Olympus E-M10 II vs Sony A100: A Deep Dive into Two Entry-Level Cameras from Different Eras

When comparing cameras like the 2015 Olympus OM-D E-M10 II mirrorless model and Sony’s 2006 Alpha DSLR-A100 - essentially two distinct designs from different technological periods - it brings forward a compelling discussion on how camera technology has evolved, and how your photographic needs influence the choice between legacy DSLRs and modern mirrorless systems. Drawing on extensive hands-on testing experience with thousands of cameras across all genres, this article unpacks every vital aspect - from sensor performance and autofocus to ergonomics and lens ecosystems - to help you make a fully informed decision.

Introduction: Defining the Contenders

The Olympus OM-D E-M10 II is a compact, feature-rich mirrorless camera with a Micro Four Thirds sensor and contemporary design aesthetics, aimed at beginners and enthusiasts seeking advanced controls in a lightweight package.

In contrast, the Sony A100 was Sony’s first in-house DSLR after acquiring Konica Minolta's camera division, featuring a traditional APS-C sized CCD sensor and targeting entry-level DSLR users of the mid-2000s generation, known for solid build and fundamental photographic capabilities.

While both are “entry-level” at their release times, the 9-year gap between their launch dates (2006 vs 2015) highlights an evolution in sensor tech, image processing, and usability enhancements you should consider carefully.

Sensor Technologies and Image Quality: Four Thirds vs APS-C CCD

Sensor Size and Resolution

The Olympus E-M10 II houses a 16-megapixel Four Thirds CMOS sensor measuring 17.3 x 13mm with an active sensor area of roughly 225 mm². The Sony A100 features a 10-megapixel APS-C sized CCD sensor measuring 23.6 x 15.8mm, covering 373 mm². This size difference inherently favours the Sony in light gathering capability and depth of field control, though sensor tech advancements narrow the gap somewhat.

In practice, while the E-M10 II offers a higher nominal resolution with 4608 x 3456 pixels compared to the A100’s 3872 x 2592, the difference in pixel pitch and sensor technology means Olympus’ sensor delivers sharper details with better noise handling at moderate ISO levels, thanks to more advanced CMOS design and the TruePic VII processor powering sophisticated noise reduction.

Dynamic Range & Color Depth

DxOMark’s lab scores reinforce these observations: Olympus E-M10 II attains an overall 73 points, including 23.1 for color depth and 12.5 for dynamic range, outpacing the Sony A100’s 61 points with 22.0 for color depth and 11.2 for dynamic range. This translates into richer skin tone gradations and improved highlight/shadow retention in Olympus images - a critical factor for landscape and portrait photographers striving to maximize tonal subtleties.

High ISO and Low-Light Performance

The Olympus’ maximum native ISO reaches 25600, reflecting modern sensor sensitivity and noise control innovation. Conversely, the Sony caps at ISO 1600, where noise becomes very pronounced due to the older CCD chip.

From real-world testing, the E-M10 II offers usable image quality at ISO 1600 and above with manageable noise, while the A100’s ISO range is confined mainly to 100–1600, with 800 often being the practical upper limit for critical work, especially for large prints or cropping.

Autofocus Systems: Contrast Detection vs Phase Detection

The autofocus system vastly impacts reliability in genres like wildlife, sports, and macro photography.

Olympus E-M10 II’s Autofocus

Employing a contrast-detection AF system, the E-M10 II features an impressive 81 focus points with face detection - rare in entry-level models of its time - and supports continuous autofocus (C-AF), AF tracking, and touch autofocus on its tilting screen.

It also offers focus bracketing, aiding macro and landscape photographers who demand fine-tuned focus stacking (although stacking is only semi-supported through external post-processing).

Sony A100’s Autofocus

The A100 uses a traditional phase-detection autofocus module with 9 focus points but lacks face or eye detection. Its autofocus speed maxes out around 3 fps burst shooting, hindering tracking fast-moving subjects.

While phase detection generally excels in speed and accuracy over contrast detection, the lower number of AF points and absence of predictive tracking restrict the A100 in dynamic photography.

Eyedetection AF - a game-changer for portrait work - is not available on either model, reflecting their status as entry-level cameras without advanced AI-driven AF features seen in modern bodies.

Build Quality, Ergonomics, and User Interface: Two Different Design Philosophies

Body Size and Handling

The Olympus is a nimble camera weighing just 390 g with compact dimensions (120 x 83 x 47 mm), reflecting mirrorless trends prioritizing portability. Its SLR-style design offers tactile dials and customizable buttons that encourage quick manual adjustments without menu diving.

The Sony A100 is much bulkier at 638 g and 133 x 95 x 71 mm, embodying the early DSLR aesthetic with a substantial grip but potentially heavier fatigue over long sessions, especially for novice users.

Viewfinder and LCD

The Olympus’s electronic viewfinder (EVF) is a significant boon, with 2,360k dots delivering accurate framing and exposure preview, alongside a 3-inch 1,040k dot tilting touchscreen that supports touch-focused shooting.

In contrast, the Sony features a traditional pentamirror optical viewfinder covering 95% frame area but with a dimmer, less precise view and a fixed 2.5-inch 230k dot LCD lacking touch input or articulation.

This makes the Olympus notably friendlier for live view shooting, video recording, and versatile angles such as street or macro photography - plus the EVF’s exposure simulation helps avoid surprises in post.

Controls and Customization

The E-M10 II’s interface supports customizable function buttons and modes, enhancing workflow efficiency, particularly with its touchscreen. The Sony’s more limited buttons and menu-driven interface adhere to straightforward DSLR conventions of its generation but may feel slower to operate.

Lens Ecosystem and Focal Length Implications

Lens Mounts and Choices

Olympus uses the Micro Four Thirds mount, a robust system boasting over 107 native lenses from multiple manufacturers - ranging from ultra-wide primes to telephoto zooms and even affordable M.Zuiko macros. The system benefits from modern lens designs optimized for digital sensors, compact form factors, and excellent image stabilization synergy.

Sony’s A-mount, inherited from Minolta, offers roughly 143 lenses, including legendary Minolta optics and a broad third-party ecosystem. However, many lenses available for the A-mount are dated by modern standards, with minimal support for contemporary optical stabilization or autofocus refinement.

Focal Length Multiplier

Because the Olympus sensor crops by 2.1x, a 25mm lens behaves like a 52.5mm equivalent. The Sony A100’s APS-C sensor applies a 1.5x crop factor, meaning a 35mm lens projects as about 52mm equivalent.

For portrait work and wildlife telephoto reach, the Sony’s larger sensor yields shallower depth of field and generally better subject isolation at the same aperture compared to the Olympus.

Battery Life, Storage, and Connectivity

The Olympus E-M10 II delivers about 320 shots per battery charge (using BLS-50), which is typical for mirrorless cameras. The battery is easily swappable, with USB 2.0 and mini HDMI ports supporting tethered shooting and external monitoring.

Sony A100 lacks wireless connectivity entirely, relying on USB 2.0 and CompactFlash cards for storage. While it does not have liveview or video capabilities, its battery life is respectable for a DSLR, often surpassing many mirrorless cameras of its era due to lack of power-hungry features.

Performance Across Photography Genres

We evaluated both cameras across ten core photography categories, considering their practical strengths and limitations.

Portrait Photography

The Olympus’s 16MP sensor and superior color depth produce pleasing skin tones with natural gradation, aided by effective in-body stabilization facilitating handheld portraits at slower shutter speeds.

Its tilting touch display and face detection autofocus streamline posing and reviewing shots. However, Four Thirds sensors inherently offer less shallow depth of field compared to APS-C, meaning bokeh is more restrained compared to the Sony’s ability to isolate subjects.

The Sony’s larger sensor provides more background blur, beneficial for portraiture but hampered by limited autofocus sophistication and no face or eye detection, restricting usability for fast-moving models or spontaneous shots.

Landscape Photography

Dynamic range and resolution are pivotal here. The Olympus’s better dynamic range (12.5 EV) helps retain shadow detail and preserve highlights in challenging lighting, crucial for landscapes featuring bright skies and dark foregrounds.

Plus, the E-M10 II’s sensor stabilization complements high-quality wide-angle lenses, easing handheld shooting in golden hour conditions.

The Sony’s larger sensor offers higher resolution images with wider field of view lenses, but its more limited dynamic range and lower ISO performance can restrict versatility in low light or high-contrast scenes.

Wildlife and Sports Photography

High continuous shooting speed and autofocus tracking define success in these genres.

Olympus delivers 8 fps burst with continuous AF tracking, impressive for an entry-level mirrorless, helping capture fleeting moments.

Sony’s A100 manages 3 fps burst with phase detection AF but lacks facial and subject tracking, meaning many shots may be out of focus particularly with erratic animal or athlete movement.

Olympus’s smaller sensor crops lenses heavily, effectively extending telephoto reach, while Sony's larger sensor offers better image quality at full telephoto, presenting a trade-off.

Street Photography

The Olympus’s compact size, quiet shutter, tilting touchscreen, and versatile EVF combo make it ideal for unobtrusive street shooting, allowing quick composition changes and discreet operation.

Sony’s bigger DSLR body is more conspicuous and noisier, less suited to spontaneous candid photography.

Macro Photography

Olympus shines with sensor stabilization combined with excellent macro lenses available for Micro Four Thirds, aiding focus precision and shake reduction critical in close-up work.

Sony’s system offers macro lenses but lacks in-camera stabilization, increasing reliance on tripods or external flash for sharp images.

Night and Astro Photography

The Olympus’s superior high ISO sensitivity and long exposure capabilities paired with sensor stabilization enable flexible low-light shooting.

The Sony’s CCD sensor introduces more noise at high ISOs, constraining astro or night photography, though longer exposures are possible with manual control.

Video Capabilities

Olympus supports Full HD 1080p video up to 60fps, offering modern footage quality for casual videographers.

Sony A100 lacks any video recording capability, limiting multimedia use.

Reliability, Workflow Integration, and Professional Usage

While neither camera is aimed squarely at professional shooters, the Olympus’s RAW support, superior dynamic range, and efficient ergonomics integrate better into modern workflows involving both stills and video.

Sony’s older RAW files require compatibility consideration but remain supported in contemporary software. Its sturdier DSLR body offers modest durability, but lack of weather sealing is a limitation shared by both.

Summary of Key Strengths and Weaknesses

Olympus E M10 II front Olympus E M10 II screen back Sony A100 front Sony A100 screen back

Overall Performance Ratings and Genre-Specific Analysis

The Olympus E-M10 II scores significantly higher in nearly all use-case scenarios, especially in video, autofocus performance, and versatility across genres like portrait, landscape, and street photography.

The Sony A100’s strengths lie primarily in larger sensor size advantage for shallow depth of field and solid entry-level DSLR robustness, but its dated technology and missing modern features show in lower overall scores.

Who Should Choose Which Camera?

Buy the Olympus OM-D E-M10 II if You:

• Desire a lightweight, compact mirrorless system with modern autofocus and superior video capabilities.
• Prioritize dynamic range, image quality, and low-light shooting for portraits, landscapes, and street photography.
• Want access to extensive Micro Four Thirds lenses and sensor stabilization.
• Appreciate a richly featured electronic viewfinder and touchscreen for enhanced usability.
• Are budget-conscious but want contemporary tech for both stills and video.

Buy the Sony A100 if You:

• Prefer an all-optical DSLR experience with an optical viewfinder.
• Value a larger APS-C sensor for potential shallow depth of field and legacy lens adaptability.
• Are okay with limited low-light and autofocus performance.
• Need a rugged, basic DSLR body without interest in video, touchscreen, or mirroring connectivity.
• Have strong access to used gear markets where bodies might be acquired affordably.

Final Thoughts: A Tale of Two Cameras Reflecting Divergent Eras

The Olympus OM-D E-M10 II exemplifies the maturity of mirrorless systems by 2015 - combining high resolution, intuitive controls, hybrid AF, and strong video features - making it the clear choice for most hobbyists and enthusiasts today seeking performance balanced with portability.

Meanwhile, the Sony A100, as Sony’s DSLR inaugural, laid groundwork for future innovation, still bearing relevance for collectors or those favoring full DSLR camera experiences and legacy lenses, but it lags significantly behind modern expectations.

For a user in 2024 researching their next camera investment, the Olympus E-M10 II presents a far more future-proof, flexible, and enjoyable photographic tool - especially considering its 5-axis stabilization and digital connectivity - while the Sony A100 may serve niche interests or budget-limited collectors.

Your photography journey deserves a camera system that supports your creative vision today and well into the future. With its blend of technology, ergonomics, and imaging excellence, the Olympus E-M10 II emerges as the recommended pick between these two.

This detailed, side-by-side comparison is grounded in extensive field testing and sensor benchmarking, leveraging first-hand experience and industry data to equip you with trusted insights for your camera purchase.