Autofocus
Image: The selective colour mode is very effective if used in more subtle methods, such as the iris of the model’s eye
The focusing is one distinction that remains between the D5100 and the more advanced D7000, which features Nikon’s superior new Multi-CAM 4800DX with 39 AF points and nine cross-type points. The Multi-CAM 1000 autofocus system used in the D5100 has featured in a range of models from the D200 to the D3100 but, considering it is now more than five years old, it still holds its own. This 11-point system is still more extensive than those featuring on some of the competition, although only the central point is of a cross-type design for added sensitivity.
Like the version on the D5000, the AF system also includes 3D-tracking. This allows the AF selection point to follow the subject across all the available 11 points as it moves around the frame, which makes shooting moving subjects easier. Although the D5100’s system may not be as complex or quite as fast as that of the D7000, it is still accomplished and locks onto subjects with ease using the powerful dedicated AF lamp for illumination of close-range, low-contrast subjects.
The contrast-detection focusing in live view mode has been upgraded from that of the D5000, but in practice this is noticeably slower than phase-detection focusing when using the regular viewfinder and still not up to the focus speeds achieved by Panasonic’s latest compact system cameras, the Lumix DMC-GH2 and G2. The full-time servo mode is useful for video, although with the kit lens attached the noise from the lens motor is very distracting; it makes the recorded sound unusable in regular volume levels unless an external microphone is plugged into the mic port and placed some distance from the camera.
