Sony SLT-A99: Initial review
Posted by Dave in Reviews on Nov 14, 2012 comments and reactions


At the start of September I received an email from GPP asking me if I'd be interested in being involved with the launch of a couple of Sony's new cameras, to coincide with my upcoming visit to Dubai for their Fotoweekend event: the SLT-A99, their new full frame pro-spec camera, and the NEX-5. I wasn't especially interested in the NEX-5 – it's a good little camera, but not one that I'd use – but the SLT-A99 looked more promising.

If you're not familiar with Sony's SLT cameras the basic difference between them and a DSLR is that the mirror doesn't move, hence Single Lens Translucent rather than Single Lens Reflex. With a DSLR the mirror flips out of the way before you take the shot, with an SLT the majority of the light is fed continuously to the sensor, with a portion being routed to the main AF module via the mirror. In theory this means that you're losing around 0.3EV to 0.5EV from the outset, but in practice this loss of light seems to have little or no effect on the quality of the image.

The deal was that I'd get to keep the camera and a couple of lenses in exchange for spending some time shooting in the UK followed by two days intensive shooting in Dubai. Those images would be used to create a range of A0 prints, a photo book, and so on. I was also asked to give a 10 minute presentation at the press conference and another public talk on my experiences of shooting in Dubai as part of GPP's Fotoweekend event.

So, an intensive schedule (I was shooting on the 2nd and 3rd of November and the press conference was on the 6th), a fair amount of pressure (the images needed to be good), but I'd get to keep the camera and two lenses: the Zeiss 24-70mm F2.8 ZA SSM Vario-Sonnar® T* and the Zeiss 85mm F1.4 ZA Planar T*, both of which are great pieces of glass.

Was I delighted? Initially, no. Let me explain why ...

My impression of Sony, prior to working with the A99, is that they're a company who produce cutting-edge and innovative technology – projectors, TVs, amateur cameras, and so on – but I wouldn't have seriously considered any of their SLT cameras for professional use. In fact, until Sony contacted me I knew virtually nothing about the A99 or any of their other SLT cameras. I own a Canon 5D Mark II (which I love), a 5D, a 1Ds Mark II, four Canon Speedlites, and nine Canon lenses (five of which are L lenses), and if I was planning on buying any new kit it would probably be the 5D Mark III or the 1D X. So why would I be interested in the A99?

Put another way: when a student asks me 'which camera should I buy?', especially if they're interested in pursuing a career in photography, I invariably say something along the lines of 'get the best you can afford, but make sure you budget for some decent lenses too as there's no point in spending a whole load of money of a great camera and then using inferior glass. So check out the Canon (insert suitable model depending on budget) or Nikon (whatever), both are great cameras'.

I wouldn't have suggested buying a Sony because a) all the prior cameras in the SLT range were based around an APS sensor (which is OK for some forms of photography, but the quality will never match that of a full-frame sensor), b) I knew relatively little about them, c) their lens range is quite a bit smaller than Canon and Nikon, and d) the range of 3rd party accessories is more limited.

From now on though, I will be suggesting the SLT range, particularly the A99.

So what changed my mind?

image quality

First and foremost, the SLT-A99 produces truly great images. I've been shooting with it for a few weeks now and in pretty much every respect the images are noticeably better than those I've shot with my 5D Mark II: greater detail, larger dynamic range, and better high ISO performance.

Here's a couple of examples. The first shot in each pair is a 730px wide version of the original high res' (post-processed) file, the second a 100% crop. Both RAW files were converted with Camera Raw, with default input sharpening. No output sharpening was applied to the cropped images.

Sheik Zayed Road, Dubai: Sony SLT-A99 & 16-35mm F2.8 ZA SSM Vario-Sonnar® T* @ 18mm. 25s, f/9, ISO 100

100% crop. No output sharpening

Textile Souk, Dubai: Sony SLT-A99 & Zeiss 85mm F1.4 ZA Planar T*. 1/100s, f/7.1, ISO 640

100% crop. No output sharpening

As I hope you'll agree, the 100% crops indicate that this is a camera that can produce very sharp images, and while both were shot with good lens, the clarity of the images is at least partly due to the 24.3MP Exmor sensor. I haven't seen any objective tests yet but it's worth pointing out that this is probably the same sensor that Nikon are using in their D600 (see this page for confirmation).

Now, it may be the case that the sensor in the D600 was produced to slightly different specifications but it doesn't seem likely that Sony would produce an inferior 24MP sensor for their own flagship camera. As such I think it's fair to assume that the IQ of the A99 is likely to be broadly comparable to the D600. If so, and if DxOMark are to be believed, the A99 should stack up very favourably against its nearest rivals: the Nikon D800 and the Canon 5D Mark III.

Nikon D600, versus Canon 5D Mark III, versus Nikon D800

And if you take a look at the scores for the Nikon D4, D3X, and the Canon 1Ds Mark III then the A99 starts to look very good indeed.

In short then the sensor in the A99 is truly excellent.

In a follow-up post I'll write more about its dynamic range and how it performs at higher ISO – I want to shoot some comparison images with my 5D II before I make any definitive statements – but my initial impressions are that it has at least two more stops of dynamic range than my 5D II and is clearly superior at higher ISOs. For the time being, trust me, this is a class leading sensor.

key features

OK, so the IQ's great, but what other features does the A99 have? I'm going to talk about a few of them in more detail below, but here's a quick summary.

  • 24MP full-frame CMOS Sensor with on-chip phase detection AF
  • Dual AF system with 19 focus points plus an extra 102 AF points on the sensor
  • Fixed-mirror design SLT
  • 2.4M dot OLED EVF (electronic viewfinder)
  • Focus peaking
  • 14-bit Raw output
  • ISO 100-25,600
  • Up to 6 frames-per-second continuous shooting with AF (10 in burst mode)
  • ISO-compatible flash hotshoe with 'multi interface' expansion connector
  • Pull-out three-hinge tilt/swivel 1.23m dot RGBW LCD screen
  • Top panel LCD
  • Microphone and headphone sockets
  • Built-in GPS
  • AF Micro Adjust
  • Shutter rated for 200K release cycles
  • Rugged, lightest in class, weatherproof body
  • 100% OLED viewfinder with 2,360K resolution (auto enlarges with crop lenses)
  • Dual SD slots
  • GPS
  • Full HD 50p (or 60p) video
  • Silent, customisable control wheel (especially useful for video)
  • Customisable button layout

In short then, this is a well-specified camera with a broad range of features, as you would expect for one that's targeted at the pro and high-end amateur market. I'm not going to go through all of these, but there are a few I want to draw special attention to, particularly those that are related to the EVF (electronic viewfinder), but there are a few other features that I'd like to mention first.

focus modes

The A99 has a variety of autofocus modes, more of which below, all of which are driven by a dual AF system: a dedicated 19 point AF phase detection module (with 11 cross point sensors), which is fed by light from the mirror, and a secondary 102 point phase detection system built into the sensor, as illustrated by the image to the right.

The A99 has a range of standard autofocus modes (single shot, continuous, face detection, etc) but also has AF-D, a new system that utilises both focus modules to (according to Sony) improve focus speed and accuracy, particularly in terms of tracking an object through three dimensional space. I haven't had the chance to test this in any great detail – and coming from the 5D Mark II pretty much ANY new autofocus system is an improvement – but I can confirm that it's fast and accurate.

onboard image stabilisation

Unlike Canon and Nikon, where image stabilisation is built into some of their lenses, Sony have opted to incorporate it into the camera: the sensor moves, not a the lens elements. The major advantage is that all the lenses you use can be image stabilised, and it works very well. Take a look at the following example and you'll see what I mean. It was shot with the 85 f/1.4 at 1/4s, i.e. just over 4 stops below a sensible hand-holding speed of 1/80s.

The Vista Bar, Dubai: Sony SLT-A99 & Zeiss 85mm F1.4 ZA Planar T*. 1/4s, f/5.6, ISO 6400

100% crop. No output sharpening

In practice I found that I could get two stops of IS pretty much 100% of the time. At three stops somewhere around 90% were sharp, and at four stops about 30-40% of the images were sharply focussed. In short then it's a pretty impressive system. The only negative I found is that you need to delve into the menus to turn it on and off, which isn't a deal breaker, but is a bit annoying when you're switching between hand-holding and shooting on a tripod.

lcd panel

Articulating LCD panels are nothing new but it's rare to see them attached to high end cameras, particularly those that are aimed at the pro market, despite the fact they're extremely useful.

For example, the following image was shot from about an inch above the ground, hence the strong reflection in the wet sand. With my 5D Mark II I would have shot this either laying in the sand, and getting wet, using Liveview, while craning my neck to see the screen, or by using a bubble level attached to the hotshoe to keep the camera level while guesstimating the composition. I would have probably got the shot, or something similar, but the process wouldn't have been very fluid.

With the LCD panel on the A99 though, things were a lot easier. Flip it out, position the camera, compose, and shoot.

Image © 2012 Simran Puri

And here's the final image ...

ergonomics and design

One of Sony's marketing points for the A99 is that it's lightest in its class, by around 100g or thereabouts, but by the time you've stuck a decent piece of glass on the front – for example the Zeiss 24-70mm F2.8 ZA SSM Vario-Sonnar® T* (which weighs almost 1kg) – the weight saving isn't really an issue. In fact, I think I would probably prefer it if it weighed a bit more, not because it feels insubstantial, but because it would be slightly better balanced. On the whole though it's a comfortable camera to use, and one that feels rugged and well designed.

One of my favourite design features is that many of the buttons are customisable. For example, the AEL button can be reprogrammed for back-button autofocus, the silent control wheel can be used to switch focus modes, and so on. There's also an additional custom button that can be set to control pretty much any of the camera's features. This isn't a huge selling point, and I haven't felt the need to reprogram and of the key buttons, but it does demonstrate a commitment to usability that many manufacturers ignore.

electronic viewfinder (evf)

The EVF is the one feature of the A99 that I didn't expect to like – the whole idea of it just feels wrong – but, for a variety of reasons that I'll discuss below, it's turned out to be one of my favourite features.

The major advantage of an EVF versus an optical viewfinder is that you see exactly what the camera sees: the image is fed directly from the sensor to the 2.4MP EVF. This has a range of major benefits.

First, the image in the viewfinder is a 100% of the scene, so no more guessing what's at the edge of the frame. If you change the white balance setting you can see the change as you compose your shot. If you preview the depth of field you can do so without the viewfinder dimming because you closed down the aperture.

What I like best about the EVF is that once you've taken your shot the preview appears in the viewfinder, either as a full-frame shot or with the histogram and shooting details. This is extremely useful as it means you don't need to constantly move the camera from your eye to check the exposure using the LCD panel. That said, I did find this a bit difficult to get used to – lifting the camera to your eye and seeing the previous shot is a bit disconcerting at first – but having got used to it I find it a much better way of working.

focus peaking

Focus peaking isn't new, but it is the first time that it's been available in a pro-spec body. If you're not familiar with it, it's a focus aid which uses the autofocus system to place a (red or yellow) outline around areas of the image that are in focus. This is especially useful when you switch to manual focus. For example, rather than trying to guess what's in focus (as you need to do when using an OVF), or switching to Liveview to zoom in and check, you get immediate feedback in the EVF about what's in focus and what's not. In practice this is a) very easy to use, and b) very accurate.

For example, you can focus on the catchlight in a subjects eys at f/1.4 and know that you're nailed the shot, something that's almost impossible using an OVF. It's also a much better solution than using autofocus, which will often lock onto the eyebrow or some other nearby feature rather than your subject's eye.


So far then, so good, I'm sold on this camera. But there are some issues to bear in mind if you're thinking of buying into the Sony system. First, while Sony produce some fantastic lenses (particularly their Zeiss-badged glass), their range isn't as comprehensive as Canon and Nikon's. So, no tilt-shift lenses, a limited range of fast telephotos, and so on. For me, this isn't an issue – I'm happy with a handful of fast primes, a 16-35, 24-70 and 70-200 – and if I ever do need to use a more exotic lens for an assignment I'll rent one and use it with my 5D Mark II. Not a huge issue then, but one to bear in mind.

It's also worth noting that there's also a comparative lack of 3rd party accessories for the Sony system. For example, Pocket Wizard produce TTL triggers for Canon and Nikon, but not for Sony. If the A99 is a success, and Sony do make inroads into the pro market then I guess that this will change, but, for the time being, bear in mind that your choices regarding third party peripherals and other kit will be more limited.

Update (17th November): I've just been reading an article on Frank Doorhof's blog (who was also shooting with the A99 out in Dubai) about the Phottix flash triggers. These are wireless triggers that allow both manual and TTL control of your remote flash units. The good news is that these are now going to be available for Sony systems too.

The final negative point, and one that seems to get picked up by most reviewers, is battery life: the A99 eats batteries. Typically I've found that I get between 400 and 500 shots, which is way less than I'd expect when shooting with my 5D Mark II. That said, it's a) not unexpected (the EVF uses quite a bit of power), and b) carrying around a couple of spare batteries isn't a huge issue.

Other than the above though there's really not much else I can fault.


As I guess you've already worked out, I'm seriously impressed with the SLT-A99. The image quality is superb, it has a great range of features, and no real negatives, at least none that have any major impact on my style/type of photography. As such I have no problem recommending this camera.

Would I buy one if Sony hadn't given it to me? Yes, probably, though the effort, time and expense involved in selling my Canon gear to fund it would have been a major pain. And I guess that's the major problem that Sony will face in marketing this camera: anyone who's seriously considering upgrading to a pro-spec body probably already has at least one Nikon or Canon body and a bunch of lenses, so making the switch is a major commitment.

For anyone just starting out though – maybe you have a Canon 600D and kit lens, or the Nikon equivalent – switching to Sony would make a lot more sense. I can't predict the future but, for now, I think Sony pretty much nailed it with the A99.

At some point soon I'll post a more detailed article on the A99's dynamic range and low light ability. In the meanwhile, if there's any other feature you'd like me to focus on, let me know in the comments below. Likewise, if you'd like more detail about anything I discussed above, or have any other questions, let me know.

Join the discussion below ...