Sony SLT-A99 review

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.