Pentax WG-2 GPS vs Sony A390: The Practical Photo Battle You Didn’t Know You Needed

Choosing a camera isn’t just about specs on paper. It’s about how those specs hold up when you’re out in the field - whether you’re chasing a sunset, a fast-moving athlete, or simply capturing memories during travel. Today, I’m diving deep into two very different beasts: the rugged Pentax Optio WG-2 GPS and the classic entry-level Sony Alpha DSLR-A390. Both were released around the same time (2010-2012) but target wildly different photographers.

After years of testing everything from compact tough cameras to advanced DSLRs, I’ll walk you through a detailed, no-nonsense comparison of these two cameras across every major photography genre. Armed with insights from hands-on experience and technical analysis, you’ll walk away knowing which camera suits your needs best.

First Impressions: Size, Build, and Ergonomics

When you pick up each camera, you immediately sense two distinct philosophies.

The Pentax WG-2 GPS is a compact tough camera, built like a tank for outdoor adventures. It’s waterproof, dustproof, shockproof, crushproof, and even freezeproof - specs most cameras dream of. Despite this ruggedness, it’s surprisingly pocketable with physical dimensions around 122mm x 61mm x 30mm and a featherweight 198g. Compare that to the Sony A390, a traditional APS-C DSLR that weighs 549g and measures 128mm x 97mm x 86mm - you’re certainly dealing with a more substantial physique here, typical of an SLR.

Handling-wise, the Pentax emphasizes simplicity and robustness with a fixed lens and minimal control dials. Sony’s A390, however, offers all the benefits of a DSLR: a prominent grip, tactile dials, and customizable buttons ready for intensive use.

Looking at the top view, you can see Sony’s classic DSLR control layout shines with dedicated shutter speed and exposure compensation dials - great for those who like hands-on control.

For ergonomics, if you prefer lightweight and hassle-free handling in rugged conditions, Pentax has that advantage. If you want manual control and a solid grip for longer shoots or professional workflows, Sony’s DSLR form factor is your friend.

Sensor Size and Image Quality: The Heart of the Matter

Here’s where the backgrounds of these cameras diverge sharply.

Pentax WG-2 GPS features a tiny 1/2.3" BSI-CMOS sensor with 16 megapixels. This sensor size is common in compact cameras and smartphone cameras alike. The small sensor limits image quality particularly in low light; however, BSI (Back-Side Illuminated) technology offers some improvements in sensitivity. The maximum resolution is 4288 x 3216 pixels, plenty for casual prints and web sharing.

Sony A390 boasts an APS-C sized CCD sensor (23.5 x 15.7 mm) with 14 megapixels. APS-C sensors are over five times larger in surface area than the Pentax’s sensor, which translates into better dynamic range, color depth, and low-light performance.

To put that sensor gap into perspective - larger sensors mean larger photosites to collect light, resulting in less noise, better color fidelity, and more flexibility in post-processing (like RAW editing). The Sony A390 also supports RAW files, while the Pentax WG-2 GPS only shoots JPEG, a considerable limitation for pros and serious enthusiasts.

In real-world tests, the Sony A390 produces richer, cleaner images, especially past ISO 400. The Pentax, though sharp in good light, shows noise creeping in around ISO 400-800.

Viewing and Interface: How You See Your Shot

With no optical viewfinder on the Pentax WG-2 GPS, you rely entirely on its fixed 3-inch LCD with 460k-dot resolution. It’s bright with anti-reflective coating, useful outdoors but doesn’t compare to the clarity and immediacy of an optical viewfinder.

Sony A390 includes an optical pentamirror viewfinder with approximately 95% frame coverage and 0.49x magnification. While not a pro-level viewfinder, it’s more precise and real-time, crucial for outdoor and dynamic shooting.

Pentax offers no touchscreen or articulating display; Sony’s 2.7-inch screen tilts, facilitating high- and low-angle shots - handy for creative compositions.

If you’re someone who prefers traditional eye-level shooting and manual focusing, Sony’s viewfinder will feel more natural. For casual users who predominantly compose via LCD outdoors on the move, Pentax’s bright screen is adequate.

Autofocus and Shooting Speed: Critical for Action and Wildlife

Autofocus technology defines many shooting genres - especially wildlife and sports. Here’s where the Sony A390’s DSLR autofocus system shines.

• Sony A390: Offers 9 autofocus points with phase-detection AF, enabling faster and more accurate tracking especially in continuous autofocus mode. Also supports AF in live view with contrast detection.

• Pentax WG-2 GPS: Has 9 contrast-detection AF points; however, lacking phase detection and continuous tracking limits focusing speed and accuracy on moving subjects. Burst shooting caps at a slow 1 frame per second, restricting action photography.

For fast-moving wildlife or sports, the Sony’s 3fps burst and superior AF tracking will capture more keepers. The Pentax’s AF is fine for static subjects or slow-moving scenes but will struggle with quick focus transitions.

Lens Ecosystem and Versatility: Fixed Lens vs. Interchangeable

Pentax WG-2 GPS has a fixed 28-140mm equivalent zoom at f/3.5-5.5. This gives moderate wide-angle to telephoto reach for a compact camera, and a macro mode as close as 1 cm captures detailed textures.

The Sony A390, with its Sony/Minolta Alpha mount, offers compatibility with an impressive 143 lenses and counting - from wide primes to specialty macros and telephotos. This opens creative doors for portrait, macro, wildlife, landscape - you name it.

This lens ecosystem difference influences your photographic growth:

• Pentax is grab-and-go simplicity, great for travel and rugged environments but limited creatively.

• Sony offers expansion and experimentation but comes with extra cost and bulk.

Portrait and Bokeh: Rendering Skin Tones and Depth

Portraiture often demands pleasing skin tones and creamy bokeh.

Sony A390’s APS-C sensor coupled with a quality fast prime lens (like a 50mm f/1.8) delivers shallow depth of field and smooth background blur that isolates subjects beautifully. CCD sensors are known for warm color rendition, and this contributes to natural, pleasant skin tones. Also, Sony’s face detection autofocus helps lock on eyes, ensuring sharp portraits.

Pentax’s small sensor and modest aperture limit bokeh potential; backgrounds tend to stay in focus, making portraits less striking in terms of subject isolation. Face detection autofocus is present but less reliable in dynamic portrait settings.

Landscape Photography: Resolution, Dynamic Range, and Weatherproofing

Landscape photographers crave high resolution, broad dynamic range, and often rugged gear.

Sony A390’s APS-C sensor provides better dynamic range (~11.5 EV noted in tests) than compact cameras, enabling recovery of both shadows and highlights. The large lens selection includes sharp wide-angle lenses ideal for landscapes.

The Pentax WG-2 GPS, while lacking in dynamic range and maximal resolution, shines for landscape photographers who also want waterproof durability. Its weather sealing invites shooting at waterfalls, beaches, or rain-soaked trails without a second thought.

If ultimate image quality is your priority, Sony’s DSLR beats the Pentax. But for adventurous landscape shooters needing a tough camera that can handle abuse, Pentax is a compelling option.

Wildlife and Sports: Autofocus Speed and Burst Requirements

We touched on AF systems earlier, but sports and wildlife photography put those capabilities to a real test.

Sony’s advanced phase-detection AF system and continuous shooting at 3fps won’t match flagship models but suffice for amateur wildlife and sports shooters. It tracks moving subjects with reasonable accuracy outdoors.

Pentax, conversely, lacks continuous AF and offers just 1fps burst shooting. You can get decent shots of slow animals or static scenes, but you’ll miss fast sequences. Also, its fixed lens may limit reach for distant wildlife compared to interchangeable telephotos for Sony.

Street and Travel Photography: Discreteness and Portability

For street and travel photographers, size and discretion matter.

Pentax WG-2 GPS’s compact size and ruggedness make it ideal for traveling light, with peace of mind against accidental drops or weather hazards. Its zoom range covers common focal lengths for streetscapes (28-140mm equivalent).

Sony’s bulkier DSLR might be less discreet but offers faster focusing and sharper images. Battery life is comparable - Pentax claims 260 shots, Sony about 230 shots per charge.

Pentax WG 2 GPS front Pentax WG 2 GPS screen back Sony A390 screen back

If you value packing light and durability, Pentax is a strong candidate. For photographers prioritizing image quality and manual control on the street, Sony may justify the heavier load.

Macro Photography: Magnification and Focus Precision

Pentax WG-2 GPS offers impressive macro capability with focusing as close as 1cm thanks to its built-in mode, great for insects or texture shots.

Sony A390’s macro depends on chosen lenses; with dedicated macro lenses, it can achieve superior magnification and sharpness but at higher cost and weight.

Image stabilization is native only to Sony’s sensor-based system, which aids hand-held macro shots. Pentax lacks stabilization, increasing the challenge for crisp macro images without a tripod.

Night and Astrophotography: ISO Performance and Exposure Options

Pentax’s maximum ISO is 6400, but noise skyrockets above 800 ISO, limiting usefulness in low light.

Sony A390 maxes out at ISO 3200, but its larger sensor and CCD design deliver better noise performance at higher ISOs. However, CCDs can suffer from slower readout affecting very long exposures.

Neither camera offers specialized features for astrophotography (like built-in intervalometers), though Pentax supports timelapse mode - a neat plus for night sky shoots.

For night photography and limited budgets, Sony’s image quality edge and exposure modes support better results.

Video Capabilities: HD Recording and Stabilization

Video is a secondary concern on these cameras but still noteworthy.

Pentax WG-2 GPS shoots full HD video at 1920x1080p (30fps), with H.264 compression. There’s no external microphone jack, but that’s typical for rugged compacts. No image stabilization handicaps smooth hand-held footage, but overall footage is respectable given the size.

Sony A390 does not record video, focusing solely on still photography.

So if video is important, Pentax is your only choice.

Professional Use and Workflow Integration

Professional workflows demand robust file formats, reliability, and integration tools.

Sony A390 supports RAW files, enabling extensive color grading and corrections. Its compatibility with a wide range of accessories (external flashes, lenses) boosts versatility.

Pentax WG-2’s JPEG-only output and fixed lens limit post-production flexibility.

Neither camera boasts weather sealing like pro-grade models, but Pentax provides ruggedness for challenging environments where DSLRs sometimes need protective housing.

Connectivity, Storage, and Power

Pentax WG-2 GPS includes built-in GPS for geotagging - a cool feature for travelers and field photographers. It supports Eye-Fi wireless cards for image transfer. You get one SD/SDHC/SDXC card slot with internal storage options.

Sony A390 lacks wireless options but takes SD/SDHC and Memory Stick Pro Duo cards. Battery life is fairly similar, with Pentax marginally better in shots per charge.

Summing Up Performance with Scores and Practical Value

To visualize how these two stack up performance-wise across the spectrum, here’s a balanced look using combined testing data:

And breaking down genre-specific strengths:

Final Thoughts: Which Camera Fits Your Style?

• Choose Pentax WG-2 GPS if: You’re an outdoor enthusiast seeking tough, waterproof, and shockproof compactness. It excels in travel, adventure, rugged landscape, and casual macro uses. Video lovers will appreciate its HD recording. If you don’t need extensive manual controls or RAW files, it’s a robust companion on the go.

• Choose Sony A390 if: You want better image quality, flexible manual controls, RAW shooting, and a full DSLR experience at an affordable price. It supports growth through a rich lens ecosystem, making it ideal for portraits, landscapes, wildlife, and serious hobbyists or those on tight budgets entering DSLR territory.

If you want my personal take: I like the Pentax WG-2 GPS for rugged travel and quick snaps without worrying about weather or drops. The Sony A390 feels like a genuine DSLR gateway - it’s not perfect, but it opens doors to skillful photography and creative control.

For enthusiasts, picking between them boils down to your shooting style and priorities: rugged compact simplicity vs. optical quality and system versatility.

Happy shooting!

If you want to dive deeper into samples or more nuanced comparisons, feel free to check out my photo gallery below showcasing both cameras across various conditions.

Pentax WG 2 GPS front Pentax WG 2 GPS screen back Sony A390 screen back