Sony Alpha 57 at a glance:

  • 16.1-million-pixel, APS-C-sized CMOS sensor
  • 1.44-million-dot electronic viewfinder
  • ISO 100-16,000 (extended to ISO 25,600)
  • 15-point AF system with three cross-type points
  • 12fps high-speed mode
  • Street price around £700 with 18-55mm kit lens

During the launch presentation for the Alpha 57, Sony revealed it is unlikely to release another DSLR and will instead focus on its single lens translucent (SLT) cameras for the enthusiast market.

This strategy is perhaps an admission that Sony is unlikely to be able to compete successfully with the top DSLR brands in a crowded marketplace, and that developing a different type of system is the best way forward. Sony’s innovative SLT line-up, although still only the second generation, has already established itself as a viable alternative.

An SLT camera uses a fixed translucent mirror, whereas a DSLR features a moving mirror. The fixed mirror of the SLT has advantages over a DSLR in several areas. When compared to its direct DSLR competition, such as the Nikon D5100 and Canon EOS 600D, the Alpha 57 benefits from phase-detection AF for video recording, high-speed capture at 10fps with continuous AF and an uninterrupted live view feed.

The downside to the SLT system is that not all the light coming through the lens reaches the sensor. However, even those concerned with the low-light ability of the SLT system will have been impressed by the performance of SLT cameras.

The Alpha 57 replaces the Alpha 55 in Sony’s current line-up of four SLT models. Sitting between the Alpha 35 and Alpha 65, the Alpha 57 is ideal for those who cannot quite afford the more expensive 24.3-million-pixel Alpha 65, but want more than the entry-level Alpha 35 can offer. On the surface, there are few differences between the Alpha 57 and its predecessor. However, in several areas the features set of the new camera matches other cameras that cost a lot more money.

Features

There are several cameras across the Nikon, Pentax and Sony brands that use a variation of the 16-million-pixel, APS-C CMOS sensor that is found in the Alpha 57. Like its Alpha 55 predecessor, the Alpha 57 uses a 1.44-million-dot LCD electronic viewfinder (EVF), but in this case it has been refined to offer an additional ‘maximum’ magnification setting that further enlarges the view.

A defining difference between the Alpha 57 and the more expensive Alpha 65 is that the Alpha 65 uses Sony’s 2.359-million-dot OLED EVF, which is brighter, crisper and gives greater contrast.

Key shooting modes carried across from the older Alpha 55 include high dynamic range (HDR), 3D sweep panorama, sweep panorama, intelligent auto (iA) and iA+. iA+ includes the continuous shooting and HDR mode options.

The Alpha 57 has 10fps high-speed shooting that can be used with continuous AF and exposure control for approximately 25-frame bursts. A new 12fps burst is available in the tele-zoom continuous advance priority AE mode. To achieve this faster frame rate, a 1.4x magnification is applied, resulting in a 25-frame burst of 8.4-million-pixel, medium-quality JPEGs.

Clear Image Zoom and Auto Portrait Framing are two new shooting modes that make use of Sony’s Pixel Super Resolution Technology. Clear Image Zoom offers up to a 2x zoom from the selected focal length. When used, a full-size 16.1-million-pixel image is saved, unlike with the 2x teleconverter modes found in the Alpha 65 and Alpha 77 that simply crop into the full-size image. Clear Image Zoom works by cropping into the full-resolution image, then interpolating neighbouring pixels, effectively upscaling the image.

Auto Portrait Framing works with face recognition. Once a face has been detected in a scene and the image recorded, a second file is processed that crops the image according to the rule of thirds and in relation to the captured face.

One feature that is lacking in the Alpha 57, but which can be found in the Alpha 65, is GPS. Otherwise, the Alpha 57’s specification is impressive for a camera of its price, and the features on offer should satisfy those who are new to photography.

Build and handling

The body of the Alpha 57 is virtually identical to the Alpha 65, which is larger than the Alpha 55. Both cameras are constructed from a tough polycarbonate shell. The Alpha 57 is well balanced in the hand, with a contoured and textured leather-effect handgrip for a firm hold.

The number of external controls on the Alpha 57 gives it an entry-level feel. There is no top LCD and just a single dial for exposure control, so the AEL button is used to adjust aperture when in manual-exposure mode.

As well as offering PASM control, the shooting-mode dial has several of the specific auto shooting modes, which should aid novice photographers. Also helping out is the ‘?’ button on the rear of the Alpha 57. By default, this is set to access the shooting tip list, which is a wordy beginners’ guide to photography.

The Alpha 57 has some nice touches, though. Many of the buttons, including ISO and AEL, can be customised. The rubber protector over the connection ports is split into four, so the rubber over unused ports can remain in place to keep them protected.

The Alpha 57 also uses the same NP-FM500H battery found in the more expensive SLT models, which has a claimed 50% greater life capacity over the battery used in the entry-level Alpha 35.

The same in-camera menu system is used in all Sony’s SLT models. Through this menu, such useful controls as lens corrections and peaking can be found. Peaking indicates the point of focus in the EVF and on the LCD by outlining the edges of the area in focus, in any one of a choice of colours.

The built-in flash has an output of GN 10m @ ISO 100, which can be adjusted ±2EV, controlled wirelessly, used as a fill-in and set to rear curtain or slow sync.  Handily, the LCD and EVF can display the AF points, an electronic level for side-to-side and front-to-back tilt, as well as exposure preview and exposure settings.

For anyone wanting full control over the camera, they may be a little frustrated by the lack of external buttons, but the Alpha 57 is still quick and easy to operate.

White balance and colour

Image: Skin tones are accurate and sharpness is impressive in this image recorded with the Sony Alpha 57 and 16-50mm f/2.8 lens 

There are six colour modes, comprising standard, vivid, portrait, landscape, sunset and black & white, all of which can be adjusted ±3 for contrast, saturation and sharpness. As with other Sony Alpha cameras, the standard colour mode produces strong but realistic colours.

The saturation can also be tweaked to add punch, but it is easier to change to the vivid setting. I found the auto white balance in daylight to be a little on the cool side, but for most purposes it works well.

The process of creating a custom white balance reading is simple. Take a custom reading by pointing the spot focus at a white area in a scene, then accept the suggested Kelvin temperature. Manual Kelvin adjustment is also available along with nine white balance presets, of which four are varieties of fluorescent light.

In the drive mode menu, white balance bracketing is available over three frames at ‘Hi’ and ‘Lo’ settings.

Metering

All Sony SLTs, including the Alpha 57, use the company’s 1,200-zone metering system, offering multi-segment, centreweighted and spot modes. Spot metering is limited to 15 AF points, all of which are located within the central portion of the frame.

This can make spot metering a little awkward if the subject is off-centre. However, I suspect those interested in the Alpha 57 will generally stick to multi-segment metering, and this mode works effectively, leaning slightly towards underexposing for brighter results.

Autofocus

Image:  Having recorded 10fps sequences all morning using the 70-400mm SSM f/4-5.6 lens, I found the continuous AF works well, with roughly eight out of ten frames, including all in this sequence, having acceptable focus

Like the Alpha 55 and Alpha 65, the Alpha 57 has through-the-lens (TTL) phase-detection AF with 15 points. The points are arranged in three zones, each of which contains one extra-sensitive cross-type point. The number of points is class-leading, and indeed AF is very quick, even in low-contrast light.

Furthermore, offering continuous phase-detection AF during video capture and for high-speed burst modes means the Alpha 57 matches the performance of models that cost a lot more.

There are a number of useful autofocus options and tools available, including subject tracking, which latches onto the object closest to the centre of the frame, and face detection, which works well and stores faces in a register. When these faces are recognised in other scenes, they are given focus priority.

The camera also uses Eye-Start AF, which is a dedicated sensor that turns the EVF on when the camera is held to the eye and also switches on autofocus, so that the camera has already started to focus before the shutter-release button is pressed. Eye-Start can be deactivated, and indeed must be when the continuous AF setting is required.

Dynamic range

The dynamic range of approximately 12.5EV at ISO 100 is standard for a camera at this level. A loss of 1⁄3EV of light because of the fixed translucent mirror should have a more dramatic impact on the dynamic range at higher ISO ratings.

However, although an 8.5EV dynamic range at ISO 3200 is 4 stops less than at ISO 100, this performance is no worse than that of other cameras at this level.

Noise, sensitivity and resolution

The Sony Alpha 57 has a sensitivity range of 71⁄3 EV at ISO 100-16,000, which can be extended to ISO 25,600 in the multi-frame noise-reduction setting.

With virtually the same sensor as cameras such as the Alpha 55, Nikon D7000 and Pentax K-5, it comes as no surprise that the Alpha 57 is capable of resolving a high level of detail. At ISO 100, the camera reaches the 26 marker on our resolution charts in raw and JPEG format.

Levels of luminance noise are inevitably higher than equivalent DSLRs at higher ISO ratings, due to the use of a fixed translucent mirror. However, luminance noise is only really noticeable at ISO 1600, and images are usable at this setting.

Higher levels of noise affect the resolved detail at higher ISO ratings, and for both raw and JPEG files the camera reaches the 24 marker at ISO 3200 and only 20 at ISO 12,800.

These images show 72ppi (100% on a computer screen) sections of images of a resolution chart, captured using the Sigma 105mm f/2.8 macro lens. We show the section of the resolution chart where the camera starts to fail to reproduce the lines separately. The higher the number visible in these images, the better the camera’s detail resolution at the specified sensitivity setting.

LCD, viewfinder and video

A 3in articulated LCD screen is included on the Sony Alpha 57, with a resolution of 921,000 dots. It is movable from a hinge at the bottom of the camera. The screen is clear, with a high-contrast display. Unlike DSLRs, the fixed mirror allows constant exposure of the sensor to light and an uninterrupted use of live view, which in DSLRs is disrupted temporarily during a shutter cycle.

As an LCD unit rather than the OLED type found in the Alpha 65 and Alpha 77, the EVF’s display is not as bright and has less contrast. Compared to others at this price point, however, the Alpha 57’s EVF stands up well. Focus magnify at 4.8x and 9.5x magnification make the viewfinder and EVF even more useful, especially when combined with peaking to indicate the point of focus.

Video files can be recorded in AVCDH2 format at a class-leading 50fps and 25fps.

Verdict

It is a year and a half since the Sony Alpha 55 hit the market, and the Sony Alpha 57 is more of a refresh than a new model. However, there are enough features to separate it from the entry-level Alpha 35, particularly the angled LCD screen, improved EVF and wider ISO range.

The Alpha 57 stands up well against the competition. In several areas its features are class-leading at this price point, and the camera is very capable of producing crisp images with bold colours.

If the choice comes down to the Alpha 57 and Alpha 65, it is definitely worth spending a little extra for the improved sensor and viewfinder of the more expensive model, but there is no denying that at its price point the Alpha 57 provides value for money.