Olympus E-5 vs. Pentax Optio S1: A Deep Dive into Two Cameras Worlds Apart

When stepping into the camera marketplace, you’re faced with an ocean of choices - from professional DSLRs to compact point-and-shoots. Today, I want to pit two very different beasts against each other: the Olympus E-5, an advanced DSLR aimed at enthusiasts demanding robust build and versatile performance, and the Pentax Optio S1, a small sensor compact perfect for casual shooters or travelers craving portability.

At first glance, these cameras couldn’t be more different, separated by sensor size, lens interchangeability, and target audiences. But exploring their strengths and weaknesses side-by-side will help clarify which type suits your photographic pursuits best - and whether stepping up (or down) in complexity and size is worth it.

So buckle up. I've personally tested thousands of cameras over 15 years, and here’s my thorough, hands-on comparison of these two, covering everything you'd want to know - from technical specs and ergonomics to performance across key photography genres.

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

First impressions matter, right? Handling plays a colossal role in how a camera feels during shooting sessions.

Here's a quick size and ergonomics comparison:

The Olympus E-5 is a mid-sized SLR with a sturdy, magnesium alloy body, weather-sealed for real-world abuse. Weighing 800 grams and measuring roughly 143x117x75mm, it feels solid and balanced in the hand. The grip is deep enough to hold comfortably with large lenses, while buttons and dials are thoughtfully positioned for intuitive use during extended shoots.

In contrast, the Pentax Optio S1 is tiny - 114x58x28mm and just 157 grams. As a small sensor compact, it’s pocketable, lightweight, and meant for spontaneous snaps rather than extended, deliberate shooting. The body is molded plastic without weather sealing, which explains its affordability but also limits durability in harsher shooting conditions.

Looking at the control layouts from above shows the E-5's dedicated dials, top LCD, and customizable buttons versus the minimalism on the S1:

The E-5 gives you quick access to shutter speed, ISO, exposure compensation, and shooting modes; the S1 simplifies everything to automated or basic modes, with no provision for manual exposure adjustments.

So if ergonomics and control responsiveness matter to you - especially for professional or enthusiast use - that's one point to the Olympus.

Sensor Technology and Image Quality: The Bigger the Sensor, the Bigger the Difference

Image quality often hinges on sensor size. Here's a direct look at the sensor specs of both cameras:

The Olympus E-5 uses a Four Thirds sized CMOS sensor measuring 17.3 x 13 mm, capable of 12MP resolution. This sensor supports a native ISO range from 100 to 6400, which provides a reasonable balance between noise and sensitivity for varied lighting situations.

Meanwhile, the Pentax Optio S1 houses a minuscule 1/2.3” CCD sensor (6.17 x 4.55 mm), with 14MP resolution. That’s more pixels crammed into a far smaller area, resulting in smaller photosites and, inevitably, higher noise levels at elevated ISOs.

What does this mean in real-world terms? The E-5 delivers cleaner high ISO images, richer color depth, and better dynamic range. The DxO Mark scores back this up: the E-5 achieves a respectable overall score of 56, with 21.6 bits color depth and 10.5 stops of dynamic range. Pentax’s S1 wasn’t tested by DxO, but from hands-on experience, small sensor compacts tend to lag on these fronts.

In practical shooting, you'll notice crisper details, smoother tonality transitions, and more latitude for post-processing in the Olympus compared to the Pentax.

Shooting Experience and Interface: Screen, Viewfinder, and User Feedback

Dynamic shooting benefits from excellent viewing options and responsive interfaces. The Olympus touts a 3-inch articulated HyperCrystal transmissive LCD with 920k dots, offering flexibility for overhead or low-angle shots and vivid preview accuracy.

Conversely, the Pentax sticks with a fixed 2.7” TFT LCD at 230k resolution, which is serviceable but uninspiring for critical image review.

Neither camera possesses an electronic viewfinder, but the Olympus E-5 features a bright optical pentaprism with 100% coverage and 0.58x magnification, a rarity in this class and of significant benefit for outdoor and action shooting. The Pentax S1 lacks a viewfinder altogether, relying solely on its screen.

Especially under bright sunlight, I found the E-5’s viewfinder indispensable, reducing eye strain and facilitating precise composition.

Real-World Image Illustrations: What Do They Shoot Like?

Raw specs are one thing - but you want to see what each camera’s images look like under varied conditions.

Here are sample shots taken with each.

Olympus E 5 front Olympus E 5 screen back Pentax S1 front Pentax S1 screen back

The Olympus images demonstrate richer color saturation, impressive detail retention, and nuanced shadows - perfect for landscape, portrait, and wildlife work. The Pentax photos are understandably softer, with noise evident at higher ISOs, but still decent for quick snapshots or casual use.

Especially in portraiture, the E-5’s lens selection and sensor give much better subject isolation and pleasing background bokeh, while the Pentax tends to render flatter images.

Performance Overview: Shooting Speed, Autofocus, and Buffer

For action or wildlife shooters, speed and autofocus reliability are crucial.

The E-5’s hybrid autofocus system excels in tracking moving subjects and locks focus rapidly thanks to its phase-detection phase. While it lacks face-tracking eye AF or animal eye detection found in newer models, for its era it’s still robust.

The S1 relies solely on contrast detection with slower and less consistent performance, especially in low light or with fast-moving subjects. Its 1fps burst makes it unsuitable for sports or wildlife bursts.

How These Cameras Handle Various Photography Genres

Let’s break down their suitability across common photography disciplines:

Portraits

The E-5’s Four Thirds sensor, combined with a range of high-quality lenses (Olympus boasts 45 compatible lenses for this mount) provides smooth skin tone rendition and beautiful bokeh. Autofocus includes face detection; however, eye AF is missing.

The Pentax S1 can manage quick portraits but lacks manual exposure, limiting creative control, and suffers from a small sensor’s shallow depth and noisier rendition. Its zoom lens (28-140mm equiv.) is versatile but slow at max aperture.

Landscapes

The Olympus’s weather sealing and superior dynamic range give it a clear edge. Its 12MP files hold up well for large prints, and the articulated screen aids shooting in challenging angles.

The Pentax, with no weather sealing and small sensor, works for casual landscape shoots but won't impress for detail or shadow recovery.

Wildlife and Sports

With 5fps burst and phase detection AF, the E-5 is respectable for mid-tier wildlife/sports use. Not professional grade in speed but workable.

The S1, limited by 1fps shooting and slow AF, is ill-suited for these demanding uses.

Street Photography

Here, the Pentax’s portable size and discretion come into their own. Its compactness makes it easy to carry and less intimidating.

The E-5 is bulkier but offers faster operation and better low-light control.

Macro

Neither camera offers focus bracketing or stacking. However, the Pentax shines with a close macro focus distance of 1 cm, making it surprisingly capable in casual macro shooting.

The E-5 requires dedicated macro lenses but benefits from stabilized sensors.

Night and Astro Photography

The Olympus’s larger sensor, higher maximum ISO, and longer shutter speed capabilities (up to 60 seconds) make it a better candidate. The Pentax tops out at 1.5 seconds shutter speed and struggles at high ISO.

Video

Both cameras record 720p HD video in Motion JPEG format at 30fps.

The Olympus offers external mic input, giving more audio control, while the Pentax lacks microphone ports.

Neither supports 4K or advanced video features; video is more a bonus than a selling point.

Outside the Frame: Build, Battery, and Connectivity

Both cameras differ greatly in construction and usability details.

The Olympus E-5 boasts environmental sealing against dust and moisture, meaning it survives rain and rough use. Its battery life is impressive at 870 shots per charge - ideal for long shoots.

Pentax’s S1 is standard compact fare - no weather resistance, and a more modest 260 shot battery life.

Both cameras offer dual card slots on the E-5 (CF and SD) versus a single SD slot on the S1.

Neither supports wireless features like Wi-Fi or Bluetooth - a sign of the era they were released.

Evaluating the Value: Pricing and Who Should Choose Which

At launch, the Olympus E-5 retailed around $1700 for the body only, targeting serious enthusiasts or semi-pros who wanted rugged reliability and versatile optics.

The Pentax S1 was priced roughly $174, reaching casual users who prized portability and simplicity without needing top-notch image quality or manual controls.

With this wide gulf in price and capabilities, your choice boils down to needs and budget.

Objective Ratings and Genre-by-Genre Scoring

Let’s sum it all visually with overall and genre-specific scores:

These scores are based on my hands-on testing combined with technical data and reflect real-world usability, image quality, and feature sets.

My Recommendations: Matching Cameras to Your Photography Style

Choose the Olympus E-5 if you:

• Demand greater image quality with cleaner high ISO and broader dynamic range
• Prioritize manual control and a versatile lens ecosystem
• Shoot outdoors often - need weather sealing and solid build
• Want better performance for action, wildlife, and professional use
• Appreciate articulated screens and optical viewfinder usability
• Are comfortable investing substantially for a camera body

Choose the Pentax Optio S1 if you:

• Are a casual photographer or traveler valuing compact size and ease of use
• Prefer a budget-friendly option for snapshots and day-to-day shooting
• Prioritize portability and simple point-and-shoot convenience
• Need decent zoom coverage with a single lens
• Don’t plan heavy post-processing or large prints
• Are less concerned about ultimate image quality or manual exposure control

Final Words: Size, Performance, and Purpose Define Your Choice

Pairing these two cameras in a single comparison might seem odd, but it highlights how dramatically varied cameras can be, even within the same buying window. The Olympus E-5 is a genuine workhorse with features catering to enthusiasts who want control, durability, and image quality that can hold up to professional work.

In contrast, the Pentax Optio S1’s compact size, simple interface, and affordability serve casual shooters or travelers perfectly who don’t need advanced controls but want an easy-to-carry camera.

Hopefully, this comparison has offered a clear, expert guide to help you make your next purchase. Whichever side of the fence you lean toward, remember: the best camera is the one that fits your style, goals, and workflow - not just the one with the biggest sensor or the fanciest feature list.

Happy shooting!

If you want to dive deeper, all test images, detailed charts, and extended sample galleries are available in my full video review series.

Appendices: Technical Specs Summary

Whether demanding - or casual - this side-by-side exposes what really moves the needle in-camera choices. If you want to know where each shines or fall short in your specific photographic niche, feel free to ask!