松下DFD视频对焦不行，还是相位对焦好（索尼佳能）# PhotoGear - 摄影器材
b*s
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“Autofocus in video can exhibit focus hunting” 看来拍业余拍拍视频还是选择
索尼和佳能比较好，平滑性可以得到保证。
Autofocus in video is noticeably improved form the GH4, but even with
improved DFD technology the camera still doesn't have a true sense of depth
like it would with a phase detection system. As a result, the camera still
has a tendency to hunt for focus, creating a wobble as focus ratchets back
and forth.
You won't see the huge, obvious swings in focus we traditionally associate
with contrast detect AF, but a more subtle wobble or shake. In certain
situations you may not even notice it, but in others – for example, when
you have slightly out of focus point sources of light in the background –
it can be quite noticeable. The video clip above shows an example of this
phenomena: the neon sign in the background wobbles as the camera tries to
maintain focus.
We can't help but feel this may be a missed opportunity for Panasonic. Over
the past couple years we've seen very effective on-sensor phase detect
systems for video, including Canon's dual pixel autofocus, as well as the AF
system on the Sony a6300/a6500 twins. Panasonic's insistence on sticking
with DFD autofocus technology for a camera primarily aimed at video shooters
doesn't seem to be the best choice, and takes away from what is otherwise a
very good video camera.
As with any AF system, there's still enough variability when shooting video
that you'll probably want to stick with manual focus for very precise work,
such as narrative filmmaking, but a good AF system is really important for
things like documentary shooting, or even family get togethers, where motion
is less predictable. You can certainly use the GH5 in these situations, but
it some cases it may produce some subtle, though noticeable, focus hunting.
索尼和佳能比较好，平滑性可以得到保证。
Autofocus in video is noticeably improved form the GH4, but even with
improved DFD technology the camera still doesn't have a true sense of depth
like it would with a phase detection system. As a result, the camera still
has a tendency to hunt for focus, creating a wobble as focus ratchets back
and forth.
You won't see the huge, obvious swings in focus we traditionally associate
with contrast detect AF, but a more subtle wobble or shake. In certain
situations you may not even notice it, but in others – for example, when
you have slightly out of focus point sources of light in the background –
it can be quite noticeable. The video clip above shows an example of this
phenomena: the neon sign in the background wobbles as the camera tries to
maintain focus.
We can't help but feel this may be a missed opportunity for Panasonic. Over
the past couple years we've seen very effective on-sensor phase detect
systems for video, including Canon's dual pixel autofocus, as well as the AF
system on the Sony a6300/a6500 twins. Panasonic's insistence on sticking
with DFD autofocus technology for a camera primarily aimed at video shooters
doesn't seem to be the best choice, and takes away from what is otherwise a
very good video camera.
As with any AF system, there's still enough variability when shooting video
that you'll probably want to stick with manual focus for very precise work,
such as narrative filmmaking, but a good AF system is really important for
things like documentary shooting, or even family get togethers, where motion
is less predictable. You can certainly use the GH5 in these situations, but
it some cases it may produce some subtle, though noticeable, focus hunting.
