Ten frames per second with continuously active AF is no mean feat, especially in a camera costing £700. Whether it is worth the loss of the optical viewfinder is another matter
It goes without saying that the defining feature in the Alpha 55 is its use of translucent mirror technology. This has an effect on much of the Alpha 55’s functionality, including the viewfinder, autofocus and frame rate.
Although this technology has been used in SLRs in the past, it has proved unpopular because the light is split between the imaging plane and the viewfinder. This leaves the viewfinder significantly darker and consequently difficult to use. Sony has got round this by using an electronic viewfinder (EVF). Until now, EVFs have not been used in high-end/more advanced cameras because the technology was not up to scratch, particularly in terms of resolution.
However, while cameras such as the Panasonic Lumix DMC-G2 have shown that EVFs have improved, it is still a brave decision by Sony to include an EVF in a traditional DSLR-type camera.
The 10fps shooting rate found in the Alpha 55 is the fastest in its class, and by quite a margin – the camera’s closest rivals come in at just 7fps. Although for most users this will be ample, those extra three frames per second can really make the difference to sports and wildlife photographers. The Alpha 55’s 10fps shooting rate is available in raw and JPEG mode.
Another attention-grabbing feature of Sony’s new model is a new 15-point phase-detection AF system with three extra-sensitive cross-type sensors (also on the Alpha 33). A 1,200-zone evaluative metering mode (again found in the Alpha 33) links to the AF system and interprets the scene.
Sony was one of the last manufacturers to introduce HD video to its DSLR range, with the Alpha 55 being among the first batch launched in August. While contrast-detection AF is common for video, the phase-detection AF found in the Alpha 33 and 55 should ensure faster and more fluid focusing.
One advantage the Alpha 55 has over the Alpha 33 is a new 16.2-million-effective-pixel, APS-C CMOS sensor, which is Sony’s highest-ever resolution in an APS-C camera. The company’s sensor-based image stabilisation offers up to 4EV extra in safe handholdable shutter speeds and, combined with a maximum sensitivity of ISO 12,800 will potentially capture sharp images in extremely low light.
The fast frame rate is at the core of many handy shooting modes. Multi-frame noise reduction (NR), high dynamic range (HDR) mode and sweep panorama mode are all multiple-exposure modes; the fast frame rate means that handheld shooting is possible when using these modes, although the camera still needs to be held steady in each case. Multi-frame NR takes multiple frames and combines them for low-noise results, and in this mode ISO can be extended to 25,600. HDR mode can be found by pressing the dedicated D-Range button on the top of the camera body.
This enables a sequence of three bracketed images to be shot exposing for highlights and shadows, and producing a wider dynamic range in the final image. The sweep panorama mode is operated by panning the camera in one direction while the camera takes a series of exposures, which it then processes and combines into one panoramic image. Sweep panorama is also available in a 3D version, with an HDMI port enabling direct connection, alongside regular photos and videos, for viewing on 3D-equipped TVs.
Unlike the Alpha 33, the Alpha 55 features built-in GPS which, when activated, automatically tags photographs with data about the location. Using the supplied Image Data Lightbox software, these locations can be linked with Google maps (for more on GPS, see Features in use below). Image Data Lightbox processes image files, including raw, and adjustments can be made to key elements such as white balance, exposure and sharpness.
The Alpha 55 uses the same battery as Sony’s NEX-3, NEX-5 and Alpha 33 cameras, and gives more shots per charge than the Alpha 33 depending on whether the LCD or EVF is used during shooting and viewing.
Sony has always placed great importance on handy, fun and user-friendly features, and this is certainly the case with the Alpha 55. There are plenty of features to engage the photographer, vastly broadening his or her photographic possibilities.