Sony Alpha A99 review
It's been over three years since Sony last launched a full-frame camera, and the A900 and A850 were discontinued long before a successor were announced. That successor is finally here though, in the form of the Sony Alpha SLT-A99, and with a raft of new technologies it looks like Sony is fully committed to the format.
The curvy magnesium alloy body is extremely comfortable to hold, and we can't fault the layout of the controls. It's also weather sealed – something we were able to test extensively during the official launch in Iceland. It carried on snapping through rain, sea spray, geyser eruptions and sulphur clouds. It's a credit to the camera's controls that we were able to use it with confidence in these conditions after such a short time.
Sony has paid particular attention to autofocus speed and accuracy – something that its SLT cameras already have a head start with, as their autofocus sensors are constantly active rather than being interrupted when the mirror flips up to capture an image. However, the headline 10fps performance is only in a speed-priority scene preset, which crops the sensor to 4.6-megapixels, limits manual control and disables raw mode.
Full-frame capture is fast, too, at 6fps, but unlike the Canon EOS 5D Mark III, the A99 can't sustain this speed indefinitely. In our test it slowed to 2.3fps after 13 frames for JPEGs, and to 0.9fps after 11 frames for RAW. This was testing with a UHS-I SD card rated at 95MB/s, although the fast ISO speeds we were forced to used may have slowed the camera a little, as noise-reduction processing was working harder.
While the Canon 5D Mark III and Nikon D800 use their metering sensors to enable tracking autofocus, the A99 does this with the help of 102 phase-detect autofocus points integrated onto the sensor. It's a clever idea and the system appeared to work well, but based on initial tests we suspect that the D800's 3D Tracking mode still has a slight advantage.
The main autofocus sensor has 19 points, 11 of which are cross type. Compared to other full-frame cameras, this puts it closer to the recently announced Canon EOS 6D (11 points) and Nikon D600 (39 points) than the more upmarket Canon EOS 5D Mark III (61 points) and Nikon D800 (51 points). The number of autofocus points is only one ingredient for a successful autofocus system, but it's an important one. The A99's 19 points are densely packed in the centre of the frame – we'd prefer them to be more spaced out.
One of the simplest but best new features is an AF Range button. It's well place to find by touch when using the viewfinder, and having pressed it, the maximum and minimum focusing distances can be reined in using the dual command dials. This proved to be extremely useful to avoid the autofocus system being distracted by subjects in the foreground or background – including shooting through rain-soaked car windows. It's extremely quick to use, with informative on-screen graphics. As with articulated screens, this is the kind of feature that, once you're used to it, it's hard to imagine living without.
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