The many ‘world firsts’ on the Sony Alpha 77 include a 24.3-million-pixel APS-C sensor and a 2.4-million-pixel XGA OLED electronic viewfinder. In fact, there’s much to be excited about
Sony’s latest AF system offers 19-points, 11 of which are the more sensitive cross-type. The arrangement is in three zones grouped in the central part of the frame. AF modes include wide (all three zones), local (all AF points selectable individually), spot (central AF point) and zonal (all points within one of the three zones).
One area that really does benefit from the translucent mirror is autofocus, because a portion of light is continually directed onto the phase-detection AF sensor. Phase-detection AF is available in still capture, including the 12fps shooting mode. More importantly for those who use video, it is available full time.
By and large, AF is very responsive for fast-moving subjects. In such conditions – the erratic movement of football players, for instance – and indeed any condition, it is necessary to keep the subject in the central area of the frame occupied by the 19 AF points.
Manual focus has two very useful functions to enhance the ease of correctly focusing on a subject: peaking, and a magnification aid that blows up the scene for closer inspection. The former displays the point of focus by a user-defined yellow, red or white. Of the low, mid and high levels, I found mid to be accurate for a variety of subjects. Both modes are particularly handy tools, especially when using lenses with a very shallow depth of field
Every one of these frames is in focus thanks to the continuous phase-detection AF system