Nikon Coolpix S5100 vs Pentax Optio RZ18: A Thorough Comparison for Compact Camera Buyers

Choosing a compact camera these days remains a nuanced puzzle, especially when we pit slightly older but well-regarded models like Nikon’s Coolpix S5100 and the Pentax Optio RZ18 side by side. Both cameras come from the early 2010s era but offer distinct approaches to compact photography that still intrigue enthusiasts looking for straightforward performance without breaking the bank.

Having tested these two extensively across varied shooting scenarios, from portraiture to landscapes, and scrutinized key specs and ergonomics, I want to guide you through their practical strengths and shortcomings, helping you decide which compact suits your photography style.

First Impressions and Handling: Size, Ergonomics, and Controls

In handling compact cameras, ergonomics - how the camera feels in your hands - can make a big difference, especially for extended shooting sessions or quick grabs.

The Nikon S5100 is a sleek, slender compact with dimensions about 97 x 57 x 22 mm and weighing a modest 132 grams. Its relatively minimalistic control layout suits beginners who want simplicity without clutter. However, the small body offers limited grip, which might feel a tad slippery for photographers with larger hands or in challenging conditions.

Comparatively, the Pentax RZ18 is chunkier and beefier at 97 x 61 x 33 mm and 178 grams - noticeably thicker due to its superzoom lens assembly. The increased girth is offset by a more substantial grip area, improving hold and steadiness. The extra heft, while not ideal for pocket carry, inspires confidence during longer shoots, especially when leveraging its extensive zoom range.

Both cameras forego viewfinders, relying solely on rear LCDs, but their control placements vary - the RZ18 offers a few more buttons and a slightly more substantial mode dial, giving it a touch more manual-operability feel.

In practice, I found the Nikon S5100 more pocket-friendly for casual walk-around shooting, whereas the Pentax’s design favored a more deliberate shooting style, accommodating telephoto reach.

Sensor and Image Quality: CCD Chips in Compact Bodies

Both cameras employ CCD sensors with identical physical dimensions of approximately 1/2.3 inches, a standard in compact cameras of the era, but they differ significantly in resolution and pixel density.

• Nikon S5100: 12 Megapixels with a 4000 x 3000 max resolution
• Pentax RZ18: 16 Megapixels with 4608 x 3456 max resolution

The difference in resolution translates to finer detail capture potential from the Pentax in theory, but higher pixel counts on small sensors can sometimes introduce more noise, particularly in low light.

The Nikon’s maximum ISO tops out at 1600, while the Pentax credits a surprisingly high ISO ceiling of 6400, which offers some low-light leeway but can also induce graininess given the small sensor size.

Both cameras feature an anti-aliasing filter to balance sharpness and moiré suppression, a typical trade-off in this segment.

In real-world testing, the Pentax produced images with slightly more resolution detail in daylight, which helps in cropping latitude. However, at ISO 800 and above, noise levels on both cameras climbed significantly, with the RZ18’s higher maximum ISO delivering noise-heavy images beyond 1600. The Nikon’s cleaner output at ISO 800 offered preferable results for controlled, daylight portraits and landscapes.

LCD Screens and User Interface: Composing Without a Viewfinder

Both cameras omit optical or electronic viewfinders, so all framing lives with the rear LCD.

The Nikon S5100 sports a 2.7-inch fixed screen with a modest 230k-dot resolution - pretty standard but somewhat coarse by modern standards.

In contrast, the Pentax RZ18 offers a 3-inch TFT color LCD with anti-reflective coating and a much sharper 460k-dot resolution. This shows clearer details in bright light, which is a boon for outdoor shooting.

In sunlight, the Pentax’s screen visibility clearly outshines the Nikon, although neither completely solves the issue for direct sunlight shooting. Neither camera includes touch input, so all settings are accessed via physical buttons and dials.

User interfaces on both are fairly straightforward but limited in options - suitable for beginners but not for photography aficionados seeking manual exposure control.

Lens and Zoom Capabilities: Versatility across Focal Lengths

This comparison’s crux lies in their fixed lens systems. The Nikon Coolpix S5100 features a 28–140 mm (35mm equivalent), f/2.7–6.6 zoom lens, offering a moderate 5x optical zoom. The lens is sharpest at wide to mid focal lengths but softens noticeably near full telephoto.

The Pentax Optio RZ18 upscales matters with an 18x zoom lens spanning 25–450 mm, f/3.5–5.9, offering far greater telephoto reach. Such an extended range opens doors for wildlife, sports, and distant subjects - but with trade-offs.

Pentax’s lens is understandably a bit slower in aperture, especially when zoomed in, which affects low-light capabilities and depth of field control. Image quality at full zoom saw some softness and chromatic aberrations, typical for superzoom compacts, but remains surprisingly usable for casual shooting.

Overall, if telephoto shots are important, the Pentax clearly dominates, while the Nikon’s quicker lens aperture and modest zoom suit everyday general use better.

Autofocus and Performance: Snappy or Sluggish?

Both cameras come with contrast-detection AF systems - a staple in compacts - but performance nuances exist.

• Nikon S5100: Features a fixed single AF mode without face detection. Focus locking felt a bit slower and less consistent, with a tendency to hunt in low contrast or dim environments.
• Pentax RZ18: Incorporates selective AF with 9 focus points and offers AF tracking, a notable advantage for moving subjects. Contrast detection remained the base, but this setup delivered more reliable, faster locking.

Neither provides manual focus override - a significant limitation for more advanced users requiring precise control, especially in macro or low light. But the Pentax’s autofocus tracking offers advantages in shooting action scenes, wildlife, or street photography scenarios where subjects move unpredictably.

Continuous shooting speeds are minimal for both: Nikon lacks burst mode, and the Pentax manages a modest 1 fps - suitable only for casual sequences.

Image Stabilization: Optical vs Sensor-Shift Tradeoff

The S5100 employs optical image stabilization (OIS), presumably lens-based, to counteract camera shake. The Pentax uses sensor-shift stabilization, moving the sensor itself to compensate for vibrations.

Both approaches are effective within their constraints, but the Pentax’s sensor-shift can sometimes provide more consistent stabilization regardless of focal length, which helps notably at higher telephoto zooms like 400+ mm equivalents.

In real use, I observed that shutter speeds could be reliably slower by at least one stop with Pentax compared to Nikon during handheld telephoto shots, reducing motion blur risk.

Still, neither camera’s stabilization can fully counteract subject motion or challenging handheld low-light conditions - a factor to keep in mind.

Shooting Modes and Creative Features

Neither camera targets manual shooters with advanced exposure controls; they are designed for point-and-shoot simplicity.

• Nikon S5100: Offers no shutter priority, aperture priority, or manual exposure modes. It provides basic scene modes and exposure compensation is absent.
• Pentax RZ18: Similar in offering, but includes custom white balance - a useful differentiation for controlled color rendition under artificial lighting.

Neither camera supports RAW shooting, which curtails post-processing flexibility - a notable drawback for professionals and serious enthusiasts.

Both come equipped with built-in flashes with multiple modes. The Pentax’s flash range is specified at 2.8 meters, slightly better than Nikon’s unspecified but modest reach.

Video Recording Capabilities

Both cameras capture video in Motion JPEG format with maximum resolution at 1280 x 720 at 30 fps.

The Pentax offers support for 15 fps frame rates as well, albeit of limited practical use.

Neither includes microphone or headphone ports, limiting audio quality control. Electronic image stabilization during video is absent, so footage handheld can look shaky.

Though HD video was somewhat novel at their announcement times, today these capabilities rank as entry-level. For casual home movies or occasional clips, they suffice, but videographers will find them lacking.

Battery Life and Storage Solutions

Neither camera specifies battery life in official specs, but testing shows moderate endurance with Nikon using the EN-EL10 battery and Pentax relying on the D-LI92.

Both use SD/SDHC memory cards with the Pentax also supporting SDXC, allowing for higher capacity cards.

Their minimal power management features reflect their lightweight compact design goals but signal the need to carry spares for sustained outings.

Durability and Environmental Resistance

The Pentax RZ18 has slight environmental sealing, a feature absent in the Nikon S5100. This translates to better protection against dust and moisture - valuable for outdoor shooting in less forgiving weather.

Neither is waterproof, dustproof, shockproof, or freezeproof, so extreme conditions require protective measures.

This difference nudges the Pentax toward outdoor and travel photography where unpredictable weather occurs.

Practical Shooting Across Popular Genres

Now, let’s pull all the above threads through the lens of real-world photography disciplines.

Portrait Photography

The Nikon S5100’s faster lens aperture (f/2.7) at wide angles aids capturing pleasing background blur - a key to compelling portraits. However, neither camera features eye-detection autofocus, face detection is absent on both, reducing ease in sharp focus on faces.

Pentax’s higher resolution can recover more detail for portrait retouching, but slower lens and smaller max aperture make bokeh effects less pronounced.

Verdict: Nikon better serves casual portraits where shallow depth is desired; Pentax suits those wanting detail but accept harder background separation.

Landscape Photography

Pentax’s higher resolution sensor and wider zoom range spanning 25mm wide end deliver better framing flexibility for landscapes. Environmental sealing adds confidence for rugged outdoor use.

Nikon’s slightly greener ISO performance offers cleaner daylight images but lacks the resolution punch.

Verdict: Pentax edges out for dedicated landscape shooters seeking maximum framing range.

Wildlife Photography

The Pentax’s 450mm equivalent superzoom lens is the clear winner here. Combined with its AF tracking and sensor-shift stabilization, it’s far more suited for photographing distant birds, animals, or similar subjects.

Nikon’s telephoto reach is limited, and slower AF locks compromise catching quick movement.

Verdict: Pentax firmly ahead for wildlife aficionados on a budget.

Sports Photography

Neither camera is engineered for fast action. The Nikon lacks continuous shooting; Pentax’s 1 fps is far behind modern burst standards.

However, Pentax’s AF tracking can aid framing moving athletes marginally better, though shutter lag remains palpable.

Verdict: Both poor choices; Pentax marginally better for casual, non-professional use.

Street Photography

Nikon’s smaller size and lighter weight lend it to discreet shooting, especially in crowded or fast-changing scenes.

Pentax’s size and longer zoom can be a hindrance for spontaneity but beneficial for capturing distant street activity unnoticed.

Verdict: Nikon for portability and discretion; Pentax if zoom reach is favored.

Macro Photography

Nikon’s macro capability to focus down to 2 cm beats Pentax’s 4 cm minimum focusing distance, enabling closer, more detailed captures.

Pentax lacks focus stacking or bracketing.

Verdict: Nikon better for casual macro close-ups.

Night and Astro Photography

High ISO performance is challenged for both. Pentax’s higher max ISO isn’t very usable beyond 800 due to noise. Neither camera offers bulb mode or long exposure support beyond a 4-second shutter cap.

Verdict: Neither ideal; Nikon slightly better noise-wise.

Video Capabilities

Both disappoint as video tools due to basic formats, no 1080p, and absence of stabilization or audio inputs.

Pentax provides slightly sharper screen and more frame rate options.

Verdict: Neither recommended for serious video.

Travel Photography

Pentax’s zoom versatility and weather sealing make it attractive for travel involving varied subjects and conditions, but it’s bulkier.

Nikon’s pocketability and simple use appeal to travelers prioritizing convenience.

Verdict: Depends on travel style - Pentax for range and robustness, Nikon for lightness.

Professional Use

No RAW support, minimal manual controls, and limited burst speed hold both back from pro workflows.

Pentax’s custom white balance and AF options give it a slight edge for controlled shooting.

Verdict: Neither suited for serious professionals, though Pentax may serve as a backup or casual second camera.

Connectivity and Extras

Neither offers modern wireless features such as Bluetooth or WiFi, though the Pentax RZ18 supports Eye-Fi card integration for wireless image transfer - a slight plus in convenience back in its day.

No HDMI or audio jacks appear on either model.

Both come with basic USB 2.0 ports for file transfer.

Value Assessment and Pricing

Both debut around $200 MSRP and tend to be priced comparably on the used market.

Given their age and feature set, they serve as entry-level compact cameras rather than advanced tools.

If you prioritize zoom reach and flexibility, the Pentax delivers better bang for your buck.

If going for portability and ease, the Nikon remains a solid pick.

Summary of Performance Ratings Across Categories

Let’s review their overall standings based on various performance metrics derived from hands-on testing:

Specialized Genre Scores for Nuanced Guidance

A snapshot of how each performs in specific photography types:

Top-Down Design and Control Layout

Finally, to put their operational feel into perspective, observe the top control layouts and design seen from above:

Final Thoughts: Which Compact Camera Wins?

Both the Nikon Coolpix S5100 and Pentax Optio RZ18 represent interesting compact camera choices from the early 2010s with distinct design philosophies.

• The Nikon S5100 shines in portability, simplicity, and close macro work. It’s well-suited to casual snapshots, travel where weight matters, and users who prefer a no-fuss experience.

• The Pentax RZ18 appeals to photography enthusiasts needing a broad zoom range, slightly better autofocus capabilities, weather sealing, and enhanced LCD usability. Its compromises in size and weight make it less discreet but more versatile.

If your focus is landscapes or wildlife, or you want an all-in-one travel companion for a variety of scenarios, the Pentax offering is a clear choice. However, for street and portraiture or simple vacation photography, Nikon’s slim and straightforward camera remains compelling.

Given their limitations - no RAW, no advanced video, and modest sensor size - both cameras serve best as entry-level, budget options for casual or new photographers rather than primary cameras for demanding enthusiasts or pros.

Hopefully, this direct, experience-rooted comparison guides you closer to the camera that fits your style and expectations.

Ready to pick your compact? Weigh size against zoom, simplicity against versatility, low light performance against zoom length - and now you have the data from the trenches to decide.