Comparing the Panasonic Lumix GX9 and Pentax Optio E90: Which Camera Serves You Best?

In my fifteen-plus years as a camera reviewer and photographer, few things have fascinated me as much as how vastly different cameras can be - even those that seem to compete in overlapping market spaces. Today, I’ll dive deep into a comparison between two very different models from two respectable brands: the Panasonic Lumix DC-GX9, an advanced mirrorless Micro Four Thirds camera announced in 2018, and the Pentax Optio E90, a compact fixed-lens point-and-shoot from 2010.

This head-to-head is not your typical "new vs. old" shootout. It’s more of a practical exploration of how a modern, fairly advanced mirrorless camera stacks against a small-sensor compact for a range of photography uses. I’ll lean heavily on my hands-on experience and extensive testing to guide you through sensor tech, ergonomics, autofocus, and real-world performance across photographic genres. By the end, I’ll synthesize what kind of shooter benefits most from each - and when to lean towards one or the other.

Let’s start with the basics.

First Impressions: Size, Handling, and Body Design

When I first held both cameras side-by-side, the noticeable difference in size and weight was immediately striking. The Panasonic GX9 feels substantially more robust and substantial, whereas the Pentax E90 is pocket-friendly and super light.

The GX9’s rangefinder-style mirrorless body measures 124mm wide by 72mm tall by 47mm deep and weighs 407 grams with battery - decently compact for a Micro Four Thirds camera but still designed for serious photo work. Contrast this with the E90’s tiny compact form factor (102 x 59 x 25 mm) tipping the scales at just 145 grams. This difference reflects the intended use cases entirely: the GX9 for advanced amateurs or pros wanting manual control and interchangeable lenses; the E90 as a grab-and-go simple camera.

The Panasonic’s magnesium alloy chassis offers a solid grip with its textured surfaces, a hitch-free tilt touchscreen, and dual dials for intuitive exposure adjustments. The Pentax insists on minimalism: no touchscreen here, a fixed lens, and plastic construction that feels toy-like next to the GX9’s heft but does the job for casual shooting.

Looking down from the top, the GX9 sports a detailed control layout with dedicated dials and buttons - ideal for photographers who prefer manual controls without diving into menus. The E90, however, is basic with a few top buttons and a control ring, making it a simple point-and-shoot, great for quick snaps without fuss.

The Heart of the Matter: Sensor and Image Quality

This is where the GX9 flexes its muscles. It deploys a Four Thirds sensor sized 17.3 x 13 mm, delivering 20 megapixels with no anti-aliasing filter - one of my favorite features as it sharpens detail resolution. Meanwhile, the Pentax E90 relies on an undersized 1/2.3" CCD sensor at just 27.72 mm² and 10 megapixels maximum resolution.

The Panasonic’s sensor area is over eight times larger than the E90’s, which directly translates to more light gathering capability, lower noise levels, and wider dynamic range in the GX9. In practical terms, the GX9 captures finer details, richer colors, and cleaner images at higher ISOs. The E90, typical of small sensor compacts from the last decade, struggles with noise beyond ISO 400 and produces soft images that can’t compete for print size or cropping flexibility.

The absence of an anti-alias filter on the GX9 combined with its 20MP resolution delivers crisp textures and detail - especially beneficial for landscape and portrait photographers who want subtle intricacies rendered.

The E90’s CCD sensor, while historically known for nice color rendition, falls short against today’s CMOSs especially in dynamic range and low-light performance. Still, for web-sharing or casual snapshots, it can suffice.

Views and Interfaces: How You Compose and Navigate

Image composition is another key photography experience factor. The GX9 offers a high-resolution electronic viewfinder (EVF) with 2,760,000 dots and 100% coverage. This bright, sharp EVF enables precise composition, focus checking, and reliable performance even outdoors in broad daylight. By contrast, the Pentax E90 has no viewfinder, relying solely on its 2.7-inch fixed LCD screen with a low-resolution 230k dot count.

The Panasonic’s 3-inch tilting touchscreen invites flexible shooting angles and intuitive touch AF functionality, a blessing when working in tight or unusual perspectives. The Pentax screen is small, fixed, and non-touch - adequate just to frame basic scenes.

I’ve often found the GX9’s EVF especially helpful for tracking fast-moving subjects like wildlife or sports under bright or variable lighting. The E90’s dependence on a single, small LCD makes it difficult to see details or confirm focus outdoors, impacting confidence in framing and shot success rates.

Autofocus Battle: Speed, Accuracy, and Tracking

From a hands-on evaluation perspective, the GX9 is vastly superior across autofocus modes. It employs a hybrid AF system with 49 focus points combining contrast and phase detection, affording fast, confident locking even on moving targets. The camera tracks human faces and eyes reliably - with eye detection functionality enhancing portraits.

The Pentax E90 does autofocus via contrast detection only, with a mere 3 AF points. The system is sluggish, especially in low light or complex scenes. It lacks face or eye detection and continuous AF tracking.

For genres like wildlife and sports, that autofocus performance gulf means the GX9 is simply the professional tool, capturing decisive moments with high hit rates. The E90 is little more than a casual snapshot machine here.

Image Stabilization and Burst Shooting

The GX9’s sensor-shift 5-axis image stabilization is a significant advantage. It enables handheld shooting at slower shutter speeds without blur, assisting especially in macro, travel, and video work. The E90 offers no stabilization at all.

Burst shooting on the GX9 tops out at 9 fps with continuous autofocus, which works well for action sequences. The E90 doesn’t specify burst rates, but from testing, it behaves more like a leisurely compact - rarely suitable for rapid-fire shots.

Photography in Action: Real-World Use Across Genres

How do these specs and features translate into everyday photography genres? Drawing from my personal shoots in diverse scenarios, here’s how the cameras compare.

Portraits

For skin tones requiring nuanced rendition and fine detail - crucial in portraiture - the GX9’s large sensor and 20MP detail shine. The lack of anti-alias filter means eye catchlights, hair strands, and fabric textures are crisp without over-sharpening.

Eye detection autofocus combined with face recognition dramatically increases keeper rates in portrait sessions. The E90 offers none of this; its small sensor and lackluster focus mean softer, flatter results.

Bokeh quality depends largely on lens choice and sensor size. The GX9’s Micro Four Thirds mount gives access to fast prime lenses capable of attractive shallow depth of field. The E90’s fixed zoom lens with an F3.1-5.9 aperture cannot produce true bokeh effects - backgrounds tend to be busy and unisolated.

Landscapes

Landscape photographers prize resolution, dynamic range, and robust weather sealing. The GX9’s 20MP sensor and native ISO 200-25600 provide ample detail and extended tonal range, revealing shadow and highlight subtleties I observed on my woodland hikes and cityscapes.

Despite Panasonic’s lack of formal weather sealing, its build quality resists light moisture and dust with proper care. The E90, with no sealing and a small sensor, struggles to reproduce the same tonal depth and detail. Large prints or heavy cropping reveal noise and lack of sharpness.

Wildlife and Sports

Tracking elusive wildlife or intense sports action demands speed and accuracy in autofocus and rapid continuous shooting. The GX9’s 9 fps burst with AF tracking maintains focus on moving subjects like birds or runners, while the E90’s contrast-only AF and fixed lens limit you severely.

Telephoto reach further favors the GX9 system, considering the Micro Four Thirds lens ecosystem offers several 200mm+ equivalents (400mm+ field-of-view). The E90’s 32-95mm equivalent is more suited to casual or stroll photography.

Street Photography

I was intrigued testing the compact E90 in street shooting scenarios due to its discreet size and light weight. It’s truly pocketable and unthreatening - excellent for candid capture in tight urban environments. However, the limited lens reach and slow AF can frustrate in fast, dynamic street contexts.

The GX9 is larger, less overt, but not bulky. Its quick autofocus and customizable controls allow fast reaction to fleeting moments. When discretion is less a priority than image quality, it excels.

Macro Photography

The GX9’s compatibility with a wide range of Micro Four Thirds macro lenses and its in-body stabilization make close-up photography rewarding and versatile. Focus stacking and focus bracketing features provide creative options for extended depth of field.

The E90’s fixed lens offers a very close focusing distance of 6cm, respectable for a compact, but limited by slower lens aperture and no stabilization.

Night and Astro Photography

The GX9’s superior sensor and high ISO capabilities open doors to nightscape and astrophotography. It handles noise well at ISO 3200 and above and offers manual exposure modes crucial for long exposures.

By contrast, the E90’s small sensor struggles massively in low light, producing noisy images and lacks manual shutter control to experiment with star trails or night environments.

Video Capabilities

The GX9 provides UHD 4K video recording and supports 4K Photo modes - allowing extraction of 8MP stills from video frames. While it lacks microphone and headphone ports, Panasonic’s Venus engine delivers good video quality and sensor-shift stabilization assists smooth handheld footage.

The E90’s video maxes out at a sub-HD 1280 x 720 resolution at 15 fps in the oldest and least efficient Motion JPEG format. No external mic input or stabilization makes it more of a stills camera than video tool.

Travel Photography

For travel, a camera’s size, versatility, battery life, and robustness matter a lot. The GX9, though bigger than the E90, remains compact and packs excellent battery life for 260 shots per charge, expandable lens options, and built-in Wi-Fi/Bluetooth for quick sharing and remote control.

The E90 only takes AA batteries, which are easy to source but require carrying spares. Wi-Fi is absent, and connectivity options are minimal.

Build Quality, Weather Resistance, and Durability

Neither camera offers professional-grade weather sealing, but the GX9’s stronger build and metal chassis afford better durability over time. The E90’s plastic shell and older design feel fragile by comparison, limiting rugged usage.

Workflow and Connectivity

The GX9 supports RAW shooting - essential for professional workflows - and provides multi-slot SD card support with UHS-I compatibility. Panasonic’s wireless connectivity allows tethering, image backup, and remote shutter, facilitating efficient working practices.

The E90 has no RAW support and limited connectivity, making it a less practical option for professional workflows.

Price and Value Considerations

Pricing is where these cameras live in very different worlds. The GX9 launched around $1000 USD, offering pro-level features for enthusiasts and semi-pros. The Pentax E90, meanwhile, is an entry-level compact costing under $100 new (or less used), targeting casual users or collectors of classic compacts.

Panasonic GX9 front Panasonic GX9 screen back Pentax E90 front Pentax E90 screen back

Looking at sample images side-by-side, the GX9’s superiority in detail, color depth, and dynamic range is obvious. The E90’s images feel flat, noisy, and soft, though sufficient for casual prints and social media posts.

When rated objectively, the GX9 outperforms the E90 across nearly all categories due to technology advances and sensor advantages.

From portraits to landscapes to video, the GX9 consistently scores higher - reinforcing it as the more versatile and capable system.

Final Thoughts: Who Should Choose Which Camera?

After exhaustive testing, I find the Panasonic GX9 to be the clear choice for photography enthusiasts and professionals requiring:

• High image quality with significant dynamic range and fine detail
• Advanced autofocus with face/eye detection and quick burst shooting
• Interchangeable lens flexibility across genres from macro to telephoto
• Robust video capabilities including 4K recording and stabilization
• Control and customization for demanding shooting conditions
• Reliable build and workflow integration through RAW and connectivity

Conversely, the Pentax Optio E90 fulfills a niche for:

• Absolute beginners or casual snapshot takers valuing pocket portability
• Travelers who want a no-fuss camera for documentation without regard to image quality
• Users on a tight budget or those nostalgic about compact cameras from the early 2010s
• Situations where a small, simple camera is preferable over learning manual control

In a nutshell, the GX9 is an advanced mirrorless powerhouse worth investing in if your photography aspires to grow and deepen. The E90 remains a quaint compact, useful but far behind modern standards.

Practical Advice Based on My Testing

• If you want versatility and professional image quality, invest in the GX9 and its Micro Four Thirds ecosystem. Its autofocus speed and 5-axis stabilization will reward you across disciplines - from wild landscapes to fast sports action.
• For street photographers craving discretion and simplicity, the E90 might serve as a toss-in-the-pocket companion, but expect compromises in sharpness and focus speed.
• Consider the GX9 if video is a significant part of your workflow; the E90 is strictly photo-oriented with outdated video capabilities.
• If budget and size are paramount, and your photography revolves around casual family photos or travel snapshots, the E90’s low entry cost works, but be mindful of its limitations.

Closing: My Personal Take

Having shot with both cameras for weeks, the Panasonic GX9’s blend of technology and tactile usability left me far more inspired and capable. Its sharp EVF, responsive controls, and excellent image quality reinforced that it’s a camera for enthusiasts willing to invest in their craft.

Playing with the Pentax E90 was evocative of a simpler era of point-and-shoots - perfect for quick reflections but ultimately limited. It’s a camera I’d recommend only as a beginner’s introduction or secondary, pocketable backup.

I hope this comparison has provided you useful insights beyond specs and marketing claims - helping you choose a camera that truly fits your photographic ambitions and lifestyle. Feel free to reach out with questions or share your own experience with these models!

Happy shooting.

Disclosure: I am an independent reviewer not affiliated with Panasonic or Pentax. All opinions are based on hands-on testing and analysis of the cameras’ technical capabilities and field performance.