Since Sony dropped its NEX branding and blanketed its compact system camera line with the Alpha brand name, the range has not morphed dramatically, simply divided itself into different schools of thought: those seeking a compact alternative, and those seeking a DSLR alternative.
The Sony A5100, with its nod to compact camera scale and operation, sits firmly within the first camp, for those seeking better quality but compact-like functionality. Higher up the range are the larger full-frame sensor A7 models, which is where the divide happens.
But you're not here to learn about the more complex models. What's enticing about the A5100 is its relatively small scale (considering the large sensor found on board), tilt-angle "selfie screen", E-mount lens range available, and its affordable price point.
Within the interchangeable lens market, however, has Sony's rebranding effort proven enough to keep the A5100 up to scratch with the advancing competition, or does its simplified approach limit potential appeal? We've been shooting for a couple of weeks to see if it's a case of Alpha or Beta.
For the utmost compact-like control the Sony A5100 comes with a 16-50mm power zoom lens option, which is controlled via the zoom toggle around the shutter button, or by using the lens' control ring.
This dual control method is a key component of the camera's lens control, and means it's also compatible with any other electronically-controlled power zoom lenses, both now and into the future. We suspect many buyers will settle on the 16-50mm and not expand further into the available E-mount range, but the option to swap between lenses, including traditional, non-powered optics, is all part of the appeal.
As the 16-50mm lens is collapsible it further keeps the form factor down when the camera is switched off. Switch the camera on and the lens will extend from its stowed position, but given the electronic control of the zoom it can feel more distant in response than a traditional lens barrel. That said, there is the option to rotate the lens ring to zoom, which does respond in double-quick time.
Small scale is key to the A5100's design, with the 109.6mm x 62.8mm frame measuring just 35.7mm deep, most of which is down to the hand grip (which contains the battery). It's a comfortable little camera to hold and use, even if a little finger typically sits underneath the body given the limited height.
However, the lack of immediate on-body controls is a downside in our view. We wouldn't say that's the case for all cameras with a similar design mantra, but in the case of the A5100 it leads to some confusion when trying to access various controls. You'll get used to it, and the d-pad is programmable as a workaround, but it's not the most forward-thinking layout - a problem that's bugged the Sony range since its inaugural NEX release.
As a point-and-shoot user you're unlikely to be exploring the depths of controls, while if you want more from the available manual settings - aperture priority, shutter priority, and so forth - then these are accessible from a press of the centre d-pad button. If you want a more detailed, hands-on experience then the Sony A6000, which is the next rung up the ladder, ought to be more up your street.
READ: Sony Alpha A6000 review
If you're after a pocketable, good looking compact system camera then Sony has got the look and feel of the A5100 right. But its accessibility to controls let it down, which will grate with some prospective buyers.
We've been using the camera out in the icy cold of Montreal, where the bracket-mounted LCD screen's 180-degree orientation came in handy for selfies. A quick tug of the panel sees it pull up and around to face forward for selfies, although a potential issue here comes down to the lens attached - and the widest-angle 16mm setting (that's a 24mm equivalent) from the 16-50mm at an arm's length makes it a little tricky to get more than one face and background into frame. Of course there are plenty of other E-mount lenses on offer which could make this feature all the more viable.
The A5100 is absent of a hotshoe or built-in electronic viewfinder, but rather than see that as a downside, we'll just point you in the direction of the A6000 which caters for those needs. Think carefully about what you want as the Alpha range has both camps covered.
When it comes to autofocus, the ongoing battle for the "world's fastest" system continues, with the A5100 sourcing the same setup as found in the A6000 in this department. We reviewed the latter model last year and found the 179 phase-detection points on the sensor itself, coupled with a 25-area contrast-detection system, made for speedy results. It's the same sentiment in the A5100, even if Sony's quoted figures are a hundredth of a second slower between the two due to differing kit lenses.
Combine the autofocus feature with the touchscreen and it's easy to move a focus point to the desired location, although menu-digging for the autofocus area and autofocus type controls in the first instance meant we rarely bothered. It was a case of centre-point use or auto for us most of the time.
However, autofocus takes a turn for the worse in dim conditions, generalising to a full area with dotted outline rather than honouring a specific focus point, and therefore lacking the precision of some competitors. With Panasonic offering pinpoint AF across its interchangeable lens Lumix line, this is an area where Sony has fallen behind the advancing crowd. It doesn't mean the A5100 fails to focus - that's a rare issue - as we found when snapping the rivets of dim-lit castle ceilings in Stirling, Scotland.
If manual focus is more your thing then the addition of focus peaking can assist in outlining subjects when they are in focus using selectable colours and intensity. The 16-50mm lens ring delivers smooth feedback, although its electronic nature lacks the same precision and feel of a classic analogue lens barrel.
While the autofocus speed effectively mirrors that of the A6000, the A5100 isn't quite as snappy when it comes to reeling off images using its burst mode. But it's still bloomin' quick, capable of shooting up to six frames per second (6fps). Using a super-fast Toshiba UHS-II SD card we were able to snap 24 raw & JPEG Fine shots in succession, which cleared the buffer and were stored on the card in under 20-seconds.
Battery life is a touch better than many typical compact system camera competitors, surviving for longer than the Panasonic Lumix GM5 which we also had on hand. The quoted 400-shots per charge is a bit of a reach if you want to be capturing 1080p video clips, cycling through your snaps and utilising Wi-Fi, but we were shooting to around 250 shots.
Wi-Fi connectivity, for which you'll need to download the Sony PlayMemories app on a compatible smart device, is one of the better setups available for transmitting and sharing shots. This is one area where Sony has forged ahead compared to many of its rivals; connectivity is quick and the app offers direct sharing to the best-known social sites without an intermediary.
The A5100 houses a 24.3-megapixel APS-C sized sensor, which is the norm for many Sony models, and the same as that found in the earlier A5000 model. The sensor is similar but not identical to that found in the better-specified A6000, however, as that utilises a gapless on-chip design. As such, technically speaking, the A6000 has slightly larger "pixels" on the sensor surface with better light-gathering properties and is the better model in the APS-C range.
But in reality the difference is so marginal that many won't notice. Besides, the A5100 still captured good image quality throughout much of its sensitivity range, which is a key point to wanting to purchase this camera in the first instance.
The problem with the Sony, however, is the short flange-back distance from lens rear to sensor means distortion is often rife, particularly at wider-angle settings. You won't necessarily notice it because so much in-camera correction goes on to smooth out JPEG images, but in doing so pixels are stretched and morphed, giving softer outer edges to shots. This process does counteract the wide-angle corner vignetting visible in the raw files, but it's a bit like burning the candle at both ends: either result will raise some questions for particularly discerning snappers.
Given the high resolution there's still scope for ample detail in images though, even if sharpness from the 16-50mm isn't going to rival some of the higher-spec lenses in the range. In good light the lower ISO sensitivities lend well to getting the most available detail, particularly towards the centre of the image.
Sony A5100 review - sample image at ISO 500 - click for full size JPEG crop
At the ISO 100-200 entry settings there's no image noise to worry about, with clear results, and no unwanted fringes of colour - whether colour noise or prominent chromatic aberrations - within images.
At the opposite end of the scale - and ISO 3200 is the default cap for the Auto ISO setting, despite a bonkers-high ISO 25,600 option - the in-camera processing dials out a lot of detail in an attempt to remove the grain and some visible image noise. While it succeeds it does soften the image, often to excess.
An ISO 3200 shot of the throne room at Stirling castle, Scotland, for example, shows detail in the raw file, albeit smattered with a covering of grain, which is smoothed out in the JPEG file. It works for certain areas of the image, such as the walls, but details such as the emblem on the throne legs, lose critical clarity. We'd prefer to see more subtle processing.
In the middle of the sensitivity range, the A5100 delivers a more balanced output which bodes well. We'd happily shoot at ISO 800 with few qualms, meaning some low-light shooting, with the right lens attached, is easily within reach. Watching Canada vs USA in the IIHF World Junior Championship saw the players captured in the ice hockey rink from afar, frozen in motion at ISO 500.
Overall the A5100 produces good quality images, despite distortion correction and excessive JPEG processing costing it from being the very best compact system camera out there. Match it up with a decent lens, avoid the widest-angles, shoot raw and prepare to be happy with the resolute results from this small camera.
The Sony A5100 won't appeal to all as it's sometimes fussy to use given its lack of control dials. If that's what you're after then look to the Sony A6000 which caters for such needs, along with the addition of a viewfinder and hotshoe which the A5100 lacks.
Whether you venture into buying additional E-mount lenses in the future or not almost doesn't matter with a camera such as this. And while it can't claim to be the smallest, nor offer the best-in-class image quality or low-light autofocus ability, as a balanced all-rounder there's a lot to take away - including more change in your back pocket than many of its competitors would leave you with.
The A5100 is aimed at an audience wanting point-and-shoot simplicity - and perhaps the odd selfie - but better image quality than a high-end compact can offer. Despite rife competition, this Sony still manages to offer ample appeal despite a couple of bumps in the road along the way.
£475 (with 16-50mm lens)