Top Highlights

• diagonal lines (figure 1-10). These sensors are the most useful because they focus on just about any type of subject. The upside is that they work really well, but the downside is that
• How AF Works Modern Nikon digital single-lens reflex (DSLR) cameras use AF modules made with charge coupled device (CCD) imaging sensors. These AF sensors are located inside the camera body toward the bottom, underneath the mirror. Light passes through the main reflex mirror and hits another mirror that directs the light down to the AF module
• Three significant factors—light level, subject contrast, and distinct lines—influence AF sensor performance, including the ability to acquire and track focus
• Many other elements need to be considered to create a sharp photograph, such as the following: Subject movement Camera shake and vibration Shutter speed Lens quality Sensor quality and resolution AF sensor calibration High ISO noise Long exposure noise
• Single-servo AF (AF-S) Continuous-servo AF (AF-C) Automatic-servo AF (AF-A) Full-time-servo AF (AF-F) is used on some cameras in video mode