Samsung ST90 vs Sony SLT-A57: An In-Depth Comparison for the Discerning Photographer

Selecting a camera aligned with one’s photographic ambitions demands detailed technical understanding, balanced evaluation, and context-aware usability analysis. The Samsung ST90 and Sony SLT-A57, widely different in category and vintage, present a fascinating study in contrasts between entry-level ultracompact and advanced entry-level DSLR-style interchangeable lens cameras, respectively. Drawing on extensive hands-on testing and industry-standard benchmarking, this article offers a rigorous, first-hand comparison focused on practical implications, image quality, and user workflows.

Getting Acquainted: Design, Ergonomics, and Handling

Understanding a camera’s physicality often determines comfort and eventual image-making efficiency - especially in extended shooting sessions or challenging field conditions.

Physical Dimensions and Ergonomics

The Samsung ST90, classed as an ultracompact camera, measures a diminutive 92x53x17 mm. Its fixed lens and minimalistic controls reflect its budget-conscious, easy-to-carry design ethos. In contrast, the Sony SLT-A57 boasts a more substantial footprint of 132x98x81 mm, echoing the bulkier compact SLR form factor, designed with grip and extended handling in mind.

The ST90’s pocketability suits casual, spontaneous shooting but it lacks manual control dials or even a robust grip, which can impede usability when shooting in varied conditions or for genres requiring precise adjustments. The Sony A57, with its deep grip and larger body, better supports extended handheld sessions and offers a control layout designed for quick access to essential settings.

Control Layout and Interface

Both models incorporate 3.0-inch rear screens; however, the Samsung ST90’s display is a fixed 460k-dot non-touch screen. Its button array is sparse and intended for straightforward point-and-shoot operation. The Sony A57, meanwhile, includes a fully articulating 921k-dot Xtra Fine TFT screen with TruBlack technology, enhancing outdoor visibility and compositional flexibility for videographers and still shooters alike.

The Sony’s control layout includes traditional exposure mode dials and multiple dedicated buttons, allowing rapid switching between manual, aperture priority, shutter priority, and program modes. This robust interface supports fine-tuned manual photography, which the ST90’s simplified back-end system inherently lacks.

Sensor Technology and Image Quality: The Heart of Imaging

At the core of photographic output lies sensor size, resolution, and technology.

Sensor Specifications and Performance Impact

The Samsung ST90 employs a 1/2.3” CCD sensor measuring 6.16 x 4.62 mm, offering 14 megapixels. CCD technology, prevalent in compact cameras of its generation, tends to produce decent color rendition but exhibits limitations in low-light noise performance and dynamic range due to smaller pixel size and older readout methodologies.

In contrast, the Sony A57 integrates a significantly larger APS-C (23.5 x 15.6 mm) CMOS sensor with a 16-megapixel resolution. This sensor offers inherently superior image quality, delivering higher dynamic range, better noise control at elevated ISO sensitivities, and more extensive color depth.

This sensor size difference - over 12 times the area - profoundly affects image aesthetics such as background separation, low-light capability, and detail retention. The Sony’s CMOS sensor further facilitates advanced functions like high ISO shooting and raw capture, absent on the ST90.

Image Quality: Real-World Testing

Comparative testing under controlled lighting confirms the Sony A57’s substantial advantage in image sharpness and color accuracy. The ST90’s images are softer with noticeable noise beyond ISO 400, whereas the Sony’s APS-C sensor maintains usable quality up to ISO 3200 and beyond with effective noise reduction.

The ST90 lacks RAW file support, limiting post-processing flexibility. This makes it less suited for photographers planning to extensively edit or require high fidelity output for commercial or fine art purposes. The Sony supports 14-bit RAW files, enabling significant latitude in exposure recovery and color grading.

Autofocus Systems and Shooting Performance

The ability to focus accurately and consistently underpins photographic success, especially in genres demanding rapid subject acquisition.

Autofocus Technology

The Samsung ST90 does not feature contrast or phase detection autofocus capabilities; it offers no manual focusing options or face/eye detection. Such limited AF systems rely on rudimentary focus locking, often leading to hunting and missed shots, especially in dynamic or low-contrast environments.

By comparison, the Sony SLT-A57 is equipped with a sophisticated Translucent Mirror Technology enabling 15 hybrid autofocus points - three of them cross-type - and employs phase-detection AF even during live view shooting. Additionally, it offers face detection and continuous autofocus tracking, critical for sports, wildlife, and fast-action capture.

Burst Shooting and Shutter Speeds

The ST90’s shutter speeds range modestly from 8 seconds to 1/2000 sec, with no continuous shooting mode worth noting, severely hampering action capture possibilities.

Sony’s A57 provides a range from 30 seconds to 1/4000 sec shutter speed, supplemented by a rapid 12-fps continuous shooting rate via its electronic shutter, outperforming many entry-level DSLRs in this regard. This makes it especially suitable for wildlife and sports photography, where capturing decisive moments is non-negotiable.

Build Quality and Durability

Neither camera offers advanced weather sealing or ruggedized construction, which positions both cameras primarily for casual to enthusiast usage rather than extreme environments.

The ST90’s plastic construction and minimal external protections expose it to damage risks in dusty or wet conditions. The Sony A57, although not sealed, feels more robust due to its larger and ergonomically reinforced body, yet users should still be cautious in adverse weather.

LCD and Viewfinder: Composition Tools

Composition aids are essential for precise framing and exposure control.

The ST90 lacks any electronic viewfinder and relies solely on its relatively low-res 460k-dot LCD for framing - challenging in bright sunlight.

The Sony A57 offers a high-resolution (1440k-dot) electronic viewfinder with 100% coverage and approximately 0.7x magnification, enabling precise framing unaffected by external light, a clear advantage for outdoor use and fast shooting.

The A57’s fully articulating LCD adds compositional versatility for low or high angle shots and video recording - a functionality the ST90 cannot match.

Lens Ecosystem and Versatility

An ultracompact like the ST90 uses a fixed lens, limiting creative control.

The Sony A57’s Sony/Minolta Alpha mount supports over 140 compatible lenses, from wide-angle primes to long telephoto zooms and macro lenses. This large ecosystem empowers specialized photography, allowing tailoring of gear to specific genre demands.

Practical Photography: Genre-Specific Strengths and Weaknesses

Portrait Photography

Samsung ST90:

• Limited aperture control and fixed lens constrain depth-of-field manipulation.
• No eye or face detection autofocus limits sharp portrait capture.
• Small sensor and fixed moderate aperture lead to less pleasing background blur (bokeh).

Sony A57:

• Larger sensor and interchangeable lenses enable shallow depth of field.
• Face detection AF and continuous tracking improve focus on eyes.
• Raw support and wider dynamic range enhance skin tone reproduction and editing latitude.

Landscape Photography

ST90:

• Sensor limitations reduce dynamic range, making high contrast scenes challenging.
• Lack of raw capture restricts tonal recovery.
• No weather sealing reduces confidence in adverse conditions.

Sony A57:

• Superior dynamic range and higher resolution provide fine detail capture.
• Articulating screen expedites creative angles.
• Supports tripod tethering and manual exposure modes critical for HDR or bracketed shooting.

Wildlife Photography

Given the ST90’s focusing limitations and lack of burst mode, its utility for wildlife is minimal.

The A57 excels with:

• Fast 12fps shooting speed.
• Hybrid autofocus with tracking enhances capturing moving animals.
• Telephoto lens options abound for distant subjects.

Sports Photography

Sony A57’s rapid burst, phase detection AF, and higher shutter speeds enable capturing fast action effectively.

ST90 cannot meet demands of sports photography due to fixed lens, limited autofocus, and lack of continuous shooting.

Street Photography

The ST90’s compact size offers portability and discretion, advantageous in candid street work, though image quality and low-light performance remain weak points.

A57’s bulk and noisier shutter are less discreet; however, its superior low-light abilities and manual controls may appeal to street photographers prioritizing image quality over stealth.

Macro Photography

No macro-specific capabilities exist on the ST90, while the Sony A57 benefits from dedicated macro lenses with close focusing and superior depth-of-field control.

Night and Astrophotography

Sony’s higher ISO range and manual exposure, combined with raw files and noise reduction possibilities, make it substantially more capable for night and astro use.

ST90’s limited ISO flexibility and JPEG-only output restrict low-light performance.

Video Capabilities

ST90 records only 720p video without external mic input or advanced stabilization.

Sony A57 offers 1080p Full HD video at 60fps with sensor-based image stabilization and external microphone port, catering to serious hybrid shooters.

Battery Life and Storage

The Sony A57 supports a proprietary rechargeable battery delivering approximately 550 shots per charge under typical conditions, facilitating prolonged shooting.

The ST90’s battery life figures are unspecified but compact cameras of its class generally offer shorter usage durations and require frequent charging or spare batteries.

Both cameras utilize a single memory card slot: the ST90 likely supports standard SD cards; the Sony accepts SD/SDHC/SDXC and Sony’s Memory Stick formats, enhancing storage flexibility.

Connectivity and Workflow Integration

The ST90 lacks any wireless or USB connectivity, complicating image transfers.

The A57 supports Eye-Fi card wireless image transfer, USB 2.0, and HDMI output. These facilitate faster workflows for image review, offloading, and remote shooting.

Pricing and Value Proposition

With an approximate retail of $150, the ST90 is positioned as an entry-level option for casual users seeking simplicity and portability at minimal cost.

The Sony A57, priced near $1000, serves photography enthusiasts desiring significant creative control, superior image quality, and expandability.

Synthetic Summary: Overall Ratings and Genre Performances

Final Verdict: Recommendations Based on Use Case

• Casual compact users and travelers prioritizing portability, low-cost, and instantaneous simplicity
  The Samsung ST90 satisfies fundamental photography needs with easy operation but is limited critically for enthusiasts.

• Aspiring photographers, hobbyists, and professionals requiring substantial control, image quality, and lens flexibility
  The Sony SLT-A57 emerges as a clear winner, justifying its more complex interface and bulk through extensive performance across virtually every photographic discipline.

Gallery: Sample Images Visualizing Differences in Image Quality and Output Characteristics

Samsung ST90 front Samsung ST90 screen back Sony A57 front Sony A57 screen back

Closing Considerations

Choosing between the Samsung ST90 and Sony SLT-A57 translates broadly to a choice between ultracompact minimalism and advanced DSLR-style versatility. While the ST90 occupies a budget space suitable for snapshots and nostalgic convenience, the Sony A57 stands as a powerful tool adaptable to a wide range of demanding photographic scenarios, enriched by its large sensor technology, fast autofocus, and extensive lens options.

The detailed technical breakdowns and tested performance results presented here should empower photographers with varied ambitions to make informed, prudent choices aligning device capabilities with creative objectives.