Panasonic FX90 vs. Pentax K-S1: A Hands-On Comparison from My Experience

As someone who has spent over 15 years testing and comparing digital cameras across genres - from landscapes spanning across continents to fleeting moments in street photography - I’ve seen how diverse camera technology and design philosophies can be. Today, I’m diving into two very different cameras that might puzzle some buyers: the pocket-sized Panasonic Lumix DMC-FX90, a small sensor compact from 2011, and the mid-sized APS-C Pentax K-S1 DSLR from 2014. While they share the broad goal of capturing beautiful photos, their technical underpinnings, user experiences, and photographic strengths couldn’t be more distinct.

If you’re considering either camera, or simply curious how a compact point-and-shoot stacks against an entry-level DSLR, this article will unpack key differences, real-world performance, and who each camera truly benefits. Let’s jump in.

Size and Handling: Compact Convenience vs. DSLR Ergonomics

First impressions count, and handling these cameras side-by-side reveals their very different natures. The Panasonic FX90 is incredibly pocket-friendly, measuring 102 x 56 x 22 mm and weighing just 149 grams. It's easy to sweep into a jacket pocket or handbag - ideal for quick grabs or travel when minimalism is key.

In contrast, the Pentax K-S1 tips the scales at 558 grams, with dimensions of 121 x 93 x 70 mm. It demands more space in your bag and needs a deliberate hand to wield, but its DSLR design provides robust grip and superior button placement for quick manual controls.

When I tested the FX90 during a day-long city stroll, I appreciated not having to think about carrying a bulky rig. However, when shooting more methodically in the studio or on location, the K-S1’s hefty grip and shooter-focused layout made a huge difference for stability and comfort.

The top control layout also reflects this divide:

The FX90 adopts a minimalist approach - one-lens zoom, basic shutter and mode dials, and a touchscreen interface. If you’re new to photography or looking for a casual companion camera, this keeps things direct - and yes, that touchscreen responsiveness impressed me compared to other compacts of its era.

Meanwhile, the K-S1 features a traditional DSLR top plate with a mode dial, ISO, exposure compensation, and dedicated shutter speed/aperture controls. I found this enables faster, more intuitive adjustments when working on shoots requiring exposure precision.

Bottom line: For those prioritizing portability and ease, the FX90 excels; photographers craving manual control and ergonomic stability will gravitate towards the K-S1.

Sensor Size and Image Quality: The Heart of the Matter

Now, let’s talk about the cameras’ image sensors, the engine for picture quality.

The Panasonic FX90 employs a 1/2.3-inch CCD sensor sized about 6.08 x 4.56 mm, with 12 megapixels of resolution. In contrast, the Pentax K-S1 sports a much larger APS-C CMOS sensor measuring 23.5 x 15.6 mm and packing 20 megapixels.

To put this in practical terms:

• The FX90's sensor area is 27.7 mm²
• The K-S1's sensor area is 366.6 mm² (more than 13 times larger!)

What does this mean for you? Larger sensors typically provide:

• Better image quality especially in low light due to bigger pixel size
• Greater dynamic range for capturing both dark shadows and bright highlights
• More control over depth of field, enabling creamy bokeh portraits

During my hands-on sessions, the K-S1’s larger sensor translated into noticeably cleaner images at ISO 1600 and above, whereas the FX90 images exhibited visible noise starting from ISO 400. The K-S1 also showed impressive dynamic range preserving subtle shadow details in landscapes.

The FX90’s CCD sensor, while dated and limited in scope, still delivered respectable daylight shots with decent color rendition. It’s a classic example of a compact camera serving casual shooters well, but it’s important to set expectations accordingly.

On resolution, the K-S1’s 20MP files produce high-detail prints and cropping flexibility. The FX90’s 12MP output is fine for web use and small prints, but falls short of professional productivity.

The View and Interface: How You Compose and Review Images

Neither camera offers a built-in electronic viewfinder in a modern sense, though the K-S1 compensates with its optical pentaprism viewfinder - offering a 100% coverage and 0.64x magnification. For action or precise framing, this is invaluable.

The FX90 lacks any viewfinder, relying solely on a fixed 3-inch, 460k-dot touchscreen TFT LCD.

While the FX90’s touchscreen is responsive and enables quick focusing/tapping, its brightness and resolution limitations became apparent in bright sunlight conditions. The K-S1 offers a sharper 3-inch 921k-dot LCD but no touch capability - a trade-off you should weigh depending on your preference.

For me, the optical viewfinder on the K-S1 was crucial for outdoor work, particularly in sports and wildlife where quick sighting beats LCD lag or sun glare. However, for casual travel snaps or street portraits, the FX90's touchscreen helped speed up focusing and framing.

Autofocus Systems: Speed and Accuracy Throwdown

Autofocus can make or break a camera’s usability in dynamic shooting conditions. Let’s see how these two cameras compare.

• Panasonic FX90: Contrast detection AF, 23 focus points, no face detection, but touch AF support.
• Pentax K-S1: Hybrid AF combining phase-detection and contrast-detection, 11 focus points with face detection.

I put these systems through their paces in varied scenarios, from portraiture to wildlife.

With the FX90, focusing was reliable in good light but noticeably slower and prone to hunting in dim or low-contrast scenes. Its lack of face detection means portraits rely on subjective focus placement - a slight handicap for beginners or casual users.

The K-S1’s phase-detection system offers fast, accurate autofocus with tracking modes that held moving birds and runners sharply in focus. The camera’s face detection helped lock onto subjects in portrait sessions, significantly improving keeper rates.

Continuous autofocus during burst shooting further amplified the K-S1’s edge - at 5.4fps compared to the FX90’s 4fps (still respectable for a compact).

Lens and Focal Length Range: Flexibility in Framing

Another fundamental difference is the lens system:

• FX90: Fixed 24-120mm (equiv.) zoom lens with modest f/2.5-5.9 aperture.
• K-S1: Interchangeable lens system (Pentax KAF2 mount), compatible with over 150 lenses.

The FX90’s lens covers a useful range equivalent to a 5x zoom - handy for travel and casual use. Image stabilization is optical, helping keep shots steady. Macro mode allows focusing as close as 3cm, a fun feature for close-ups.

However, it lacks specialized lenses or aperture control, limiting artistic breadth.

Meanwhile, the K-S1’s versatility is impressive - you can mount everything from fast primes for portraits, super-telephoto lenses ideal for wildlife, to macro optics for details. Additionally, the K-S1 benefits from sensor-based stabilization, working even with legacy lenses.

This flexibility means the K-S1 can adapt to technique-driven photographers who want to experiment or genre-hop with their gear.

Photo Quality Across Genres: Real-World Use Cases Compared

Portraits and Skin Tones

The K-S1’s larger sensor and lack of anti-aliasing filter produce crisp, detailed skin textures and pleasing bokeh effects, crucial for portraits. Its face detection AF bolstered focus accuracy on eyes, while manual controls enabled refined exposure shaping.

The FX90 delivers smooth, natural skin tones but can’t match background separation or shallow depth of field. The lack of face detection means you have to trust autofocus area selection, which sometimes missed the mark.

Landscapes and Dynamic Range

Thanks to the APS-C sensor, the K-S1’s dynamic range shines in high-contrast scenes. I captured dawn and dusk landscapes revealing rich shadow detail and highlight preservation. The DSLR’s weather sealing and sturdy build, although not comprehensive, better suit outdoor environments than the FX90.

The FX90’s smaller sensor and higher noise at low ISOs limit landscape impact, but it easily fits in a jacket pocket on spontaneous hikes.

Wildlife and Sports

The K-S1’s speedy phase-detection AF, higher burst rate, and longer telephoto lenses make it a clear winner. Tracking fast animals or athletes was smooth and reliable in my testing.

The FX90’s slower contrast AF and limited zoom make it less suited to these disciplines.

Street Photography

While the K-S1 can deliver quality images here, its bulk impairs discretion. The FX90’s compact size and quiet operation are ideal for candid street shots.

Both cameras cope decently with low light, but the K-S1 lets you push ISO higher with less noise.

Macro

The FX90’s 3cm macro focus distance enables decent close-ups on the fly. The K-S1, with dedicated macro lenses and stabilization, shoots razor-sharp close-ups with more precision and creative control.

Night and Astro

High ISO performance clearly favors the K-S1, allowing longer exposures with reduced noise. The FX90 is practical only for casual night scenes under street lights.

Video Performance: Capabilities and Limitations

Both cameras offer Full HD video recording:

• FX90: 1920x1080 at 60fps, plus lower resolutions. No external mic input.
• K-S1: 1920x1080 up to 30fps, with H.264 compression. Also lacks mic input.

I found video on the FX90 smoother due to 60fps recording, great for casual clips. The K-S1’s video, while limited to 30fps, benefits from larger sensor depth and interchangeable lenses - offering cinematic flexibility.

Neither camera features 4K video or microphone input, limiting professional-level video work.

Connectivity, Storage, and Battery Life

Both cameras support SD/SDHC/SDXC cards and have HDMI/USB 2.0 ports. The FX90 includes built-in wireless (Wi-Fi), helpful for quick sharing, whereas the K-S1 supports Eye-Fi card connectivity but no Bluetooth or NFC.

Battery life dramatically favors the K-S1 at 410 shots per charge, compared to the FX90’s 200 shots (likely due to the power demands of the DSLR’s larger sensor and viewfinder).

Given this, the K-S1 is better suited for travel or multi-hour shooting sessions without frequent battery swaps.

Durability and Build Quality

Neither camera is weather sealed or ruggedized, but the solid construction of the K-S1 DSLR gives a perception of better durability. The FX90’s plastic compact body feels less robust, though it survived my field tests with standard care.

Price and Value Discussion

At time of writing, the FX90’s street price is around $227, while the K-S1 is approximately $339. The price difference reflects their respective technologies and target users.

If budget is your primary concern, and you desire a straightforward camera for casual use, the FX90 is a smart value. However, for serious image quality, manual control, and future-proofing with lenses, the K-S1 offers more bang for the buck despite the heft.

Visual Evidence: Sample Photos in Various Conditions

Panasonic FX90 front Panasonic FX90 screen back Pentax K S1 front Pentax K S1 screen back

Looking closely at these side-by-side samples I took - portraits, landscapes, macro shots - you can see the K-S1’s superior sharpness, color depth, and dynamic range stand out, especially in challenging light.

Quantitative Performance Scores

To round out this detailed comparison, here are the overall and genre-specific performance ratings I compiled based on lab tests and real-world shooting:

Who Should Buy Which Camera?

After extensive hands-on testing, here’s my bottom line for you:

• Choose the Panasonic FX90 if:

  • You want a compact, lightweight camera for casual travel, street photography, or family snapshots.
  • You prioritize portability and ease over ultimate image quality.
  • Your budget is tight but you want reliable autofocus and simple video.
  • Post-processing is minimal and RAW shooting is not essential (FX90 does not support RAW).

• Choose the Pentax K-S1 if:

  • You want DSLR image quality with large APS-C sensor performance.
  • You desire manual control and expandable lens options.
  • You shoot portraits, landscapes, wildlife, or sports and need fast autofocus and burst rates.
  • You will benefit from longer battery life and better low-light performance.
  • RAW format support and workflow integration are important to your post-processing.

Final Thoughts: Cameras Tailored to Different Needs

The Panasonic Lumix FX90 and Pentax K-S1 represent two points on the photographic spectrum. The FX90 is a friendly, pocket-sized traveler’s companion best suited for spontaneous, casual photography without fuss. Meanwhile, the K-S1 challenges you to engage more deeply with photographic craft, delivering significantly better image control, quality, and versatility.

My personal experience underscores the value of understanding your priorities and shooting style before investing. Neither camera is perfect, but both have clear strengths for different photographers.

As always, I encourage readers to hold, test, and shoot with cameras when possible - images and specs only tell part of the story. And if you’re contemplating one of these models, you’ll find many years of photographic satisfaction if matched well to your creative vision.

Happy shooting!

Disclosure: I received neither product nor compensation from Panasonic or Pentax for this review. All testing and opinions are from my independent, professional evaluation.