Olympus E-M1 vs Sony A77: An Exhaustive Comparative Review for Enthusiasts and Professionals

Selecting the right camera often involves dissecting intricate specifications, evaluating system usability, and relating those factors to one’s specific photographic needs. Here, we rigorously compare two seminal cameras in their own right - the Olympus OM-D E-M1 and the Sony SLT-A77 - highlighting their strengths, limitations, and practical applications. This analysis draws on extensive hands-on testing, sensor-level scrutiny, ergonomic assessment, and real-world shooting scenarios across multiple photographic genres.

Physical Form and Ergonomics: Handling and Design Philosophy

At the outset, the user interface and physical comfort significantly influence the shooting experience. The Olympus E-M1 is a compact mirrorless system camera adopting an SLR-style body, optimized for mobility without sacrificing manual control. The Sony A77, by contrast, employs a mid-size DSLR form factor with the added complexity of a translucent mirror mechanism (SLT), making it heavier and bulkier.

• Olympus E-M1: Measures 130x94x63mm, weighs approximately 497g (battery included).
• Sony A77: Substantially larger at 143x104x81mm and heavier at 732g.

This size differentiation translates into handling nuances. The E-M1’s smaller grip is better suited to prolonged handheld use or travel photography, whereas the A77’s heft offers superior balance when paired with longer telephoto lenses but may induce fatigue over extended sessions. Both cameras feature a robust control layout with physical dials and customizable buttons, but the tactile feedback and button placement favor the Olympus for one-handed operation in dynamic shooting situations.

Top-Deck Controls and User Interface

Control arrangement influences workflow efficiency. Our side-by-side top view comparison reveals that the E-M1 adopts a clean, logically segmented control scheme including dedicated exposure mode, ISO, and shutter speed dials. Meanwhile, the A77 offers an operational layout that reflects its DSLR heritage, with an additional top screen for quick status reference, something absent on the Olympus.

The Sony’s top LCD assists in managing settings without diverting gaze from the viewfinder, potentially beneficial for event photographers. However, the E-M1’s more minimalist top plate, augmented by a tilting touchscreen, provides quicker parameter adjustments during live view or video shooting.

Sensor Technology and Image Quality Metrics

A critical factor for any camera comparison is sensor capability, as this directly impacts resolution, dynamic range, and noise performance.

The Sony A77’s larger APS-C sensor delivers higher native resolution and marginally superior dynamic range and color depth, which pay dividends in landscape and studio photography where fine detail and tonality matter. The Olympus E-M1’s Four Thirds sensor, while smaller, is reinforced by Olympus’s TruePIC VII processor and advanced noise reduction algorithms, rendering acceptable low-light performance for its class.

Notably, the E-M1’s inherent 2.1x focal length multiplier affects lens selection and depth-of-field control. This margin requires consideration especially in portrait and macro photography contexts.

LCD Screens and Viewfinders: Visual Feedback and Composition

Both cameras utilize electronic viewfinders (EVF), a critical tool for modern mirrorless and SLT cameras. Their specifications are closely matched:

• Olympus E-M1 EVF: 2.36M-dot resolution, 100% coverage, 0.74x magnification
• Sony A77 EVF: 2.36M-dot resolution, 100% coverage, 0.73x magnification

The Olympus’s EVF delivers a slightly larger apparent image, arguably enhancing composition precision and manual focus accuracy. However, Sony’s traditional DSLR build with an updated translucent mirror means the hybrid EVF remains responsive even with long exposure and in low light.

On the rear, the E-M1 sports a 3-inch tilting touchscreen with 1037k-dot resolution, facilitating intuitive menu navigation and touch-to-focus during live view and video shooting. Conversely, the A77’s 3-inch fully articulating display lacks touch functionality and provides a lower 921k-dot resolution.

The touchscreen on the E-M1 improves focus targeting speed in complex scenes - a notable advantage for macro and wildlife shooters who benefit from rapid point selection.

Autofocus Systems: Complexity and Real-World Tracking Performance

Autofocus (AF) performance is often a decisive factor for dynamic and action photography. Each system’s AF delineation reflects distinctive philosophies.

• Olympus E-M1: Hybrid AF with 81 focus points; phase-detection and contrast-detection on sensor; face detection included. Supports continuous AF, tracking, selective, and center-area modes.
• Sony A77: 19 focus points with 11 cross-type; phase-detection AF; face detection enabled but lacks continuous tracking AF (no AF tracking).

Our testing reveals the Olympus E-M1’s AF performs well under varied conditions, especially in continuous AF and tracking subjects in motion, due in large part to its hybrid PDAF and CDAF system. The lens-sensor communication and contrast detection enhance accuracy during live view, essential for macro and video.

The Sony A77’s AF, while robust with phase detection and fast in stills capture, struggles slightly with tracking erratic subjects, especially in complex backgrounds or lower contrast scenes. However, when paired with proprietary Sony/Minolta Alpha lenses optimized for SLT, it exhibits swift, reliable single-shot autofocus.

This autofocus disparity is consequential for sports and wildlife photographers requiring rapid, precise focus locking on fast-moving subjects.

Burst Shooting and Shutter Mechanisms

Burst performance dramatically impacts action, sports, and wildlife photography outcomes.

• Olympus E-M1: 10 frames per second (fps) continuous shooting
• Sony A77: 12 fps continuous shooting

The Sony pulls ahead marginally in frame rates, aided by its SLT design which eliminates mirror blackout during shooting, allowing quicker live view frame captures. The Olympus’ mechanical shutter limits max shutter speed to 1/8000 sec but lacks electronic shutter options, preventing silent capture modes that some situations demand.

Shutter synchronization with flash has a maximum speed of 1/320 sec on the E-M1 and 1/250 sec on the A77, with the Sony supporting high speed sync (HSS), an advantage in complex studio lighting.

Lens Ecosystem and Mount Compatibility

Lens availability and system expandability shape long-term usability, impacting professional photographers especially.

• Olympus E-M1: Micro Four Thirds mount; access to over 107 lenses including from Panasonic, Olympus, and third parties. Many compact, high-quality primes and zooms.
• Sony A77: Sony/Minolta Alpha mount; larger ecosystem of 143 lenses, including legacy Minolta, Sony’s own lenses, and third-party providers.

The Micro Four Thirds system prioritizes portability and cost-efficiency, with exceptional lenses for macro, wide-angle, and portrait use at compact sizes. Conversely, the Sony A77's APS-C mount features more extensive full-frame lens compatibility (via adapters), generally offering superior optics, especially in telephoto primes essential for wildlife.

Lens weight and size differ accordingly: Olympus favors small-form-factor glass, whereas Sony lenses tend to be larger, affecting travel and street portability.

Build Quality and Environmental Resistance

Both cameras emphasize professional-grade construction.

• Olympus E-M1: Fully weather-sealed magnesium alloy body, resistant to dust, moisture (though not fully waterproof).
• Sony A77: High-grade polycarbonate with magnesium alloy chassis; sealed against splashes and dust but less extensive weather sealing.

The Olympus’s extensive sealing gives it an edge for outdoor photographers working in challenging environments, a clear benefit for landscape and wildlife photography in inclement weather. The Sony is robust but demands more care under adverse conditions.

Video Capabilities: Resolution, Frame Rates, and Audio

Video proficiency differentiates many modern cameras.

• Olympus E-M1: Full HD 1080p at 30 fps max; H.264 and Motion JPEG codecs; microphone input provided, but no headphone jack; no 4K modes. IBIS (5-axis sensor stabilization) improves handheld shooting.
• Sony A77: Full HD 1080p at 60 and 24 fps; AVCHD, MPEG-4, and H.264 support; microphone input present; no headphone jack; sensor-based IS but no 5-axis IBIS.

While the Sony offers more flexible frame rates in Full HD and superior codec options for efficient editing, the Olympus’s IBIS contributes to smoother, less shaky footage without gimbals, beneficial for travel and run-and-gun videography. However, both cameras are behind modern 4K standards.

Battery Life and Storage Flexibility

Battery endurance affects extended shoots and travel practicality.

• Olympus E-M1: Rated for ~350 shots per charge; uses BLN-1 battery.
• Sony A77: Rated for ~470 shots per charge; uses NP-FM500H battery.

The Sony guarantees longer operation per battery cycle, advantageous for event photographers and those at remote locations. Storage-wise, both cameras use a single card slot supporting SD cards; the Sony additionally supports Sony’s proprietary Memory Stick formats, though SD remains standard.

Connectivity, Wireless Features, and Extras

Connectivity largely influences tethering, remote capture, and sharing.

• Olympus E-M1: Built-in Wi-Fi for smartphone control, image transfer, and remote shooting.
• Sony A77: Eye-Fi wireless card compatibility (requires Eye-Fi card purchase), no built-in Wi-Fi or Bluetooth.

The Olympus offers native wireless ease-of-use absent in the Sony A77, affording real-time image review and control via mobile devices, a clear advantage for social media photographers and on-location workflows.

Detailed Genre-Specific Performance Insights

To deepen practical relevance, we examine the cameras’ aptitude across distinct photographic disciplines:

Portrait Photography

• Skin tones: Sony A77’s 24MP APS-C sensor provides higher resolution and better tonal gradation, resulting in finely detailed skin texture rendering. Olympus’s 16MP sensor remains very capable but with less resolution headroom.
• Bokeh and depth of field (DoF): Larger Sony sensor achieves shallower DoF more naturally, conferring advantage in subject isolation. Olympus’s Four Thirds sensor multiplication makes achieving creamy bokeh more challenging with standard lenses.
• Eye detection AF: Both feature face detection, but Olympus’s advanced contrast+phase AF hybrid yields higher eye detection accuracy - an important boon for wedding and portrait photographers relying on quick focus.

Landscape Photography

• Dynamic range: Sony A77’s sensor provides better dynamic range (13.2 EV vs 12.7 EV), reducing highlight clipping in high contrast scenes.
• Resolution: 24MP resolution captures finer detail in wide landscapes.
• Weather sealing: Olympus E-M1’s superior sealing better suits outdoor excursions involving moisture or dust.

Wildlife Photography

• AF speed and tracking: Olympus’s 81-point hybrid AF system and continuous tracking outperform Sony’s 19-point phase AF, especially for erratic subjects.
• Burst rates: Slightly slower at 10 fps, but with more reliable AF tracking.
• Telephoto lens availability: Sony’s larger lens selection and sensor size favor telephoto reach and image quality at distance.

Sports Photography

• Tracking accuracy: Olympus E-M1 leads in subject tracking performance.
• Low light frame rate: Sony offers faster burst (12 fps) and longer battery life, aiding extended sports coverage.
• Shutter blackout and lag: SLT system provides near-continuous live view on Sony, beneficial but partially offset by AF tracking limitations.

Street Photography

• Discreteness: Olympus smaller and lighter for unobtrusive shooting.
• Low light: Sony’s higher ISO native minimum and sensor area give cleaner night images.
• Portability: Olympus decisively more travel-friendly.

Macro Photography

• Magnification and focusing precision: Olympus supports focus bracketing and stacking, absent on Sony. The E-M1’s tilting touchscreen streamlines focus adjustments in tight macro compositions.
• Stabilization: Olympus’s 5-axis IBIS significantly aids handheld macro shooting.

Night and Astro Photography

• High ISO performance: Sony’s slightly superior low-light ISO score (801 vs. 757).
• Exposure modes: Olympus’s electronic shutter not available limits silent shooting modes beneficial for astro.
• Long exposure noise control: Both cameras provide long exposure noise reduction.

Video Capabilities

• Sony supports 60fps 1080p video; Olympus caps at 30fps.
• Olympus’s IBIS offers steadier handheld video.
• Both provide microphone inputs but lack headphone monitoring.
• Neither has 4K recording.

Travel Photography

• Olympus’s compactness, weather resistance, and wireless connectivity make it a top travel companion.
• Sony’s longer battery life counters its heavier bulk.
• Versatility depends on lens selections and personal shooting style.

Professional Workflows

• Both cameras provide lossless RAW formats.
• Sony’s wider dynamic range suits critical studio and commercial shoots.
• Olympus notes include focus bracketing/stacking support not matched by Sony.

Olympus E M1 front Olympus E M1 screen back Sony A77 front Sony A77 screen back

Examining matched sample images across these genres reveals tangible differences. The Sony files appear to have greater detail and shadow separation, while Olympus images benefit from excellent color fidelity and lower file size facilitating post-processing speed.

Overall Performance Scores and Value

The DxOMark-derived global scores place the Sony A77 at 78 and the Olympus E-M1 at 73 out of 100, reflecting sensor-driven advantages in resolution, dynamic range, and low-light capability.

Considering price (Olympus ~$799; Sony ~$899), the E-M1 provides compelling value in portability and usability, whereas the Sony offers advantages in sheer image quality and shooting speed.

Genre-Based Performance Breakdown

• Wildlife and sports photographers benefit from Olympus’s superior AF tracking despite slightly lower frame rates.
• Landscape and studio users favor Sony’s sensor resolution and dynamic range.
• Street and travel photographers prize Olympus’s compactness and wireless features.
• Video creators lean toward Olympus for stabilization, while the Sony’s higher frame rates are advantageous in some video styles.

Final Thoughts and Recommendations

Olympus OM-D E-M1
An expertly engineered mirrorless camera balancing portability, robust build, and versatile autofocus modes. Optimal for photographers valuing mobility - travel, street, macro/workflow requiring focus bracketing - and video shooters favoring stabilization. Its weather sealing and touchscreen are key differentiators. However, the smaller sensor limits resolution and low-light edge compared to APS-C.

Sony SLT-A77
An advanced DSLR hybrid delivering high-resolution imagery, dynamic burst capabilities, and a broad lens ecosystem. Strongly aligned to photographers needing fast, high-res stills in sports, portrait, and landscape arenas demanding superior tonal reproduction. The heavier, bulkier body and lack of modern wireless integration may impede portability and seamless sharing workflows.

Who Should Buy Which?

• Choose the Olympus E-M1 If: Your priorities are travel-friendly design, advanced in-body stabilization, superior AF tracking in wildlife/sports, and native wireless support under $800.
• Choose the Sony A77 If: Your workflow demands higher resolution, dynamic range, longer battery life, extensive lens options, and faster mechanical frame rates with an investment close to $900.

This side-by-side evaluation should inform your purchase decision grounded in technical rigor and user relevance, balancing sensor and system capabilities against operational nuances and real-life photographic scenarios.