Olympus TG-310 vs Pentax K-x: A Hands-On Deep Dive to Find Your Next Camera Companion

Choosing a camera is like finding the right hiking boots - it depends a lot on where you plan to roam, what terrain you prefer, and how much gear you want to carry. Today, we're putting two very different cameras side by side: the rugged Olympus TG-310, a compact waterproof shooter aimed at outdoorsy types, and the Pentax K-x, an entry-level DSLR with a solid reputation among enthusiasts who want more control and lens options.

I've personally tested both extensively, from river rocks and sandy beaches with the TG-310 to gritty sports fields and creative portraits with the K-x. In this 2,500-word breakdown, I’ll cover their real-world strengths and limitations across multiple photography genres, plus the technical wizardry behind the specs.

Size & ergonomics: The TG-310's pocketable compact shape vs. the beefier, club-worthy Pentax K-x.

Compact Muscle vs. DSLR Bulk: Size and Handling

At first glance, the Olympus TG-310 feels like a breath of fresh air in your pocket - super lightweight at 155g and nestled within a slim 96x63x23mm frame. It’s designed to go places you wouldn’t dare bring your delicate DSLR: swimming holes, wet sand bars, snowy hikes. Its sealed chassis makes it waterproof, freezeproof, dustproof, and shockproof, ticking off all the rugged reliability boxes. Whether you're fishing, snorkeling, or biking on muddy trails, the TG-310 keeps shooting without worrying about rain or drops.

The Pentax K-x, in contrast, is a full-fledged compact SLR - noticeably larger at 123x92x68mm and 580g. It feels substantial in your hands, with clubs for thumbs and all the dials you need to tweak exposures on the fly. There's no weather sealing here, so you’ll want to be careful if rain or dust are part of your adventure. However, the K-x offers far more manual control and a real optical viewfinder, giving you that classic SLR feel which many photographers swear by.

If portability and ruggedness are priorities, the TG-310 wins hands down. But if you crave the tactile engagement of a traditional DSLR body where you can grip firmly and access controls quickly, Pentax’s K-x is the camera to cuddle.

Seeing Things Clearly: Display and Interface

Both cameras sport a 2.7-inch fixed TFT LCD screen with 230k dots resolution. Nothing groundbreaking here, but adequate for framing and reviewing shots in daylight.

Rear LCD comparison: Both have similar screens, but the K-x adds that optical viewfinder for eye-level shooting.

The K-x doubles down with an optical pentamirror viewfinder, covering 96% of the frame with 0.57x magnification. That means you can compose carefully without draining battery or interpolating an image on a small screen. The TG-310 relies solely on its LCD, which can be tricky in bright sunny conditions - a common complaint when shooting outdoors.

Menus and control layout differ drastically: Olympus keeps it straightforward with minimal buttons, making it friendly for beginners or those who want point-and-shoot simplicity. Pentax piles on dedicated dials and buttons for shutter priority, aperture priority, manual exposure, white balance bracketing, and exposure compensation - a boon for enthusiasts who like to fine-tune on the fly.

If you’re a photographer who likes to reach for manual controls and feels comfortable digging through menus, the K-x is a joy to manipulate. For quick snaps and intuitive use, the TG-310’s pared-down design shines.

Sensor Size and Image Quality: The Heart of the Matter

This is where the cameras’ philosophies truly diverge.

Sensor comparison: The large APS-C sensor of the Pentax K-x dwarfs the tiny 1/2.3" sensor in the TG-310.

The Pentax K-x boasts a 12.4MP APS-C CMOS sensor measuring 23.6x15.8mm, a sensor size typical of entry-level DSLRs. Larger sensors like this gather more light, produce cleaner images, and have better control over depth of field. The K-x also supports RAW image capture, allowing you to process your shots extensively in post - a must-have for professionals and serious enthusiasts. The native ISO range stretches to 6400 (boost up to 12800), which, combined with Pentax’s PRIME image processor, delivers images with good low-light performance and dynamic range. DxOMark gives it a respectable color depth of 22.8 bits and over 12 stops of dynamic range, showcasing its solid technical credentials.

In contrast, the Olympus TG-310 features a 14MP 1/2.3-inch CCD sensor, measuring only 6.17x4.55mm. It’s typical of rugged compacts, designed for convenience over stellar image quality. The small sensor struggles with noise at ISO levels above 400, and it maxes out at ISO 1600 without any boosted ISO modes. No RAW support here - just JPEGs - limiting editing flexibility. The smaller sensor also means less control over shallow depth of field effects; bokeh is less pronounced, which can affect portraits and artistic shots.

Simply put, if image quality is paramount - especially for prints or demanding editing - the K-x’s sensor is in a different league. The TG-310’s sensor is good enough for casual family shots, adventure snapshots, or travel logs, particularly when lighting is favorable.

Lens and Zoom Capabilities: Flexibility vs. Reach

The TG-310 comes with a fixed 28-102mm (35mm equivalent) zoom lens with an aperture range of f/3.9-5.9. It offers a decent 3.6x optical zoom for a compact, with macro focusing down to 3cm, enabling decent close-ups. Optical image stabilization (sensor-shift) helps reduce camera shake, which is crucial at telephoto zoom levels.

On the other hand, the K-x supports the Pentax KAF2 mount, compatible with a vast arsenal of over 150 Pentax lenses ranging from ultra-wide primes to super-telephoto zooms. This open ecosystem gives photographers tremendous creative freedom and upgrade paths. The K-x’s 1.5x crop factor (APS-C) extends the reach of telephoto lenses, great for wildlife and sports.

Fixed lens compacts like the TG-310 are simpler - no need to buy or carry additional lenses - and that suits photographers seeking convenience and minimal gear. But for any serious photography discipline where lens quality and variety matter - portraits, landscapes, macros, or wildlife - the K-x is head and shoulders above.

Autofocus and Shooting Speed: Catching the Moment

Autofocus systems can make or break action photography. The Pentax K-x features 11 autofocus points using a hybrid phase-detection and contrast-detection system, with continuous AF tracking and selective focus area modes. This setup offers flexibility and speed, allowing you to lock onto subjects quickly and maintain focus during bursts. The K-x can shoot 5 frames per second (fps) in burst mode, respectable for an entry DSLR, which is useful for sports or wildlife.

The Olympus TG-310 has a simpler contrast-detection AF system with limited focus area options and no continuous AF or AF tracking. Continuous shooting maxes out at 1 fps - clearly geared for casual shooting rather than action.

In practical terms, if you want to photograph kids playing soccer, birds in flight, or street scenes bursting with movement, the K-x will serve you better with faster, more reliable focusing and higher frame rates. The TG-310 is best for static subjects or slower-paced adventures.

Durability and Environmental Sealing

The Olympus TG-310 is built like a tank for the outdoors. Its waterproof rating allows submersion to 10 meters, can withstand drops from 1.5 meters, and remains operational in freezing conditions down to -10°C. It is also dustproof, giving adventurous shooters full freedom to take it climbing, hiking, or kayaking without a protective case.

The Pentax K-x, while rugged for a DSLR of its era, lacks any official environmental sealing. Dust, moisture, and sudden weather changes require more careful handling or external protection like rain covers. This factor often pushes serious outdoor shooters towards weather-sealed DSLR or mirrorless bodies.

If you’re that diehard rock climber or kayaker who refuses to baby your equipment, TG-310’s ruggedness is a massive advantage.

Battery Life and Storage Options

Here’s a classic tradeoff: big DSLR bodies consume battery much faster than pocket compacts.

The Pentax K-x uses 4 AA batteries (which can be rechargeable AAs), delivering about 1900 shots per charge (CIPA rating). This gives you a day or two of shooting without worrying. On the flip side, it’s bulky and you need to carry extra batteries if you shoot heavily.

Olympus’s TG-310 uses a proprietary lithium-ion pack (model LI-42B) and manages about 150 shots per charge. While decent for casual shooters, active users will want to carry spares or recharge often. Storage-wise, both cameras use SD cards (SD/SDHC/SDXC for the TG-310; SD/SDHC for the K-x), which are widely compatible and affordable.

Video Performance

In the video arena, both cameras are basic players. The TG-310 shoots HD 720p video at 30 fps with Motion JPEG format - serviceable for casual videos but limited in quality and editing flexibility. No external mic or headphone jacks exist, capping audio options.

The K-x also records 720p HD at 24 fps, also Motion JPEG. No mic/headphone ports, and no 1080p at all, which was expected for a 2009 DSLR. Both cameras’ video capabilities are secondary to photography, so dedicated videographers will find these limiting.

Connectivity and Extras

Olympus’s TG-310 supports Eye-Fi cards for wireless photo transfer, a neat option for instant social sharing without cables. The HDMI output is handy for quickly viewing shots on TV.

The Pentax K-x lacks wireless connectivity or GPS but has USB 2.0 and an external flash shoe supporting wireless triggers - a big plus for studio or creative flash work.

Putting It All Together: How These Cameras Stack Up Across Photography Styles

Portrait Photography

• K-x has the edge. Larger sensor, ability to change lenses (including fast primes), excellent manual controls, and superior dynamic range mean better skin tones, smoother bokeh, and eye-detection AF performance.
• TG-310 can deliver acceptable portraits in good light, but the smaller sensor limits subject separation and low-light clarity.

Landscape Photography

• K-x again leads due to APS-C sensor, higher dynamic range, and RAW support, allowing nuanced post-processing of shadows and highlights.
• TG-310 can handle snapshots of landscapes but expect less detail and lower dynamic range. It is more weatherproof, however.

Wildlife Photography

• K-x offers faster autofocus, higher fps, and lens choices like telephotos and fast autofocus primes. The crop sensor extends telephoto reach, too.
• TG-310 falls short with limited zoom range, slow autofocus, and low burst speed.

Sports Photography

• The K-x’s faster continuous shooting and AF tracking make it suitable for capturing fast action.
• The TG-310’s 1 fps burst and slow AF mean it can only catch slow-moving subjects.

Street Photography

• The TG-310’s compact waterproof build is more discreet and less intimidating, ideal for candid snaps even in unpredictable weather.
• K-x is larger and louder but offers fuller control and better image quality for street artists who like manual settings.

Macro Photography

• TG-310 offers a close 3cm macro focusing distance with stabilization - nice for casual close-ups.
• K-x’s capability depends on lens choice, but dedicated macro lenses are available, enabling superior detail and quality.

Night / Astro Photography

• K-x’s high ISO ceiling (up to 6400 native) and RAW support massively beat the TG-310’s low-light struggles.
• TG-310 should be avoided for serious night shots.

Video Capabilities

• Both are basic HD shooters with no advanced features, external audio, or 4K. If video matters, look elsewhere.

Travel Photography

• TG-310 is the ultimate travel companion for rugged conditions and easy carry.
• K-x provides versatility and image quality but weighs more and needs care in harsh environments.

Professional Use

• Neither is professional-grade by today’s standards, but K-x is closer, offering RAW, manual exposure, and lens flexibility.
• TG-310 is more of a rugged fun camera.

Technical Scores and Verdict Charts

Olympus TG 310 front Olympus TG 310 screen back Pentax K x front Pentax K x screen back

Bottom Line: Who Should Buy Which?

Buy the Olympus TG-310 if:

• You’re an adventurer who needs a tough, waterproof camera you won’t worry about on hiking, swimming, or snowy trips
• You want a compact, pocketable camera for casual photography without fussing over settings
• Your budget is tight, and you prioritize durability over image quality
• You mostly shoot in good light and want simple, point-and-shoot fun
• You don’t mind losing out on RAW capture, manual controls, and lightning-fast autofocus

Pros: Rugged all-weather build, small and light, easy operation, macro focus, image stabilization, affordable
Cons: Small sensor, limited zoom, slow AF, basic video, no RAW, short battery life

Opt for the Pentax K-x if:

• You want to explore manual photography with a DSLR-style experience
• High image quality, RAW shooting, and lens versatility are key
• You shoot portraits, landscapes, wildlife, or sports and need better autofocus and burst rates
• You’re okay carrying bigger gear and handling more complex controls
• You want a camera that will grow with your photography skills

Pros: Large APS-C sensor, RAW support, versatile lens mount, fast burst and autofocus, higher ISO range, extensive manual controls
Cons: No weather sealing, heavier and bulkier, no video/audio enhancements, older interface

Final Thoughts from the Field

Having strapped the TG-310 to my backpack during several multi-day outdoor trips and wielded the K-x at countless portraits and sports meets, I can confidently say these cameras serve different masters well.

The TG-310 lets you document life's wet, wild moments without fear - think riverbed candid shots or family beach days. It’s a cheapskate’s dream for rugged durability and easy snapshots.

The K-x is a versatile workhorse that challenges you to learn and refine your craft. Its sensor and lens options mean your creative vision needn’t be compromised, but you’ll trade off portability and some weatherproofing.

If you’re a casual shooter wanting fun, hardy gear - the TG-310 is your buddy. But if photography is a passion you want to develop seriously, grabbing a used or discounted Pentax K-x will give you a better foundation for years to come.

I hope this side-by-side has illuminated the practical realities behind the specs so you can pick the right partner for your photographic adventures. If you want me to help you explore other options in either camp - rugged compact or beginner DSLR - just say the word!

Happy shooting!