Friedman sagt:
TIP #1: If you attach an SSM lens (such as “kit” 16-50 f/2.8 SSM), then DMF mode is ALWAYS available to you, regardless of the setting of this menu variable. Just turn the lens’ focusing ring at any time. There is a benefit to enabling this feature with an SSM lens attached, though: it will enable the Peaking Level function as described above.
TIP #2: If you attach an SAM lens then DMF is NEVER available to you (due to the way the internal focusing motor is designed) and hence this option will be greyed out in the menu.
Beim Tamron 70-300 USD funktioniert DMF jedenfalls einwandfrei
Gruß,
Christian