Sony SLT-A99 review

Price above is for the A99 body only, no kits available at present, we tested with a 24-70mm f/2.8 Carl Zeiss Vario-Sonnar T* lens, costing £1,449 inc VAT

You wait for ages for a new full-frame SLR and then seven turn up at once. Canon and Nikon refreshed their full-frame ranges in 2012, each releasing three new models priced at around £1,500, £2,500 and £5,000. Sony full-frame cameras have been conspicuously absent since the A900 and A850 were discontinued in 2011, but the A99 marks a bold re-entry.

It’s priced to compete with the Nikon D800 and the Canon EOS 5D Mark III (£2,400). Sony is making a bold statement by pitching it against such esteemed rivals rather than their cheaper full-frame siblings, but the A99 has the specs to back it up. The substantial magnesium alloy body feels like a premium piece of kit and is covered with buttons and dials. There are dual SDXC card slots, a PC sync socket for external flash triggering, microphone and headphone sockets plus built-in GPS.

This SLT may differ significantly from other full-frame cameras, but it’s still entering a very competitive market

Then there are the features that distinguish Sony’s SLT cameras from conventional SLRs. The translucent mirror technology means there’s an electronic viewfinder (EVF) rather than an optical one. SLR purists may baulk but we find it impossible to be downbeat about this particular EVF. With its 1024×768 (2.4 million dot) resolution and a 0.71x magnification, it’s just as big and detailed to our eyes as a full-frame SLR’s optical viewfinder. While an optical viewfinder will give a truer representation of the scene in front of you, an EVF gives a more accurate preview of the photo you’re about to take – complete with exposure and white balance settings and clipped highlights and shadows. It can also display lots of other information including a histogram and digital spirit level, although not at the same time.

SLT technology also means that the main phase-detect autofocus system is available when composing shots using the LCD screen. Sony takes full advantage of this with a pin-sharp 3in screen that pivots at three points to cater for every conceivable viewing angle. It’s the same screen and viewfinder that we saw on the Sony A77, and they’re just as impressive here. In fact, the A99 is the only full-frame camera to include an articulated screen.

An articulated screen on a full-frame camera is a rarity

There’s one major downside to SLT, though. It means the sensor is constantly active, and in a full-frame camera that takes a heavy toll on battery life. It’s quoted as 410 shots when using the viewfinder, and 500 shots with the LCD screen. Additional batteries are £35 including VAT each.

CONTROLS AND VIDEO

The controls are very similar to the A77’s, but there are a couple of notable differences. Rather than a focus mode dial below the lens release button, there’s a button and dial that Sony has named the Silent Multi-controller. A quick press of the button brings up autofocus mode options on-screen, which are cycled through with the dial. However, hold the button down and the dial can be reassigned to focus area, focus point, exposure compensation, ISO speed or metering mode.

Three more options are added when recording video: microphone level, shutter speed and aperture. This is where the silent part comes in. Whereas the other buttons and dials are liable to pepper the soundtrack with audible clicks, the Silent Multi-controller is genuinely silent. It’s extremely useful to be able to adjust the exposure while recording without spoiling the soundtrack. However, exposure adjustments were a little jarring on the eyes. Changes were instantaneous, giving a stepped appearance to the exposure. It’s disappointing considering that exposure adjustments are much smoother when videoing with automatic exposure settings.

Another perk of the translucent mirror is that phase-detect autofocus is available during video capture. Focus adjustments weren’t exactly silky smooth but they were quick and accurate, and fine for casual use. Video autofocus isn’t available in priority and manual exposure modes, but that’s not a disaster. Most people who want the former will be happy with the latter, especially as manual focus is so well catered for. The large, high-resolution EVF makes a huge difference here, and so does the focus peaking mode that highlights sharply focused parts of the frame. There’s also a button to engage a momentary 5.9x or 11.7x digital magnify function – just the thing for checking manual focus. For some reason it’s not available when the video mode is selected on the mode dial, though, not even before recording commences.

Keen videographers will appreciate the wide range of frame rates from 24p up to 60p, the microphone and headphone sockets and the optional XLR mic input module (XLR-A1M) that sits on the accessory shoe. The module comes with the ECM-XM1 stereo microphone and so costs around £600 – it’s annoying that it’s not available to buy separately.

Videographers might not be too impressed by the detail levels in 1080p clips, though. They looked a little vague when viewed in isolation, and direct comparisons with the Canon EOS 5D Mark III, Nikon D800 and Panasonic Lumix DMC-GH3 put it in last place for video detail.

These crops from 1080p video frames show how these four cameras handle detail in videos. The Panasonic GH3 scores a clear first place here, while the Sony A99 trails in last place (click to enlarge)

AUTOFOCUS

The other notable change compared to the A77’s controls is a button labelled AF Range. Pressing it reveals a bar across the bottom of the screen (or viewfinder), and turning the front and rear command dials limits the range of the autofocus. It’s extremely useful for shooting subjects that are partially obscured. It can also avoid focus hunting in tricky shooting conditions. We found it easy to adjust and the benefits were clear, especially when using a wide focus area for unpredictable subjects.

Sadly, there’s not much else we can praise about the A99’s autofocus system. There are 19 autofocus points, 11 of which are cross type. That doesn’t compare well with the Canon 5D Mark III’s 61 points or the Nikon D800’s 51 points. A bigger concern is how these 19 points are bunched together in a small central part of the frame. It’s the same problem that we saw on the Canon EOS 6D and Nikon D600, and it’s particularly disappointing to find it in this much pricier camera.

The 19 autofocus points (represented by squares on the screen) only cover a small area in the centre of the frame. The 109 on-sensor points (smaller crosses) cover a wider area but they’re only there to assist the main 19-point system

The A99 tries to make up some ground with a secondary array of 109 phase-detect points built directly into the main imaging sensor. It’s an intriguing idea, but as with other cameras we’ve seen with on-sensor phase-detect points, the benefits weren’t entirely obvious. The screen showed these points lighting up when focus was achieved, but there wasn’t much evidence of the camera using them to inform the autofocus system. Accurate autofocus was only ever achieved when one of the 19 primary autofocus points locked onto a subject, so at best, the secondary points made that process a little quicker. The secondary points are compatible with only a small number of lenses too. For us, the bottom line is that this is an underspecified autofocus system for the price.

PERFORMANCE AND IMAGE QUALITY

The translucent mirror means the imaging and autofocus sensors operate simultaneously. In cheaper Sony SLT cameras, this has delivered seriously fast continuous performance with full-time autofocus – the A77 managed 12fps. The A99 couldn’t achieve half that, delivering 5.9fps in our tests, slowing to 4.3fps after 24 frames. Raw performance slowed more dramatically, falling to 1.2fps after 10 frames (testing with a 94MB/s SDHC card). The Canon 5D Mark III delivered 6fps for JPEGs with no slowdowns in our tests, while its raw performance started at 6fps and fell to 2.5fps after 19 frames.

The A99’s 5.9fps result puts it ahead of cheaper full-frame cameras, though. It also offers faster modes using a cropped area of its sensor – 8fps for 10-megapixel photos, and 10fps for 4.5 megapixels. However, only the slowest 3fps, 24-megapixel mode provides a live view display. The faster modes show a sequence of captured photos, which made tracking moving subjects extremely difficult.

It’s always nice to end on a positive, and the A99’s image quality lets us do exactly that. The 24-megapixel resolution is, in our view, perfect for a full-frame camera, delivering plenty of detail and seriously low noise levels. There was a slight increase in noise because of the translucent mirror, which stops some of the light from reaching the imaging sensor. However, comparing the A99’s output with the Nikon D600, which uses the same sensor and a conventional moving mirror, there wasn’t much to choose between them.

Taking the A99 out of the studio and into the wild, its JPEGs were simply stunning. Testing with a 24-70mm f/2.8 Carl Zeiss Vario-Sonnar T* lens (a snip at £1,449 inc VAT) certainly helped. Subtle details were rendered with precision, without any hint of digital artefacts. The metering coped well in tricky conditions, amply supported by dynamic range optimisation to lift gloomy shadows. Noise was barely perceptible at ISO 1600, and it produced print-worthy JPEGs at ISO 12800.

The skin and hair in this shot are immaculately rendered

This ISO 800 shot is virtually indistinguishable from the A99’s output at ISO 100

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There’s lots of detail and remarkably little graininess at ISO 6400

CONCLUSION

It’s hard to give an overall rating for the A99. We loved using it, and the small autofocus coverage was rarely a big nuisance. When we got the photos back home for inspection, we loved this camera even more.

However, while the heart is willing, we can’t avoid making comparisons with other full-frame SLRs. We’re not convinced that Sony has done enough to justify pricing the A99 above the Canon 6D and Nikon D600. A 4K video mode or 10fps full-frame photo capture would have clinched it. As it stands, this is a seriously impressive full-frame camera but it’s not our favourite.