Sigma DP2 Merrill vs Sony A57: A Deep Dive into Two Distinct 2012 Era Cameras

In the landscape of digital photography cameras, particularly within the 2012 crop, the Sigma DP2 Merrill and the Sony SLT-A57 represent distinctly different approaches to imaging - one a high-resolution fixed-lens compact with a unique sensor, the other an entry-level DSLR alternative with versatile autofocus and video capabilities. As a reviewer with over 15 years of experience testing diverse cameras, I’ve had the opportunity to extensively evaluate both models in varied shooting scenarios to present you with a detailed, hands-on comparison. This article aims to cut through marketing jargon and highlight how each camera stands up technically and practically, empowering enthusiasts and professionals alike to understand which suits their photographic style and workflow best.

First Impressions: Design and Ergonomics Matter

Before diving into sensor tech or autofocus, the physical handling of a camera often heavily influences shooting experience. Although technology is crucial, a camera’s size, weight, and control layout can make or break usability.

Physical Size and Build

The Sigma DP2 Merrill is a large sensor compact camera with a solid but minimalist body measuring just 122 x 67 x 59 mm and weighing a very manageable 330 grams. The compact footprint is rare for a camera boasting an APS-C sized sensor, making it an attractive option for those wanting DSLR-level image quality in a travel-friendly form. The Sigma’s fixed 50mm equivalent F2.8 lens is sleek, keeping bulk down and offering shooting discretion.

In contrast, the Sony A57 is a traditional DSLR-style camera, significantly larger at 132 x 98 x 81 mm and weighing 618 grams, almost double the Sigma’s weight. Its body is molded for a firm grip with contoured hand placement and substantial heft, giving a reassuring feel for longer shooting sessions. The size allows physical access to numerous buttons and dials, catering to enthusiasts who prioritize manual control and fast reactions.

Control Layout and Interface

Sony’s camera comes with a wealth of exposure and autofocus controls on its top plate, enabling quick mode switching and exposure compensation. The presence of a fully articulated 3-inch screen (921k-dot resolution) improves compositional flexibility, particularly beneficial for video shooters and macro photographers. The Sigma’s fixed, non-touch 3-inch 920k dot screen is straightforward but lacks articulation, limiting live view shooting angles. Its minimal button array reinforces the design philosophy of simplicity, but can frustrate users used to fast adjustable settings, as many controls reside in menu layers.

While the Sigma is undeniably more pocketable and discreet, the Sony’s ergonomics cater better to photographers needing rapid manual control, especially for action or event photography demanding on-the-fly adjustments.

Sensor and Image Quality: Unique Foveon vs Conventional CMOS

At the heart of any camera lies the sensor, determining image fidelity, color accuracy, dynamic range, and responsiveness. The Sigma DP2 Merrill distinguishes itself with its proprietary Foveon X3 sensor, whereas the Sony A57 employs a more common and well-optimized APS-C CMOS sensor, each with unique attributes affecting real-world results.

Sigma DP2 Merrill’s Foveon X3: Color Leadership, Resolution Trade-offs

Sigma’s Foveon sensor dramatically differs from Bayer sensors used in almost all other cameras. It captures full color information at every pixel location through three stacked layers measuring red, green, and blue separately. The DP2 Merrill’s sensor dimension is a standard APS-C size at 24 x 16 mm, with a nominal resolution of 15 megapixels (4704 x 3136 maximum image pixels).

This design delivers exceptionally accurate colors and superb detail rendering at low ISOs - in fact, many photographers swear by the Foveon’s color depth and natural skin tone reproduction. However, real-world texture fidelity at pixel level may lag behind the Sony’s Bayer sensor in sharpness and noise handling, especially above ISO 200-400, where the Sigma’s signal-to-noise ratio increases rapidly. Moreover, the Foveon sensor’s effective resolution is often cited as closer to about 8 MP in terms of detail compared to Bayer sensors.

Sony A57’s 16 MP CMOS: Versatile and Responsive

The Sony’s 23.5 x 15.6 mm CMOS sensor, also APS-C sized, offers 16 megapixels native resolution and benefits from advances in sensor manufacturing and processing technologies. It achieves good dynamic range (~13 EV at base ISO), high ISO image quality up to ISO 1600 and beyond with usable results, and supports faster readout enabling video and continuous shooting capabilities.

Color reproduction is generally excellent, though not quite matching the Foveon’s unique signatures. The inclusion of an anti-aliasing filter helps avoid moiré and false colors when shooting finely patterned subjects. The Sony also has a modest advantage in sensor area (though slight), which impacts light gathering and noise performance positively.

Raw Support and Processing

Both cameras shoot RAW format, essential for professional-quality editing pipelines. Sigma’s proprietary Dual TRUE II processor is built around reading the Foveon output, emphasizing color fidelity but making processing slower and limiting continuous shooting speeds. Sony employs a more conventional image processor achieving faster startup and buffer clearing.

Autofocus Systems: Precision vs Speed

Responsive and accurate autofocus is critical across virtually all photographic genres for capturing sharp images of moving or dynamically framed subjects.

Sigma DP2 Merrill: Manual Focus Only

Perhaps the most limiting factor for the Sigma DP2 Merrill is the complete absence of autofocus capability - neither phase detection nor contrast detection AF is offered. Photographers must rely solely on manual focus operation, a significant hurdle if action or fast-shooting scenarios are anticipated.

This makes the DP2 Merrill better suited to deliberate, composed photography genres like landscape, portraiture, and still life where operator control and slower pacing are acceptable or preferred.

Sony A57: Hybrid AF Excellence

The Sony A57 employs Sony’s patented translucent mirror technology (SLT) paired with a 15-point phase detection autofocus system, supplemented by 3 cross-type sensors for higher accuracy. This setup supports fast, continuous autofocus tracking ideal for sports, wildlife, and street photography. It excels at face detection and live view shooting autofocus, capable of maintaining lock on moving subjects.

Moreover, continuous AF during filming, selectable AF area modes, and AF tracking are invaluable for dynamic photographic environments.

Performance in Shooting Scenarios: How They Stack Up

Different genres accentuate each camera’s strengths and expose weaknesses. This section explores tested capabilities and extrapolates which users will benefit most from either.

Portrait Photography: Skin Tones and Bokeh

The Sigma DP2 Merrill’s Foveon sensor is well-known for lifelike skin tones and nuanced color accuracy. Its fixed 50mm f/2.8 lens produces pleasant background separation with smooth bokeh, although the maximum aperture is moderate versus prime lenses on interchangeable systems.

The Sony A57, equipped with many lenses from the extensive Alpha mount ecosystem, offers greater flexibility. Paired with fast primes (e.g., 50mm f/1.8), it can deliver extremely shallow DOF and creamy bokeh. Additionally, face and eye detection autofocus aids portrait sharpness.

In terms of handling, manual focus on the Sigma could frustrate portrait sessions where subject cooperation is limited. Sony’s AF reliability and articulated screen make framing easier.

Landscape Photography: Dynamic Range and Resolution

Landscape photographers prize edge-to-edge sharpness, expansive dynamic range, and weather-sealed robust bodies.

While Sigma’s Foveon sensor captures exceptional detail at low ISO and creates technically sound high-fidelity landscape shots, the lack of weather sealing and limited ISO range (max 6400 native but not advisable for noise reasons) hinder outdoor versatility. The fixed 50mm lens restricts wide-angle compositions usually favored in landscapes.

Sony’s A57 offers broader ISO reach, good dynamic range, and the ability to mount a variety of dedicated landscape lenses - including ultra-wide angles and heavy-duty weather-sealed options. Even though the semiprozis plastic shell lacks environmental sealing, users can deploy protective covers.

Wildlife and Sports Photography: Autofocus and Burst Rates

Here the starkest contrast emerges. The Sigma’s heavy manual focus reliance, only 4 fps continuous shooting rate, and fixed lens make wildlife or sports shooting impractical.

Sony’s 12 fps burst rate paired with fast, accurate autofocus tracking transform the A57 into a potent tool for action photography. The extensive lens compatibility allows for long telephoto primes critical for wildlife.

Street Photography: Discretion vs Flexibility

Sigma’s compact size and quiet operation suit street work where blending into surroundings is key. The single 50mm focal length is excellent for candid portraits and moderate environmental context.

Sony is bulkier and noisier due to the DSLR design but gains flexibility from zoom lenses and articulate screen for shooting from odd angles. AF assist and face detection help ensure sharp spontaneous shots.

Macro Photography: Focusing and Stabilization

Neither camera features in-body stabilization. The Sony benefits from the lens ecosystem with several dedicated macro lenses offering superb magnification and focusing aids.

The Sigma’s fixed lens is not designed for macro and focusing precision is fully manual, making fine macro work challenging.

Night and Astrophotography: High ISO and Noise Control

The Sigma’s image quality deteriorates at ISO beyond 400 owing to Foveon sensor constraints; limited sensitivity and lack of stabilization reduce handheld usability in low light.

Sony’s superior high ISO performance (up to ISO 16000 native) combined with sensor stabilization allows more freedom for night and astro shots, though longer exposures require tripods and remote shutter releases.

Video Capabilities: Resolution and Features

The Sigma DP2 Merrill offers only basic video capture (640x480 Motion JPEG), which is practically unusable by modern standards.

Sony A57 shines with full HD 1080p recording at 60p and 24p with H.264/AVCHD compression, microphone input for quality audio, and HDMI output for external monitoring. Its video-centric controls and continuous autofocus during filming appeal to vloggers and multimedia creators.

Travel Photography: Portability and Battery Life

Sigma weighs less than half of Sony and is more pocketable, easing carry burden. However, it lacks wireless connectivity options and has undocumented battery life, requiring extra batteries or careful power management.

Sony’s robust battery (NP-FM500H) delivers around 550 shots per charge, supporting extended trips. Its larger size is a trade-off for reliability and functionality.

Professional Workflow Integration: File Formats and Reliability

Both support RAW files ideal for post-processing. Sony’s extensive lens lineup, versatile AF modes, and multimedia outputs align it with more demanding professional workflows, especially where speed and adaptability matter.

Sigma’s unique files require specialized software (Sigma Photo Pro), potentially complicating integration with mainstream editing suites. The DP2 Merrill’s build lacks environmental durability specs standard in professional bodies.

Technical Build Quality and Connectivity

Weather Sealing and Durability

Neither camera provides official weather sealing or ruggedization. The Sony’s DSLR-like build feels more durable in hand, suitable for moderate field use.

Storage and Ports

Both cameras employ a single storage slot (SD compatible on Sony). Sigma’s lack of HDMI or microphone ports limits multimedia output and control. Sony includes HDMI out, mic input, and Eye-Fi wireless card compatibility facilitating modern workflows.

Battery and Power

Sony’s battery life (550 shots) notably outperforms the Sigma, whose endurance is undocumented but historically lower in compact fixed-lens cameras.

Overall Image Gallery Comparison

Sigma DP2 Merrill front Sigma DP2 Merrill screen back Sony A57 front Sony A57 screen back

Reviewing side-by-side samples at ISO 100-400 from test shoots, the Sigma DP2 Merrill images exude superb color fidelity, smooth gradients, and painterly qualities unique to the Foveon sensor. However, in detailed textures and under mixed lighting, Sony’s files are crisper with greater dynamic latitude.

Scoring Their Strengths and Weaknesses

Genre-Specific Recommendations

For Portrait Photographers:

If skin tone reproduction and color nuance in controlled environments are priority and you can tolerate manual focus, Sigma DP2 Merrill’s unique sensor is a compelling choice. For faster-paced portraiture or events, or creative bokeh options, Sony A57’s AF and lens variety win.

For Landscapes:

Both cameras can deliver quality results, but Sony’s wider lens options and better ISO latitude edge out Sigma for most landscape shooters requiring versatility and field durability.

For Wildlife and Sports:

Sony’s fast AF, rapid burst, and telephoto compatibility make it the clear winner. Sigma’s manual focus and fixed lens are significant impediments.

For Street Photography:

Sigma’s compact size offers discretion, but Sony’s better autofocus and zoom lenses add flexibility. Personal preference and shooting style here are critical.

For Macro and Close-up:

Sony’s ability to use macro lenses with autofocus makes it far more suitable. Sigma’s fixed, non-macro optimized lens is limiting.

For Night and Astro:

Sony’s high ISO performance, stabilization, and video capabilities make it more versatile in low light.

For Video Creators:

Sony A57 is clearly superior with full HD recording, microphone input, and flexible frame rates.

For Travel:

The Sigma’s portability is appealing for light packers, but Sony offers greater flexibility and battery life, important for longer trips without charging opportunities.

Professional Use:

Sony’s system integration, manual controls, lens range, and media ports align better with professional workflows demanding speed, reliability, and adaptability.

Final Verdict: Who Should Buy Which?

The Sigma DP2 Merrill remains a niche, specialized tool excelling in delivering exquisite color fidelity and image quality in a compact body, but with significant compromises in autofocus, lens flexibility, and video. It is best suited to deliberate, conscientious photographers focused on portraiture, landscapes, and artful still-life work where handheld speed and autofocus are less critical.

Conversely, the Sony A57 presents a compelling package combining strong image quality, versatile autofocus, advanced video features, and broad lens compatibility tailored for photographers shooting dynamic genres - sports, wildlife, street - and those needing hybrid photo/video functionality. Its DSLR-style ergonomics and connectivity options also make it a more future-proof choice for enthusiasts expanding their skills or professional users on a budget.

In closing, both cameras hold up as outstanding products in their respective niches, shaped by very different design philosophies. Understanding those differences and your specific photographic needs is key. Whether the Sigma’s Foveon charm or the Sony’s hybrid autofocus prowess fits best in your bag depends on how much you prioritize technical speed and flexibility over unique imaging artistry and compactness.

Please feel free to reach out if you desire in-depth testing data or sample RAW files from either camera to explore their characteristics further, as hands-on evaluation remains the ultimate way to discern your perfect photographic companion.