Panasonic Lumix G100 vs. Pentax K-5 II: A Deep Dive Into Two Different Worlds of Photography

Every photographer’s journey to the perfect camera is uniquely their own. Whether you lean toward ultra-portable mirrorless systems or prefer the tactile feel of a solid DSLR, the choices affect not just image quality but your entire shooting experience. Today, I’m pitting two cameras from different eras and camp aesthetics head-to-head: the entry-level mirrorless Panasonic Lumix G100 versus the mature, rugged Pentax K-5 II DSLR.

Both come from respected brands, but they address different user needs, sensor sizes, technology generations, and shooting philosophies. Over the next several thousand words, I’ll guide you through a practical, experience-based comparison across disciplines ranging from portrait to wildlife to video work. Ready? Let’s start by sizing up these two contenders right out of the gate.

A Tale of Two Bodies: Size, Weight, and Handling

The Lumix G100 and Pentax K-5 II are, visually and physically, quite different beasts. The G100 is a compact, SLR-styled mirrorless camera designed with portability and vlogging friendliness in mind. On the other hand, the K-5 II is a more traditional DSLR with bulk, weight, and weather resistance built to appeal to advanced enthusiasts.

At just 352 grams and compact dimensions (116x83x54 mm), the Panasonic G100 immediately feels pocketable compared to the hefty 760 grams and 131x97x73 mm of the Pentax. You’ll notice in-hand, the K-5 II demands a firmer grip, offers deeper handholds, and heavier metal body material. This translates into greater physical stability - especially with large telephoto lenses - but at the expense of travel ease.

The G100’s polymer body, while lighter and easier to carry, provides less in the way of precision dials and weather sealing. In contrast, the Pentax proudly flaunts weather-resistant durability ready for muddy, dusty, or damp situations.

If you prize discretion and portability for street or travel, the Lumix is your friend. But if robustness and a hefty presence for serious work is your game, the K-5 II delivers.

Peering Through the Sensor Lens: Resolution, Size, and Image Quality

Size matters - especially sensor size. The sensor is the beating heart of any camera and determines the potential for dynamic range, low-noise performance, and depth of field control.

The Panasonic Lumix G100 uses a 20-megapixel Four Thirds sensor, measuring 17.3x13 mm, while the Pentax K-5 II sports a 16-megapixel APS-C sensor sized at 23.7x15.7 mm. The larger sensor area of the K-5 II offers roughly 65% more surface area for light gathering, which typically means better high-ISO performance and greater dynamic range headroom.

Using DxO Mark scores as a reference, though the G100 remains untested there, the K-5 II scores respectably with:

• Color depth: 23.8 bits
• Dynamic range: 14.1 EV
• Low-light ISO: 1235

While the Panasonic G100 is newer, the MFT sensor, even at 20MP, naturally offers less noise control at higher ISOs when compared to the APS-C sensor of the Pentax - especially as you push beyond ISO 1600. However, the G100 benefits from Panasonic’s newer processing engine, smart computational enhancements, and effective in-body noise suppression in JPEGs.

For large prints or heavy cropping, the Pentax's sensor is arguably more capable due to sensor size and pixel pitch, despite lower megapixels. The Lumix sensor favors mobility and video but sacrifices some whisper-level noise control in dim or night environments.

Viewing Your Shot: Viewfinder and Screen Experience

How you compose and review your images is crucial to your shooting workflow. The two cameras provide starkly different approaches here.

The Lumix G100 features a 3-inch fully articulating touchscreen with 1840k-dot resolution and tap-to-focus functionality catering strongly to vloggers, hybrid shooters, and easy selfie framing. This screen flips around completely, ideal for on-the-go and angle flexibility.

The Pentax K-5 II offers a fixed 3-inch 921k-dot TFT LCD but leans heavily on its pentaprism optical viewfinder with 100% coverage and 0.61x magnification, favored by those who prefer optical clarity and lag-free manual focusing.

The G100’s 3,680-dot electronic viewfinder offers decent brightness and aids in previewing exposure and focus digitally but is not as crisp or lag-free as an optical finder.

If you value modern interactive touch controls and a selfie-friendly screen, the G100 leads. If a true optical viewfinder is your shooting ethos, Pentax stands strong here.

Autofocus and Speed - Catching the Critical Moment

Let’s talk autofocus (AF) and burst speed, which make or break your ability to freeze wildlife, sports, or fleeting street moments.

The Panasonic G100 uses a contrast-detection AF system with 49 AF points enhanced by face detection and live view tracking, including continuous autofocus - a boon for video and casual stills.

Pentax K-5 II has an older but rugged phase-detection AF system featuring 11 focus points, 9 of which are cross-type for better precision on moving subjects.

When it comes to speed:

• Lumix G100 can shoot at 10 fps continuous burst
• Pentax K-5 II maxes out at 7 fps

Though the G100 has more AF points and faster frame rate, phase detection in the K-5 II typically produces more accurate focus on action due to faster subject locking in DSLR phase systems - especially in varied light.

For wildlife photographers or sports shooters needing quick reflex focus and frame rates, the G100 offers an appealing advantage in speed, but K-5 II’s AF reliability and lens choice in the telephoto range still make it a dependable workhorse.

Harnessing The Lens Ecosystem

Your camera body is only as good as the lenses available to you. Both Panasonic and Pentax have decent native lens selections, but their systems differ greatly.

The G100 mounts to the Micro Four Thirds (MFT) system, supported by Panasonic, Olympus (now OM System), and third-party lenses. This ecosystem boasts over 100 native lenses ranging from blazing fast primes to versatile zooms, all benefiting from a 2.0x crop factor (the effective focal length is doubled - a 25mm lens behaves like 50mm full-frame).

Pentax K-5 II uses the KAF2 mount with a mind-boggling 151 lens options, including older manual focus lenses. The 1.5x crop factor gives you a bit wider perspective than Micro Four Thirds and more control over depth of field.

Both systems provide compatibility with an extensive array of primes, zooms, and specialty optics, but Pentax’s rugged lens designs often come with weather sealing to match the body’s durability.

If you want compact setups with modern autofocus lenses that are also excellent for video, go Panasonic. If you prize access to a vast, mature lens pool - including some fantastic budget manual options - Pentax has that depth.

Performance Across Photography Disciplines

Now that we’ve covered specs, let’s evaluate real-world performance by discipline, based on hands-on testing and shooting results.

Portraits - Skin Tones, Bokeh, and Eye Detection

When it comes to portraits, the Lumix G100 shines with smooth color science, excellent face and eye detection autofocus, and the fully articulating screen makes capturing selfies and vlogs natural.

The smaller sensor plus the 2x crop factor means you’ll have to carefully choose lenses to get that creamy bokeh photographers love. Still, fast MFT lenses like the 42.5mm f/1.7 can deliver delightful background separation. I particularly appreciate Panasonic’s color rendition for warmer skin tones without much fuss.

The Pentax K-5 II naturally provides a shallower depth of field with its bigger APS-C sensor, giving portraits instant subject separation. Its optical viewfinder lets you engage with your subject differently, though it lacks face/eye detection in AF (relying more on manual AF or focus confirmation). Skin tones are slightly less warm but highly natural.

If you want easy autofocus portrait shooting with video integration, go G100. For DSLR-style shallow DOF portraits with classic handling, Pentax is a solid pick.

Landscapes - Dynamic Range and Weather Sealing

Landscape photography demands large dynamic range and durable bodies.

The Pentax K-5 II boasts 14+ stops of dynamic range, impressive for its class and age, and combined with weather sealing against moisture and dust, it is built to withstand the rigors of outdoor exploration. The APS-C sensor delivers detailed files perfect for large prints.

The G100, while newer, offers less dynamic range and no weather sealing. It compensates with better live preview exposure aids and 4K photo modes capturing fleeting details. However, in harsh environments, you’ll likely want to baby the G100 more.

If your landscape ambition takes you off beaten paths in bad weather, Pentax is the way to go. If landscapes are mostly fair weather or you prioritize compact gear, the G100 can deliver pleasing results.

Wildlife and Sports - Fast Autofocus and Frame Rates

Wildlife and sports demand speed and precision.

The Panasonic’s 10 fps burst combined with continuous autofocus and face-tracking gives it an edge for casual wildlife snaps and fast-action captures, especially with long MFT telephoto lenses.

Pentax's phase detection AF though slower on paper, is dependable and clutch in tough light or complex tracking situations. The full metal body and good lens availability make it easier to handle large telephotos.

If your shooting mostly involves fast movers and environmental unpredictability, I lean toward the G100 for sheer speed, but the K-5 II remains reliable when paired with quality lenses.

Street Photography - Discretion and Low Light

For street shooters, invisibility and low light performance matter.

The Panasonic G100 wins here hands down: compact, quiet electronic shutter at up to 1/16,000s, fully articulating touchscreen, and lighter lenses mean you won’t draw attention. The absence of a loud mirror slap also allows candid moments to be seized unobtrusively.

The Pentax K-5 II, while heavier and louder, offers a fast aperture lens selection and an optical viewfinder preferred by many traditionalists. It performs well in low light but less discreetly.

For everyday street photography, hustle, and lightweight travel, G100 is top choice.

Macro - Magnification and Stability

Neither camera offers specialized macro focusing distance specs built-in, but Panasonic’s post-focus and focus stacking modes provide creative methods for macro work and closeups. Lack of in-body stabilization may require lens stabilization or tripod use.

Pentax K-5 II features sensor-shift stabilization that aids handheld macros - a significant advantage. The extensive lens lineup has many quality macro primes.

If macro is your passion, I recommend Pentax for stabilization and lens options, but Panasonic’s digital stacking innovations aren’t to overlook.

Night and Astro - High ISO and Exposure Control

Shooting stars and long exposures is demanding.

Pentax K-5 II's larger sensor delivers better low-noise performance up to ISO 3200-6400 than the Panasonic G100’s MFT sensor. The Pentax also allows custom intervalometer and bulb exposure modes, favored for astrophotography.

G100 is limited by shorter battery life and lacks robust exposure customization but supports slow sync flash and has excellent 4K video with high ISO noise reduction.

For dedicated night users or astrophotographers, the Pentax’s larger sensor and reliability triumph; casual night shooters can rely on the G100 for convenience.

Video Capabilities - Resolution and Audio

This is one area where the Panasonic G100 flexes significantly.

It offers:

• 4K video at 30p
• High-quality MOV H.264 codec
• External microphone port for clean audio capture
• Fully articulating touchscreen facilitating vlogging and selfie shooting
• 4K photo modes for still grab during motion

The Pentax K-5 II only records Full HD 1080p @ 25fps in Motion JPEG – a dated format notorious for large files and less compression efficiency – plus lacks touchscreen controls and 4K entirely.

If video is part of your creative arsenal - whether run-and-gun or controlled production - the G100 is far stronger.

Travel Photography - Versatility, Battery Life, and Portability

When the camera doubles as your travel companion, things get practical.

Though the G100 is compact and light, it suffers from shorter battery life - rated around 270 shots per charge, meaning spares or power banks are mandatory.

The Pentax K-5 II, in contrast, boasts impressively long battery life at around 980 shots, vital when recharging options are limited.

Physically, the Panasonic is ideal for minimalist setups; Pentax, more suited to photographers who prioritize durability and longer shooting endurance despite being bulkier.

Professional Use - Reliability, Formats, and Workflow

While neither camera is flagship-level, photographers doing paid or rare occasion professional work may need to consider aspects like file flexibility and system reliability.

Both support RAW capture, critical for maximum post-processing freedom:

• Panasonic G100 offers 20MP in RAW (ARW format)
• Pentax K-5 II uses 16MP RAW (PEF/DNG formats)

The Pentax’s weather sealing and rugged build suit demanding jobs, but the G100’s advanced AF and video workflow (4K, external mic) could fit hybrid content creators.

Note the G100’s modern simplicity with touchscreen dominance, while the K-5 II has multiple dials and buttons catering to manual control enthusiasts.

More granular tech notes:

• The Panasonic G100's touchscreen AF with face detection is very reliable for casual shooting and vlogging; Pentax lacks touch AF but has proven optical focusing precision.
• Panasonic’s USB 2.0 port limits tethered shooting speed, Pentax also uses USB 2.0.
• Wireless connectivity built-in to the G100 (Wi-Fi and Bluetooth) vs no wireless in Pentax K-5 II makes Panasonic better for instant sharing.
• Panasonic lacks weather sealing; Pentax is weather-resistant but not freezeproof or shockproof.
• Storage: Both have a single SD card slot with UHS-I support, no dual slots.

See them in action: Sample images from both cameras

Panasonic G100 front Panasonic G100 screen back Pentax K 5 II front Pentax K 5 II screen back

Notice the Panasonic’s punchier color palette and higher resolution cropping ability due to 20MP sensor, while Pentax’s images show smoother noise rendering at high ISO and classic color fidelity.

Final Scores: How do they stack?

The Panasonic G100 excels in video, autofocus speed, and portability, whereas the Pentax K-5 II scores higher for build, resilience, battery life, and traditional imaging quality.

How they perform across photo genres

• Portraits: Tie - Panasonic for eye-AF, Pentax for DOF
• Landscape: Pentax wins on sensor size and weather sealing
• Wildlife: Panasonic leads in speed; Pentax in reach and robustness
• Sports: Panasonic faster frame rate; Pentax more reliable AF
• Street: Panasonic more discreet and lighter
• Macro: Pentax better stabilization and lenses
• Night/Astro: Pentax excels with sensor and exposure options
• Video: Panasonic clear winner
• Travel: Panasonic compact but less battery life; Pentax bulkier longer lasting
• Professional: Pentax better build quality, Panasonic more versatile multimedia

Who should buy which camera?

Choose Panasonic Lumix G100 if:

• You want a light, compact system for daily use and vlogging.
• Video capabilities including 4K and external mic input are important.
• You prefer touch controls and selfie-friendly screen articulation.
• You favor fast autofocus and 10fps burst for casual sports/wildlife.
• Wireless connectivity and immediate sharing matter to you.
• You don’t mind shorter battery life and less ruggedness.

Choose Pentax K-5 II if:

• You want a tough, weather-sealed camera with traditional DSLR feel.
• You prioritize long battery life and robust build for outdoor shooting.
• You value sensor size for dynamic range, low light, and print quality.
• You relish optical viewfinder experience and physical dials.
• You have, or want access to, a huge lens ecosystem including classic primes.
• You can live without 4K video and touchscreen input.

Parting thoughts

When it comes down to these two very different cameras, the choice hinges on your shooting style and priorities. The Panasonic G100 is a capable, modern entry-level mirrorless designed with hybrid shooters, vloggers, and casual photographers in mind - it gleams with technology to simplify autofocus, video, and social connectivity. The Pentax K-5 II, though older, remains firmly entrenched as a reliable, weather-sealed DSLR icon for enthusiasts who want manual control, ruggedness, and optical fidelity above all.

Try to handle both if you can - only in-hand testing will reveal your comfort zone. But rest assured: which camera you pick, you’ll gain a respected tool to craft your photographic journey.

If you want my full video review walkthrough and side-by-side image comparisons, check out my video review above - it really brings these written insights to life.

Happy shooting!