The A99's external control layout is virtually identical to that found on its APS-C sibling, the SLT-A77, with little in the way of design or ergonomics that harkens back to Sony's first full frame SLR, the A900. As you'd expect from a top-tier model, the A99 has a magnesium alloy body with dust and moisture resistant sealing. What's more noteworthy, is that such a solid construction weighs in at only 812g, making it noticeably lighter than both the Nikon D800 and Canon EOS 5D Mark III. It must be said though that pairing the A99 with top-notch Zeiss glass like the Sony 24-70mm F2.8 ZA SSM Carl Zeiss Vario-Sonnar T* lens will effectively negate any weight savings against rival combinations from Nikon And Canon.

Photographers who demand immediate access to highly personalized shooting options will appreciate the high degree of customization possible with the A99's numerous control points. No fewer than five external buttons can be assigned to any of 31 separate functions. You can also choose to disable the movie record button when the camera is set to a stills shooting mode. Outside of our wish for a more efficient way to navigate the menu system, we find little to slow you down from an operational standpoint.

The A99 features the same 1.23m dot RGBW LCD screen found in the Cyber-shot DSC-RX1 and RX100, although here it is mated with a dual-hinge articulated design that allows for a a number of useful - if origami-like - configurations using the camera in awkward viewing positions. The camera's lockable mode dial gives users quick and easy access to shooting modes without fear of accidental operation. An eye sensor located just beneath the viewfinder automatically switches between the EVF and rear display panel, though you can opt to switch between the two manually if you prefer. With no fewer than five separate display overlays available in the electronic viewfinder (and six on the rear panel), we suspect that most users who refer to the A99's top plate LCD will do so out of habit rather than necessity.

Overall operation and handling

The A99 largely follows the tried and true path of a contemporary high-end DSLR, with a deep, comfortable hand grip, one-button access to video recording and shooting parameters along with front and rear dials to navigate among camera settings and exposure options. The standout spec compared to its full frame rivals, of course, is the inclusion of an electronic viewfinder. The 2.4M dot OLED screen used here was first seen in the A77 and NEX-7 cameras. Its comprehensive integration means that you can use it in exactly the same manner as the rear LCD. In addition to viewing accurate image previews that reflect exposure, white balance and color mode selections, you can navigate the Function menu and menu system with the camera held at eye level.

Studio photographers who use flash will appreciate the ability to toggle exposure simulation on and off via the 'Live View Display Setting Effect' option. This allows you to compose a dimly lit scene (to be illuminated at the time of exposure via flash) through the finder or rear LCD with the camera 'gaining up' to provide a bright preview image.

In terms of design and UI, the A99 is almost identical to the A77. Exposure settings are changed using front and rear control dials, and both the EVF and rear LCD can provide a live view feed in still and movie modes as well as image review during playback.
The 3.0-inch rear LCD panel is mounted on a dual hinge that allows for rotation of 180 degrees both downward and clockwise, a tilt of 140 degrees and a 90 degree rotation counterclockwise.
Alongside the lens throat, in place of the A900's AF switch, the A99 introduces a customizable silent control dial with a central confirmation button.

The button can be configured independently for stills and movie modes.

In addition to its front and rear dials, the A99 introduces a new 'silent controller' (shown above) on the front of the camera below the lens release. Intended primarily as a way to adjust camera settings while recording video without introducing audible button clicks, its function can be defined separately for stills mode (and changed simply by holding the central button down). The options include changing focus mode, which recreates the function of the control that Sony usually puts in this position.

VG-C99AM Battery Grip

The optional VG-C99AM grip provides not only a vertical-oriented set of controls but offers greatly extended shooting capacity with the ability to install two additional NP-FM500H batteries for use alongside the existing one in the camera body. This also gives the useful advantage of changing the batteries in the grip without powering off the camera.

The VG-C99AM grip triples the power options of the A99, allowing for two additional NP-FM500H batteries to be used in succession along with the one housed inside the camera body. As we've become accustomed to, Sony adds a comprehensive set of duplicate vertical controls, including a shutter release, front/rear dials, five control buttons and a joystick.

As with the A77, Sony adds a wide array of external controls to the optional grip for the A99. And as we saw in that earlier SLT model, the exposure compensation button again occupies the same relative position as the AF/MF button on the main body, which may take some getting used to when adjusting settings by feel in portrait orientation. And while no one can accuse Sony of providing too few controls, one nice feature would be the ability to customize the vertical grip's buttons.

Auto ISO in Manual Mode

The availability of Auto ISO in Manual exposure is something we've seen an increasing number of our readers ask about. Auto exposure while you're in manual mode may seem like an odd request, but this is something we've seen from Pentax, who makes its use clearer by separating this combination out as a dedicated 'TAv' shutter-and-aperture-priority mode. To make it useful, unless the camera somehow has perfect exposure in all conditions, you really need to also have access to exposure compensation in manual mode - which is an unusual combination to offer. The good news for people wanting to shoot this way is that A99 does indeed offer exposure compensation and Auto ISO in manual exposure mode. With ISO set to a fixed sensitivity, however, the exposure compensation button is inactive. Should you press it, the A99 helpfully gives you a warning that ISO must first be set to Auto.

Specific issues

Our only complaints in using the A99 out in the real world center around fairly specific shooting situations. For all of the advantages of an EVF in terms of information display and exposure preview, the limitation that remains is that live view is unavailable when shooting at the camera's fastest frame rates. In these instances the viewfinder does not black out, but what you see is not a live preview, but instead the succession of images you have just captured. Panning while tracking fast moving subjects, therefore, will prove difficult to do with precise framing accuracy.

The joystick on the rear of the camera protrudes rather noticeably from the camera body, extending beyond the LCD panel. As a consequence, we sometimes found ourselves inadvertently moving the AF point around, for example when shooting with the camera in portrait orientation while wearing a hat.