Olympus TG-810 vs Pentax K-5 IIs: A Hands-On Comparative Review for Enthusiasts and Professionals

Photography gear can’t be one-size-fits-all. That much is clear when you pit a rugged waterproof compact like the Olympus TG-810 against a highly capable mid-size DSLR such as the Pentax K-5 IIs. These two cameras come from very different eras and design philosophies - one built for adventure and durability, the other engineered for image quality and creative flexibility. Having put both through their paces over countless test sessions and real-world shoots, I’m excited to share a detailed, experiential comparison that will help you choose the right tool for your photographic journey.

Before diving into the nitty-gritty, let's get a sense of their physical presence and handling.

Handling and Ergonomics: Compact Ruggedness vs DSLR Bulk

The Olympus TG-810 is military-grade ruggedness wrapped in a petite compact body. Weighing just 215 grams and measuring 100 x 65 x 26 mm, it slips comfortably into a jacket pocket or backpack side pouch. Its fixed lens design eliminates thinking about glass swaps, making it an ideal grab-and-go camera for casual shooters or outdoor enthusiasts who want something that survives a plunge into water or a drop on rough terrain.

Contrast that to the Pentax K-5 IIs, a mid-sized DSLR tipping the scales at 760 grams with dimensions of 131 x 97 x 73 mm - an instant reminder it’s designed for serious photographers who prioritize control and durability over pocketability. The K-5 IIs features an all-weather sealed magnesium alloy body well-suited for inclement conditions, though it requires a dedicated bag or strap for carrying all day.

The control layout on the K-5 IIs is thoughtfully organized with dedicated dials and buttons geared toward rapid manual adjustments. Olympus’s TG-810, by necessity, compromises on direct control with a minimalistic button interface and no manual exposure modes, focusing instead on user-friendly automation and reliability in tough environments.

Ergonomically, I found the TG-810’s fixed lens and small form reassuring for fast outdoor shooting, but its rear buttons and non-touchscreen, though adequately responsive, felt cramped after longer sessions. The K-5 IIs’ generous grip and physical controls, including dedicated exposure compensation and ISO buttons, shine for pro workflows and extended handheld usage.

Sensor and Image Quality: From Compact CCD to APS-C CMOS Brilliance

The heart of any camera’s imaging prowess is its sensor. The TG-810 uses a legacy 1/2.3-inch 14MP CCD sensor measuring just 6.17 x 4.55 mm, whereas the K-5 IIs sports a significantly larger APS-C CMOS sensor of 16MP, sized 23.7 x 15.7 mm. That’s nearly a 13-fold increase in sensor area, one of the biggest factors influencing image quality, dynamic range, and low-light performance.

The small sensor with CCD architecture in the TG-810 delivers reasonable results under good lighting, but it falls short in noise control and latitude compared to modern CMOS sensors. The K-5 IIs’ sensor is notable for lacking an anti-aliasing (AA) filter, a controversial choice that boosts resolving power but can risk moiré in patterns. This decision makes the K-5 IIs punch well above its weight in sharpness and detail preservation.

In my lab testing with standardized scenes, the K-5 IIs consistently captures finer textures and balanced tonal transitions, particularly in shadow details and highlight roll-off. The TG-810’s images exhibit more grain and limited dynamic range, which is expected given its smaller sensor and older chip. The Pentax also utilizes a PRIME II processor, which works smoothly with the CMOS’s data throughput, while the TG-810’s TruePic III+ processor from 2011 shows its age in slower image rendering and muted color depth.

Viewfinder and LCD: Reality Check in Framing and Review

Neither camera includes a touchscreen, but their approach to composing and reviewing images diverges strongly.

The TG-810 has a 3-inch fixed TFT Hypercrystal III LCD with a 920k-dot resolution. It’s bright and viewable under most outdoor conditions but lacks a viewfinder entirely, demanding reliance on the rear screen which can hamper precise framing in strong sunlight. For casual and adventurous shooters, this is adequate but not inspiring.

Conversely, the K-5 IIs boasts a full pentaprism optical viewfinder with 100% frame coverage and 0.61x magnification - ideal for critical manual composition in variable lighting. The same 3-inch TFT LCD on the back complements the optical viewfinder well for reviewing shots and navigating menus.

For those who prefer an optical viewfinder to compose in any light, the K-5 IIs is a clear winner. The TG-810’s screen works well in its small-sensor compact category but doesn’t rival DSLR clarity or feedback.

Autofocus Systems: Speed vs Simplicity

Autofocus can make or break your ability to capture fleeting moments. The TG-810’s autofocus is contrast-detection based with face detection but no manual focus control. It’s reliable enough for stationary subjects and basic pinpoint focusing down to 3cm macro but lacks tracking sophistication or continuous autofocus (AF-C) for motion.

The K-5 IIs features a robust 11-point phase-detection autofocus system with 9 cross-type sensors, enabling fast, precise focus acquisition and tracking. It offers AF modes including single, continuous, selective point, and face detection suitable for varied scenarios. Manual focus is supported via the extensive Pentax K-mount lens ecosystem, allowing tactile control absent from the Olympus.

In high-stakes wildlife or sports shoots, I found the K-5 IIs dramatically outpaced the TG-810, locking focus consistently on moving subjects. The Olympus fixed zoom lens’s slower aperture range (f/3.9–5.9) and simpler AF system limit its performance in low light or action.

Burst and Shutter Capabilities: Snapshots vs Action

Burst rate is critical for sports and wildlife - the TG-810 manages a sluggish 1 fps continuous shooting, more geared to snapshots than sequences. The Pentax, however, offers a respectable 7 fps burst with buffer depth suitable for sequence shooting and tracking motion.

Shutter speed options further drive this contrast. The TG-810 maxes out at 1/2000s and goes as slow as 4 seconds, whereas the K-5 IIs extends the range from 30 seconds to 1/8000s, with full manual exposure options. The K-5 IIs also supports shutter priority, aperture priority, and full manual exposure control - not present on the Olympus.

Photographers looking to capture fast action or experiment with lighting and motion effects benefit from Pentax’s superior shutter versatility and higher frame rates.

Lens Ecosystem and Versatility: Fixed vs Interchangeable

Lens availability is a cornerstone of photographic creativity. The TG-810’s built-in zoom provides an equivalent 28-140 mm range with a 5x zoom at f/3.9–5.9 aperture. While decent for casual shooting and basic framing flexibility, it’s a fixed lens that can’t be swapped or upgraded.

The Pentax K-5 IIs accepts the extensive Pentax KAF2 mount lineup, offering 151 lenses at last count - from ultra-wide primes to super telephotos, fast portraits lenses to modern macro optics. This system flexibility grandly expands the K-5 IIs’ application horizon well beyond what the TG-810 is built for.

Durability and Environmental Protection

If ruggedness is your priority, particularly for travel or outdoor adventures, the TG-810 is a tank: waterproof to 10 meters, freezeproof to -10°C, shockproof from 2 meters, and dustproof. It even includes GPS for geotagging outdoor shots - a thoughtful addition for hikers or explorers.

The K-5 IIs, while weather-sealed against moisture and dust, is not rated waterproof, crushproof, or freezeproof. It demands more care and protective accessories outdoors but offers balanced durability suited to professional outdoor work in less extreme conditions.

Battery Life and Connectivity: Staying Powered and Connected

Here the K-5 IIs pulls ahead with a massive 980-shot battery life rating versus the TG-810’s more modest 220 shots. For anyone shooting long days in the field, this difference is pronounced. The DSLR’s larger battery pack (D-LI90) delivers endurance that reduces the need to carry spares.

On connectivity, the TG-810 has built-in GPS and supports Eye-Fi cards for wireless image transfer, a neat combo for instant field sharing. The K-5 IIs lacks native wireless but features a microphone port and HDMI output tailored to more involved workflows.

Video Capabilities: Lightweight HD vs Professional Options

Video on the TG-810 maxes out at 720p 30fps, recorded in MPEG-4 or H.264 formats. It’s suitable for casual clips and documenting adventures but limited by fixed aperture and onboard microphone only.

Pentax’s K-5 IIs offers Full HD 1080p at 25fps with Motion JPEG compression. It includes a microphone input for external audio - a significant advantage for more serious videographers. However, its frame rate limit and absence of 4K means it’s best for occasional cinema needs rather than dedicated video work.

Genre-Focused Performance: Which Camera Excels Where?

I’ve evaluated both cameras across a broad range of photography disciplines, considering the user demands of each field.

• Portraits: The K-5 IIs delivers accurate skin tones, superior bokeh potential (with fast primes), and eye-detection autofocus. The TG-810 is adequate for snapshots but lacks the selective AF and glass to create compelling portraits.

• Landscapes: With better dynamic range and resolution, plus weather sealing, the K-5 IIs is ideal for landscapes. TG-810’s rugged shell helps in challenging environments, but image quality limitations are evident in large prints.

• Wildlife: Fast autofocus, high burst rates, and telephoto lens options make the K-5 IIs compelling here. The TG-810’s fixed lens and slower AF limit wildlife use to casual observations.

• Sports: The K-5 IIs is purpose-built for action with high FPS and reliable focus tracking. The TG-810 cannot keep pace.

• Street: TG-810’s compact, discreet form factor wins for sneaky street shooting; the K-5 IIs is obtrusive but offers better image quality.

• Macro: The Pentax supports macro lenses and manual focus precision; TG-810 gets in close to 3cm but with less creative control.

• Night/Astro: Higher ISO capabilities and longer exposures on the K-5 IIs dominate this field.

• Video: K-5 IIs produces more professional video; TG-810 is limited.

• Travel: TG-810’s waterproof design is travel-friendly for adventure; K-5 IIs excels in versatility and quality but requires more gear.

• Professional: K-5 IIs is far more suited for professional use thanks to file formats (RAW), workflow integration, and robust controls.

Real-World Image Samples: Seeing is Believing

Let’s look at comparative photos taken with both cameras under identical conditions.

Olympus TG 810 front Olympus TG 810 screen back Pentax K 5 IIs front Pentax K 5 IIs screen back

Notice in the close-up portraits how the Pentax’s subject renders with finer detail and smoother background blur, while the Olympus images appear flatter, less refined. Landscape shots show the Pentax maintaining highlight retention and better shadow detail, whereas the Olympus clips appear more contrast-limited and noisy.

Overall Ratings and Value Assessment

Assigning scores based on technical testing, image quality, handling, and value, the K-5 IIs scores significantly higher, reflecting its advanced features and image superiority. The Olympus TG-810 scores well in toughness and ease of use but doesn’t compete in overall imaging.

In terms of price-to-performance, the TG-810’s sub-$450 price offers budget-friendly ruggedness that no DSLR can match. The K-5 IIs at approximately $750 is an excellent entry point for a professional-grade DSLR system but demands a lens investment for full potential.

Final Verdict: Who Should Pick Which?

This dog loves both cameras for what they set out to do. However, they cater to very distinct audiences.

Choose the Olympus TG-810 if you:

• Want an ultra-rugged compact camera for hiking, snorkeling, or casual adventure memories.
• Prioritize portability, waterproofing, and shake reduction over pro image quality.
• Shoot mostly in good light, favor snapshots, and dislike bulky gear.
• Need GPS tagging and basic video recording on the go.
• Are on a strict budget and want decent all-in-one simplicity.

Opt for the Pentax K-5 IIs if you:

• Demand the highest image quality within a mid-tier DSLR system.
• Need full manual control, plus fast, accurate autofocus.
• Shoot multiple genres - portraits, landscapes, wildlife, sports - with flexibility.
• Require RAW shooting for professional workflows.
• Value a rugged but more refined DSLR body with interchangeable lenses.
• Expect long battery life and advanced exposure options.

Wrapping it Up: A Tale of Two Cameras and Their Niches

The Olympus TG-810 is a rugged, no-nonsense compact camera tailored for those who want worry-free operation in rugged environments. It’s the ultimate adventure buddy when lugging heavy gear isn’t an option, but image quality and creative control take a back seat.

The Pentax K-5 IIs stands as a classic workhorse DSLR, marrying solid build and excellent image quality with professional-grade features. It remains a capable tool in the hands of enthusiasts and pros who appreciate the Pentax ecosystem and demand flexible, high-performing gear for diverse photography needs.

When you choose between these two, you’re really deciding between convenience and durability versus photographic versatility and quality. Both bring valid propositions; your choice depends on your shooting style, environment, and ambitions.

This comparison is based on extensive hands-on tests, lab measurements, and real-world shooting sessions. For more in-depth analyses or tailored advice, feel free to reach out or check our updated database of camera reviews.

Happy shooting!