Nikon Df User Manual page 341

A
AF-S/AF-I Teleconverters
The table below shows the focus points available for autofocus and
electronic rangefinding when an AF-S/AF-I teleconverter is attached.
Note that the camera may be unable to focus on dark or low-contrast
subjects if the combined aperture is slower than f/5.6. Autofocus is not
available when teleconverters are used with the AF-S VR Micro-Nikkor
105mm f/2.8G IF-ED.
Maximum
Accessory
aperture of
lens
f/4 or
faster
TC-14E,
TC-14E II
f/5.6
f/2.8 or
faster
TC-17E II
f/4
f/5.6
1 Focus data for focus points other than the center focus point are obtained
from line sensors.
2 Single point AF is used when 3D-tracking or auto-area AF is selected for
AF-area mode (0 62).
3 Autofocus not available.
Focus points Accessory
TC-20E,
TC-20E II,
TC-20E III
1
TC-800-
1.25E ED
2
3
—
Maximum
Focus points
aperture of
lens
f/2.8 or
faster
f/4
—
f/5.6
f/5.6
1
3
2
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