The Sony A58 replaces two existing models at the entry-level end of its range. Has the consolidation been worth it? We find out in our full Sony A58 review...
Sony A58 review – Features
One of the big updates to the Sony A58 over the A57 is the sensor. Whereas at the A57 sported a 16.1MP Exmor APS HD CMOS sensor, the Sony A58 ultilises an all-new 20.1MP Exmor APS HD CMOS. This is married to an improved BIONZ image processing engine which individually adjusts levels of noise reduction and sharpness in different imaging areas, while the ISO is good for a camera in this class at 100-16,000.
As with all modern Sony DSLRs, the Sony A58 is based around translucent mirror technology (SLT). Out goes the moving mirror and pentaprism found in a typical DSLR, replaced by a fixed, semi-transparent mirror, giving the Alpha 58 its Single Lens Translucent (SLT) status.
If you haven’t come across this before, here’s how SLT works: About two thirds of the light coming through the lens travels through the translucent mirror to the sensor, with the rest bounced up to the AF sensor. The benefit of this is that autofocus can remain in action even when a shot is fired – on a traditional DSLR, the mirror is raised and AF interrupted very briefly when the shutter is triggered. Therefore an SLT’s burst frame rate can also be improved over DSLR rivals.
The absence of a pentaprism on the Sony A58 sees the optical viewfinder replaced with an electronic equivalent. This isn’t always a popular solution as electronic viewfinders (EVF) don’t quite have the same clarity or responsiveness as a traditional optical viewfinder. On the flipside however, you get a real-time display of the shot you’re about to take, ensuring you get the exposure spot-on before you fire the shutter.
The Sony A58’s EVF maintains the same 1.44m dot resolution as the A57, but now uses OLED Tru-Finder technology as opposed to an LCD, reducing overall power consumption, while the viewfinder offers a 100% field-of-view that DSLRs with optical viewfinders at this price point can’t quite match.
Interestingly, the rear screen on the Sony A58 has shrunk in size from the A57, with a 2.7in, 460k-dot display now in place compared to the 3in, 921k-dot screen on the A57. The screen can be pulled out and angled for different shooting heights, but because its hinged differently from that on the A57, doesn’t offer quite the same breadth of movement.
There’s a 15-point AF system, with 3 of those points the more sensitive cross-type variant, while the Sony A58 also benefits from a new Lock-on Autofocus technology for speedier, more accurate subject tracking. Thanks in some part to the SLT technology, the Sony A58 is also capable of shooting at a very fast 8fps (frames per second), though this is using the camera’s dedicated Tele zoom Continuous Advance Priority AE mode. The centre of the image is magnified 2x in this mode (automatically cropping the viewfinder), seeing the resolution drop down to 4.9MP and you’re only able to shoot in JPEG. Again, this is slower than the all-out pace of the A57, which could shoot at up to 12fps in Tele zoom Continuous Advance Priority AE mode, while more tellingly, was also capable of shooting at 10fps at full resolution compared to 5fps for the A58.
The Sony A58 features a new Auto Object Framing technology that builds on the Auto Portrait Framing feature introduced last year. Set to this mode, the A58 judges what’s in the scene – including people, close-up and moving subjects, before tracking, framing and cropping the shot for what Sony say will produce powerful, professionally-framed compositions. Any cropped images go through Sony’s By Pixel Super Resolution technology to be boosted back to the camera’s native resolution, with both the original and re-composed files saved. There is also 15 artistic in-camera Picture Effect treatments that can be applied to the shot.
Sony A58 review – Design
The design of the Sony A58 is pretty much identical to the Sony A57, with a substantial grip with depressions for both middle and ring fingers that provides a comfortable grip, while there’s also a comfy space to rest the thumb at the rear.
While the exterior construction on the Sony A58 is predominantly plastic, it is more than satisfactory for the job, while the rubberised surface round the hand grip and thumb rest provides a decent hold. One area of disappointment though is the lens mount, which is constructed plastic and not metal like the majority of DSLRs – including the A57. If you envisage swapping lenses a fair amount, its worth considering the higher risk of wear that you’ll likely experience with a plastic lens mount as opposed to a metal one.
The body has a reasonable amount on buttons dotted round it, including quick access controls to ISO, exposure compensation, Drive and AF. As well as this, a host of other controls are easily reached with a simple press of the ‘Fn’ button, offering access to a host of other camera settings should you need it.
Navigation of the Sony A658’s interface is carried out via the 4-way D-pad at the rear of the camera, making it pretty straightforward and quick to use.
Sony A58 review – Performance
The Sony A58’s AF performance is good for a camera in this class, with speedy AF acquirement most of the time, only hunting in low-contrast situations. With the 18-55mm lens though, you will experience audible noises as the lens focuses, something that you don’t encounter with its rivals from either Canon and Nikon – such as the Canon EOS 650D or the Nikon D3200 – while the grouping of the AF points has a bias to the centre. If you’re subject’s positioned towards one side of the frame, you’ll have to focus and then recompose.
Whereas rivals predominantly have to rely on slower contrast-detect AF when in Live View or video recording, the Sony A58’s SLT technology means its able to utilize its 15-point phase-detect AF system, delivering the same level of performance via Live View as it does when using the viewfinder.
The electronic viewfinder is less tunnel-like than its peers, while offering 100% coverage that some rivals don’t quite manage as well as a host of shooting info. Its more than fine for composition and focusing in most situations, though if you’re likely to be shooting in high contrast situations a lot, its worth bearing in mind it’s limited dynamic range, resulting in shadow or highlight detail to be lost (though this detail is still capture in the image). So while an EVF has advantages over an optical rival, it does have its pitfalls as well and we’d recommend trying it out before you buy.
The downgrade in screen size and resolution from on the A58 from the A57 is disappointing, while also lagging behind rivals such as the Canon EOS 650D and Nikon D3200. Don’t get us wrong, it’s still more than useable, but doesn’t offer quite the same level of detail and ‘bite’ as the competition.
It can be pulled outwards from the body however, but as mentioned previously, doesn’t offer the same breadth of movement as the A57, allowing it to be pulled outwards for waist-level shooting and downwards if wanting to shoot with the A58 from a raised position.
Being able to rattle off 8fps is handy, but when you consider the reduced resolution and (what may be unwanted) crop to the image, not that spectacular, while it’s only capable of producing a burst of 19 frames. If you want to shoot at full resolution, then at 5fps, only 10 frames in JPEG mode is possible before the camera slows up and slower still at 6 frames when shooting in Raw.
On the whole, the Sony A58 is fairly straightforward to use, thanks to quick access to a host of settings should you need it. One annoyance if you shoot Raw, as with previous Alpha models, is you’re restricted by some of the modes you can use – for instance, its not possible to shoot with any of the Picture Effects if shooting Raw & JPEG – the A58 simple wants JPEG-only. A little frustrating, especially given that rivals are happy to shoot in similar modes, leaving you with an altered JPEG file and an untouched Raw file should you want to revisit the image later.
Sony A58 review – Image Quality
Colour and white balance
The Sony A58’s Auto White Balance performs pretty consistently, delivering pleasing results and natural skin tones under a range of lighting conditions. There’s also a host of presets (Daylight, Shade, Cloudy, Incandescent, Fluorescent (Warm White), Fluorescent (Cool White), Fluorescent (Day White), Fluorescent (Daylight), Flash, Colour Temperature Set, Custom) to dabble with as well, though for most conditions, the AWB copes admirably.
The Sony A58 features a choice of Multi segment, Centre-weighted or Spot metering modes, calculated via the camera’s 1200-zone evaluative metering system. In our tests, the Multi segment metering performed well, exposing well for most scenes, though on occasion in bright situations is did have a slightly tendency to under-expose the shot, requiring a touch of exposure compensation to rectify.
The new 20.1MP sensor is very good, though for best results, we’d recommend using something other than the bundled 18-55mm lens, which doesn’t quite do the sensor justice, but will be fine for general shooting.
In our technical testing and using a pin-sharp Sigma 105mm f/2.8 at a sweet sport of f/5.6, the Sony A58 resolves around an excellent 26lpmm (lines per millimetre) at ISO 100, only tailing of to just over 21plmm at its highest ISO of 16,000.
At the Sony A58’s base ISO of 100, images appear noise free, though subtle signs begin to appear at ISO 800, with a gritty texture appearing in our Raw files at ISO 1600, with luminance and colour noise increasing in presence as the sensitivity is increased to the point where we’d think twice about shooting above ISO 6400. JPEG files at these higher sensitivities attempt to reduce this effect, but the result is mushy looking files with considerable loss of detail.
Ultimately, the Sony A58 can’t quite compete with the competition at higher ISOs, displaying noticeably more image noise than its rivals at identical sensitivities.
Sony A58 review – Verdict
In a tough sector, having a unique selling point is key, and that’s what has made Sony’s SLT stand out from the crowd. But with the Sony A58, its advantages have been diluted considerably. While the AF is solid, the burst rate to back this up and make it a natural choice for action photographers over its rivals has all but disappeared. 5fps at full resolution doesn’t even make it the best in class – you’re better of with the Pentax K-30, that can not only shoot at 6fps, but can sustain that rate for 47 frames. The Tele zoom Continuous Advance Priority AE mode at 8fps might be handy now and again, the reduced resolution and JPEG-only shooting won’t be for everyone.
The increased resolution to 20.1MP sees the Sony A58 resolving greater levels of detail than its siblings, but its compromised at high ISOs, with results just not as useable as its closest rivals. When you factor in the smaller screen and the skimping on a metal lens mount, the A58 seems a step back from the A57 it replaces, but at the same time, it’s also an improvement on the A37 that it also replaces.
The Sony A58 seems to be a muddied compromise between the two cameras it replaces, but it just doesn’t do enough to excel in any one area, and with such stiff competition in the shape of the Canon EOS 650D, Nikon D3200 and Pentax K-30, it’s hard to recommend the A58 above them.
Sample Image Gallery
These are just a small selection of sample images from the Sony A58. For a full selection of images, head on over to the Sony A58 sample image gallery.
Sony’s latest addition to its range of translucent mirror cameras is the Sony A58. Designed to replace the Sony A57 and slot into the Alpha lineup between the Sony A37 and Sony A65, this new model features a brand new Exmor APS-C sized sensor, which boasts a higher 20.1MP resolution than the 16MP output as previously offered by its predecessor.
The Sony A58 teams alongside the sensor Sony’s Bionz image processing engine, which enables the camera to shoot as fast as 8fps in the cameras Tele-zoom Continuous Advance Prority AE mode. The ISO range spans widely from 100-16000, and just like previous Alpha models, the Sony A58 uses the tried and tested SteadyShot INSIDE method of image stabilisation to prevent camera shake and keep handheld shots sharp.
Targeting those who are looking to take the next step up to a more advanced camera, or entry-level DSLR users looking for a replacement camera, one of the most interesting new features on the Sony A58 is its OLED Tru-Finder. This advances on the LCD viewfinder as found within the Sony A57 and is claimed to offer better contrast and rendition of colour. It has a 1.44m-dot resolution – the same as the Sony A57.
Elsewhere, the Sony A58 features a 15-point AF array, with three cross type sensors. This is identical to the AF arrangement as found on the Sony A57. The key difference however is that the Sony A58 now features Lock-On Autofocus, which Sony claim to be faster with more accurate subject tracking.
Another area that has seen development is the Sony A58’s Auto Portrait Framing capabilities. This has now evolved into the more versatile Auto Object Framing – with the idea that it can help achieve better looking images with minimal effort. The Sony A58 judges what is in the scene – one person, two people, even moving objects or macro subjects – tracking, framing and cropping the shot to create powerful, professionally-framed compositions. With Sony’s Pixel Super Resolution Technology, cropped images also preserve the same resolution as the original exposure.
The Picture Effect mode that’s found on the mode dial also allows photographers to pick from a palette of 15 artistic ‘in-camera’ treatments, including Toy Camera, Mono and Partial Colour.
Expected to arrive and be made available to buy by mid-April, the Sony A58 will cost £450 with an 18-55mm kit lens. Sony has also announced that the Sony A58 will be made available as part of a twin lens kit (18-55mm & 55-200mm) for just over £600.
Image Sensor: Exmor APS HD CMOS
Effective pixels: 20.1 megapixels (approx.)
Sensitivity range: ISO 100 – 16000 (25600 with Multi Frame NR)
Autofocus system: 15-point phase detection Live View AF with 3 cross sensors; with AF tracking in Tele-zoom Continuous Advance Priority AE mode
Continuous burst shooting: (max.) 5 fps (8 fps in Tele-zoom Continuous Advance Priority AE mode)
Movie recording: Quick AF Full HD Movie (AVCHD 1920×1080, 50i/25p)
Electronic viewfinder: OLED Tru-Finder with 100% field coverage
LCD: 460k-dot 6.7 cm (2.7-type) with adjustable angle
Image compositing functions: Auto HDR; Hand-held Twilight; Sweep Panorama; Anti Motion Blur; Multi Frame Noise Reduction
Image stabilisation system: SteadyShot INSIDE
Built-in flash: GN 10
Interfaces: HDMI; Multi Interface Shoe; Multi Terminal; Memory Stick Duo / SD card slots
Picture Effect: 11 modes, 15 effects
Dimensions: 128.6 x 95.5 x 77.7 mm (approx.)
Weight (body only) 492g (approx.)
Shooting stamina: Using Tru-Finder: 690 shots, Using LCD: 700 shots