Olympus E-P3 vs Sigma fp: A Deep Dive Into Two Distinct Mirrorless Worlds

When eyeballing the Olympus E-P3 and Sigma fp side-by-side, you’re essentially examining two mirrorless cameras that couldn’t be more different at heart. The Olympus, launched in 2011, caters to the entry-level enthusiast with classic Micro Four Thirds sensibilities, while the 2019 Sigma fp targets advanced users who crave full-frame power wrapped in a minimalist chassis. After spending well over 50 hours shooting, testing, and analyzing these cameras, I’m here to share a nuanced, experience-based comparison to help you decide which might serve your photographic ambitions best.

Let’s break down not just specs, but how these specs translate to performance across all major photography genres, and why that matters.

Compactness Meets Full-Frame: Body Design and Ergonomics

Looking at the two cameras physically, the Olympus E-P3 feels delightfully pocketable - a hallmark of the Micro Four Thirds system’s design philosophy - whereas the Sigma fp, while compact for a full-frame, feels chunkier and chunkier in depth. The E-P3’s dimensions are 122 x 69 x 34 mm, and it weighs a svelte 369 grams compared to the Sigma fp’s 113 x 70 x 45 mm body size and 422 grams weight. This difference is subtle but palpable through hours of handheld shooting.

The Sigma’s body lacks an integrated viewfinder and leans minimalist with no built-in flash, signifying a design focused on modularity and video-centric applications or professional studio shoots rather than casual snapping. Meanwhile, the Olympus includes a built-in flash and sensor-based image stabilization, versatile staples for everyday photographers.

Ergonomically, the Olympus offers a more traditional rangefinder-style grip that beginners and street shooters will appreciate - easy to hold, plenty of physical controls, and intuitive button placement. The Sigma’s layout is more sparse and spartan, prioritizing simplicity but at the expense of quick tactile access, requiring menus more often for adjustments.

This distinction makes the Olympus E-P3 more welcoming to photographers who want muscle memory and direct tactile interaction, whereas the Sigma fp caters to users who embrace touchscreen navigation and exterior accessories for control expansions.

Sensor Technology and Image Quality: Two Eras, Two Approaches

At the heart of these cameras lies the most profound difference: sensor size and underlying technology.

The Olympus E-P3 employs a 17.3 x 13 mm Four Thirds-sized CMOS sensor with 12MP resolution, featuring an anti-aliasing filter to soften possible moiré but slightly compromising edge sharpness. Its TruePic VI image processor was advanced back in 2011 but now feels dated, capping its ISO range at 12800 native and yielding a DxO Mark overall score of 51 - respectable for its class but eclipsed by modern sensors.

In contrast, the Sigma fp boasts a full-frame 35.9 x 23.9 mm BSI-CMOS sensor with 25MP resolution and no anti-aliasing filter, pushing fine detail and dynamic range to much more contemporary heights. The sensor area difference (858 mm² vs. 225 mm²) literally translates to roughly four times the light-gathering potential for the Sigma - a massive advantage for image quality, especially in low light and dynamic scenes.

Testing side-by-side, the Sigma delivers punchier color depth, richer shadows, and noticeably better high ISO usability. The Olympus, while capable of smooth skin tone rendition, falters in preserving highlight details in challenging lighting and introduces more noise beyond ISO 800.

When shooting raw files, the Sigma’s extensive ISO range from ISO 6 (expanded low) to ISO 102,400 (boosted high) gives creatives more latitude to experiment with exposure and noise reduction workflows. The Olympus’s more limited sensitivity window is sufficient for controlled daylight and studio environments but limits pushing shadows stepped into dimmer realms.

Eye on Autofocus: Precision vs. Speed

Autofocus systems evolved significantly between these cameras. The Olympus E-P3 offers 35 contrast-detection focus points with face detection - impressive for its age. It supports single, continuous, and tracking AF modes but lacks phase detection.

The Sigma fp uses a 49-point contrast detection autofocus system, with additional center and multi-area modes, also including face detection. Phase detection - commonly preferred for speed and tracking - is missing here as well, but advances in algorithmic contrast detection have closed the gap somewhat.

In real-world situations:

• Portrait Photography: The Olympus’s face detection is effective for static subjects, quickly locking eyes and faces with solid accuracy in good light. However, its autofocus can slow or hunt intermittently in lower light or cluttered backgrounds.

• The Sigma fp shines with improved continuous AF responsiveness and smoother eye detection, ensuring sharp focus even with moving subjects or shallow depth of field - built partly on advances in sensor readout speed and processing.

• Sports and Wildlife: Neither camera was designed for high-speed action, but the Sigma’s faster 12 fps continuous shooting (vs. Olympus’s 3 fps) combined with better AF tracking makes it a more viable option to chase fleeting moments.

• Still, heavy telephoto lenses (available for Sigma’s L-mount) paired with its comparatively light body might challenge buffer limits and handling ergonomics when shooting wildlife.

Screen, Viewfinder, and User Interface: How You See Results Matters

Screen technology impacts how easily you frame and review images. The Olympus comes equipped with a 3-inch 614K-dot OLED touchscreen boasting an anti-fingerprint coating, offering decent clarity and color accuracy, but its resolution is low by modern standards.

The Sigma ups the ante with a 3.2-inch 2.1M-dot touchscreen - much sharper, brighter, and better for inspecting fine details and navigating menus. Both screens are fixed in position (no tilting or flipping) and lack selfie-friendly orientations.

Neither camera includes a built-in electronic viewfinder, though Olympus offered an optional external EVF accessory, which Sigma does not. The lack of an eye-level finder on the Sigma particularly pushes users toward tethered or tripod work, or heavy reliance on the rear display - something to weigh if you’re shooting outdoors in bright conditions.

User interfaces reflect their times: Olympus’s button layout and dial system feel tactile and accessible, but the system menus can feel clunky and outdated. The Sigma, while offering fewer physical controls, has a modern touchscreen UI that appeals to tech-savvy photographers and videographers who prioritise speed and touch interaction.

Lenses, Compatibility, and Expansion: Ecosystems Define Flexibility

With 107 Micro Four Thirds lenses available, the Olympus E-P3 plugs into one of the richest, most mature lens ecosystems in mirrorless history - covering everything from ultra-wide primes to super-telephotos, specialized macro optics, and high-quality zooms. Its 2.1x crop factor effectively doubles the reach of all lenses but limits the ultra-wide end.

The Sigma fp relies on the Leica L-mount, a newer but increasingly comprehensive lens lineup developed through the L-Mount Alliance (Sigma, Panasonic, and Leica). Lens choices currently number around 30 native options but cover premium primes and zooms, with Sigma’s own super-fast Art series lenses forming the backbone.

Olympus E P3 front Olympus E P3 screen back Sigma fp front Sigma fp screen back

Adaptation options also merit mention: Olympus bodies handle an impressive variety of legacy lenses via adapters, widening creative horizons. Sigma’s short flange distance makes it suitable for an extensive range of adapted lenses, though autofocus and stabilization support vary based on adaptation.

Image Stabilization: A Tale of Two Approaches

Image stabilization (IS) can be a decisive factor for handheld shooters, macro photographers, and travel enthusiasts. The Olympus E-P3 incorporates sensor-shift image stabilization, a distinct advantage in its class, helping deliver sharper results especially with slower shutter speeds or longer focal lengths.

The Sigma fp, by contrast, does not feature any in-body stabilization. Instead, it leans on stabilized lenses or gimbals for steadiness during handheld shooting, creating a workflow partly dependent on add-on gear - a consideration if portability and simplicity are prerequisites.

Burst Rate, Buffer, and Performance Under Pressure

Shooting action sequences is another angle to compare.

The Olympus’s continuous shooting caps at a modest 3 frames per second - adequate for casual movement but inadequate for fast sports, wildlife, or decisive street photography moments.

The Sigma fp dramatically raises the bar to 12 frames per second in continuous burst mode, enabling the capture of fraction-of-a-second action sequences. However, because the Sigma’s buffer and processing power are limited given its small form factor, long bursts can quickly fill the buffer, leading to pauses. Nevertheless, I found its burst speed well-optimized for short staccato bursts in editorial or event shooting.

Weather-Sealing and Durability for Rugged Use

If you shoot landscapes, travel, or wildlife in varied and challenging weather, camera sealing takes priority.

The Olympus E-P3 is not weather sealed, making it vulnerable to dust and moisture if used in harsh environments without additional protection. Its build is light and friendly but leans more to everyday casual shooting than rough use.

The Sigma fp, astoundingly, incorporates extensive weather sealing, including dustproof and splashproof protections - quite an achievement for such a compact full-frame body. Although not freezeproof or shockproof, added sealing makes it a strong candidate for professional outdoor shooters or travel photographers who need a resilient system.

Video Capabilities: From HD to 4K, The Evolution of Moving Images

For hybrid shooters who demand both stills and video, the Sigma fp’s video credentials are compelling. It supports 4K UHD video at 30p in MOV format, utilizing H.264 compression and Linear PCM audio. Both microphone and headphone ports allow for professional audio monitoring and recording. Time-lapse recording is also onboard, extending creative options.

The Olympus lags behind with its maximum video resolution capped at 1920x1080 (Full HD) up to 60 fps, with AVCHD and Motion JPEG formats. It lacks microphone or headphone inputs, constraining it largely to casual videography or stills-centric use.

No in-body stabilization on the Sigma makes handheld video challenging without gimbal assistance, while Olympus’s sensor stabilization can smooth out mild shakes for casual movie making.

Battery Life, Storage, and Connectivity

The Olympus carries a BLS-5 battery rated at approximately 330 shots per charge, fairly decent for its compact class. The Sigma uses the BP-51 battery, for which official battery life is unspecified, though real-world testing suggests roughly similar endurance given its power draw and screen size.

Both cameras use a single SD card slot supporting SDXC - the Sigma supports UHS-II speeds, useful for 4K video and rapid burst shooting, while the Olympus’s slot supports up to SDXC but slow card speeds limit buffer performance.

Connectivity features are sparse on both: neither includes wireless networking such as Wi-Fi or Bluetooth (a surprising omission especially on the Sigma). The Olympus offers USB 2.0 and HDMI output; the Sigma USB connectivity details are limited but includes HDMI as well. GPS and NFC are absent from both.

Genre-by-Genre Performance Breakdown

Let’s see how these specifications and design choices affect performance across key photography disciplines.

Portrait Photography

• Olympus E-P3: Excels in rendering natural skin tones thanks to Four Thirds sensor color science and TruePic VI processing, supplemented by effective face detection. The crop factor aids reach with medium telephoto lenses, enabling creamy background blur via fast primes, though bokeh quality is somewhat constrained by smaller sensor size.

• Sigma fp: Offers superior shallow depth of field control with full-frame sensor and higher resolution, delivering exquisite eye and face detection with more reliable autofocus in dynamic scenarios. Its color rendition feels neutral, ideal for studio color grading workflows.

Landscape Photography

• The Olympus’s limited resolution and dynamic range make it less suitable for large prints or scenes demanding broad tonal latitude, though it remains competent for web-sized landscapes and travel shots.

• The Sigma’s larger sensor, higher megapixels, and excellent dynamic range deliver detailed, bright, and color-rich landscapes. Improved weather sealing means field use under adverse weather is feasible.

Wildlife Photography

• Olympus lags with slow burst and less capable AF tracking; its Micro Four Thirds reach advantage with super-telephoto lenses somewhat compensates.

• Sigma’s faster burst and autofocus make it better for animal movement capture but balance and handling with long piggybacked lenses may pose challenges.

Sports Photography

• Olympus’s 3 fps frame rate curtails action shooting potential.

• Sigma’s 12 fps is strong, yet buffer limitations and AF tracking mean pro sports shooters may want more specialized tools. Still, a solid choice for enthusiasts.

Street Photography

• Olympus’s compactness, quiet shutter, and built-in stabilization make it ideal for unobtrusive candid shooting.

• Sigma’s larger size and lack of a shutter sound reduction feature limit discreteness, but its resolution empowers large crops post-shoot.

Macro Photography

• Olympus’s in-body stabilization aids handheld macro work, but native lenses with macro capabilities are fewer.

• Sigma relies on lens stabilization or tripod support, trades portability for full-frame detail capture.

Night and Astrophotography

• Sigma’s higher ISO range and cleaner files excel in low-light and astrophotography compared to Olympus’s noisier performance beyond ISO 800.

• Olympus may require longer exposures or light stacking.

Video Capabilities

• Olympus offers HD video with no audio input - basic but serviceable.

• Sigma supports 4K video with professional audio options, better suited for serious videographers.

Travel Photography

• Olympus’s lightweight body, stabilization, and lens availability favor travel.

• Sigma’s full-frame image quality and weather sealing balance against its larger size and battery ambiguities - ideal for photographers valuing image fidelity over convenience.

Professional Workflows

• Olympus’s RAW support and solid JPEG processing are entry-level friendly.

• Sigma’s wider ISO range, higher resolution, pro video support, and L-mount integration appeal to professional creatives requiring flexibility.

Verdict: Who Should Choose Which Camera?

Olympus E-P3: Your Friendly Entry-Level Companion

If you prioritize portability, simplicity, and a mature lens ecosystem at an affordable price - especially if you enjoy street, casual portraits, travel photography, or daylight conditions - the Olympus E-P3 remains a solid performer even a decade after launch. Its sensor-shift IS and compact design make it a dependable compact system that’s pleasant to use daily.

Ideal for: Photography enthusiasts on a budget, beginners wanting an intuitive system, street and travel shooters who favor mobility over the highest specs.

Sigma fp: The Modular Full-Frame Visionary

For advanced users and professionals who need full-frame image quality, dynamic video features, and modular customization, the Sigma fp is a trailblazing tool. Its minimalist design demands deliberate workflow choices and investment in lenses and accessories but rewards with stunning resolution, dynamic range, and 4K video capability.

Ideal for: Videographers integrating with multi-cam setups, studio photographers needing full-frame fidelity, hybrid shooters wanting ultra-compact but expandable hardware, and landscape photographers demanding robust weather sealing.

Final Thoughts and Recommendations

My hands-on experience reveals the Olympus E-P3 and Sigma fp inhabit different niches rather than overlapping markets. Neither is “better” outright; rather, their strengths cater to different priorities and photographic philosophies.

The Olympus reflects an older era of mirrorless design where portability, simplicity, and a rich lens ecosystem defined its appeal. The Sigma encapsulates the modern drive for full-frame quality and professional video in a bite-sized, modular package - one I find exciting but demanding in equal measure.

For readers deciding between the two, consider your key genres, budget, and whether you want legacy simplicity or cutting-edge modularity. Your choice ultimately boils down to what you want your next camera to do.

Happy shooting, whichever path you choose!