[aidualk]

bei dpreview:

With the A99, Sony introduces Depth Map Assist AF technology to offer predictive autofocus. When enabled, Depth Map Assist AF works by collecting contextual information about a subject once the camera has achieved initial focus using one of its 19 AF points. This then helps the camera to predict subject movement between exposures. By using this additional information, the user does not need to specify so much information about the expected behavior of the subject as is necessary when configuring the AF tracking systems on pro-grade Canon and Nikon DSLRs (a process that has become easier in the latest generation, but still requires careful consideration to get the best results).

In practice, this dual AF system provides a marked improvement over previous Sonys, particularly when paired with the AF range limit feature we'll describe shortly. But we would hardly classify the A99 as a sports photographer's camera. At indoor events, like collegiate basketball games, the AF system can be a bit slow to lock onto fast moving subjects coming straight towards or away from the camera. In the 6 fps burst mode we often found more precise focus on the second or third frame. And once the camera does achieve sharp focus, the predictive autofocus of the AF assist points cannot reliably keep up with subjects running at full speed. In burst mode sequences shot under these conditions, we rarely found more than two consecutive frames in sharp focus.

No one could reasonably expect the A99's AF performance to be on par with the much more expensive pro-oriented Nikon D4 and Canon EOS-1D X cameras. And while Sony has made obvious strides over earlier Alpha-series models, a direct peer like the Canon EOS 5D Mark III offers a nearly equivalent frame rate, wider AF array coverage and a more robust predictive traking system. The A99 does have the advantage of simplicity of operation. Set the camera to AF-D mode and choose from among the AF area options. That's literally all there is to it. And for the photographer looking to occasionally capture recreational or family sports, the A99 can produce good results, if you set your expectations accordingly.

Ich versteh nur Bahnhof. Und damit meine ich nicht die englische Sprache.
Hat einer tatsächlich begriffen, was es mit AF-D auf sich hat und kann es einem Nicht-Binären wie mir einfach und verständlich erklären?

danke und Gruß

aidualk