pursue casual photography with occasional macro or travel snaps.
  • You can accept limited manual control, slower autofocus, and only JPEG output.
  • Battery life and limited environmental protection aren’t deal breakers.
  • You want cutting-edge sensor tech in a lens-style form factor and enjoy remote shooting.

A Personal Recommendation

For enthusiasts or professionals who seek a daily driver with well-rounded capabilities, the Pentax K-5 IIs remains a compelling choice despite its age, especially considering the price-to-performance ratio.

The Sony QX100, although innovative and fun, feels more like a niche gadget for convenience shooting or smartphone users wanting better optics than their built-in cameras. If you want serious image quality and creative control, it won’t satisfy.

In summary, choosing between these two isn’t about which has a larger megapixel number or the flashiest specs. It’s about what kind of photography experience you want, how much manual oversight you crave, and what fits your workflow and budget.

Armed with this detailed comparison and my years of hands-on testing, you can confidently decide which camera matches your vision.

Happy shooting!