Sony Alpha A77 Digital Camera Review

Kit Lens & Mount

Translucent Mirror

Since there's no dedicated section for "mirror technology," we'll get to it here: The A77's defining feature is its translucent (sometimes called a pellicle) mirror. Like a regular DSLR, this mirror reflects the light coming through the lens up into a phase-detection autofocus system (faster and more accurate than the contrast-detection AF in other cameras). But it also lets light pass straight through to the sensor, so unlike a DSLR, the mirror can stay in place even when the camera exposes a photo.

Basically, the A77 can focus quickly and accurately at all times, even while shooting video. And because the mirror never has to move, the burst shooting rates are incredibly fast.

One disadvantage is that less light reaches the sensor, though this hasn't proven to be a major problem in any of Sony's "single lens translucent" (SLT) cameras so far. SLT cameras also use electronic viewfinders rather than traditional optical viewfinders. It's tough to replace the feel of an OVF—an actual reflection of the image in front of you—but EVFs have come a long way.

Lens

The most common A77 kit includes a 16-50mm (24-75mm equivalent) lens, at a consistent f/2.8 throughout the focal range (SAL 1650). This is the lens we used for our testing. It has a focus mode AF/MF switch on the side, a focus window on the top, and a switch to lock the wide-angle setting in place. This is a brigher, wider lens than most consumer-grade cameras ship with. It's a sturdy unit, with a textured focus ring and zoom ring. It has 16 elements in 13 groups.

The A77 features an A-mount. Carried over from Minolta Alpha (or Maxxum) cameras, A-mount lenses aren't quite as ubiquitous as Canon or Nikon glass, but there's a healthy selection of lenses for a wide variety of purposes. Adapters are available for most common lens mounts as well.

Sensor

The A77 is built around a 24.3 effective megapixel APS-C CMOS sensor. The crop factor is about 1.5x. It's the same size as the chips used in a bunch of system cameras, from consumer-grade Canon, Nikon, and Pentax DSLRs to Sony, Samsung, and Fuji system cameras. This particular sensor is almost certainly the same sensor used in the Sony NEX-7 compact system camera.

Convergence areas of different sensor sizes compared

Viewfinder

The A77 has a 2.4-million pixel OLED electronic viewfinder—the nicest EVF we've ever encountered. Details are sharp, motion is smooth, colors pop, and lag is barely there. It doesn't quite match the feel of a proper optical viewfinder, but it's as close as we've come.

Display(s)

A nice 3-inch, 921,000-pixel articulating LCD complements that excellent EVF. The screen tilts on a hinge and can extend from the body and rotate on an arm. It's versatile enough to frame a self-portrait above or below the camera, and the flexibility enables a bunch of unexpected shooting angles. The screen stays visible in all but direct sunlight, with punchy colors and smooth motion.

Secondary Display

The A77 also has a secondary LCD on the top of the camera. It displays info like shutter speed, aperture, white balance setting, ISO setting, number of shots left, and so on.

Flash

A pop-up flash sits on the crest of the camera. In either auto shooting mode, it can pop up on its own when the scene calls for a flash, but in PASM modes, a manual release on the left side of the crest release it. It's effective to 12 meters at ISO 100 (guide number 12). Controls like red-eye reduction, slow synchro, flash intensity, and flash exposure compensation are available as well.

Connectivity

Like most cameras today, the A77 has mini-HDMI and a USB ports. It also offers a DC input, a microphone input, an external flash hookup, and a remote control port.

All ports are on the left side of the body, concealed under rubberized flaps designed to keep dust and moisture out of the jacks.