Panasonic 20mm/1.7 autofocus noise?

Qaf is a form of Caf. It only refocuses when camera shake is minimal according to the manual. Turn that setting to "Off" if you want the camera to operate in AFS mode before you hit the shutter button or the video record button.

What is interesting is that the 20mm will do Caf for prefocus but not for regular focusing for pictures. It will also do Caf during video. Basically, you can do continuous auto focus for everything but burst pictures with the 20mm. It will have an audible sound though.

dr sumi said:

s_grins said:

Custom menu (snip below)

Pre AF • Off
• Quick AF

• Continuous AF Quick AF will start to try to achieve focus when it detects the camera is being held steadily.
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MFT in progress

Click to expand...

The only options I have in my menu are:
OFF
Q AF

C AF is grayed out ?

Click to expand...

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GH2, GF1, & ZS3 Sample movies
http://www.youtube.com/user/mpgxsvcd#play/uploads
http://vimeo.com/user442745
GF1 Pictures
http://www.dpreview.com/galleries/4222674355/albums

One thing more:
Set this dial to SAF





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MFT in progress

That dial has no affect with the 20mm with respect to AFS vs. AFC. If it is set to AFC it will ask you to switch to AFS but it will operate as AFS only.

s_grins said:

One thing more:
Set this dial to SAF





--
MFT in progress

Click to expand...

--
GH2, GF1, & ZS3 Sample movies
http://www.youtube.com/user/mpgxsvcd#play/uploads
http://vimeo.com/user442745
GF1 Pictures
http://www.dpreview.com/galleries/4222674355/albums

OP has CAF grayed in menu

It is my guess, that when top dial set to AFC, menu CAF option is grayed. I do not know for sure and do not camera with me to check it out.

Anyway, it will not hurt stills shots, and with my G1 I'm just a baby about video settings and their relations with what is set for stills
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MFT in progress

A lot of people don't realize that there are 3 separate Auto Focus settings on the GH2.

1. The AFC,AFS,MF dial on the top of the camera controls what method of focus is used when you take a still picture only. It only operates when you actually take the picture.

2. The pre-focus option in the tools menu allows the camera to use AFC(QAF or CAF) or AFS before you take a picture or start recording video. It has no affect at all once you start taking a video or are in the process of taking rapid still images.

3. The movie menu option to do "Continuous Auto Focus" only controls whether the camera uses AFS or AFC during video. If you select MF on the control dial it will override this option during movies. Set it to off to do AFS during videos.

s_grins said:

OP has CAF grayed in menu

It is my guess, that when top dial set to AFC, menu CAF option is grayed. I do not know for sure and do not camera with me to check it out.

Anyway, it will not hurt stills shots, and with my G1 I'm just a baby about video settings and their relations with what is set for stills
--
MFT in progress

Click to expand...

--
GH2, GF1, & ZS3 Sample movies
http://www.youtube.com/user/mpgxsvcd#play/uploads
http://vimeo.com/user442745
GF1 Pictures
http://www.dpreview.com/galleries/4222674355/albums

smoking?

20 1.7 is not a good lens for manual focusing when shooting video.

Try to manual focus on two subjects (one at a time) and you will see the focus ring never returns at the same mark after focusing back to the first subject.
For me it's a deal breaker .
It's a good lens for taking picture though.

I think that goes for all native M43 lenses: because of the focus-by-wire in combination with gearing depending on rotation speed, the ring position is not linked to the focus distance directly. I doubt that's different for lenses other than the 20mm...

Bizzarrini said:

I think that goes for all native M43 lenses: because of the focus-by-wire in combination with gearing depending on rotation speed, the ring position is not linked to the focus distance directly. I doubt that's different for lenses other than the 20mm...

Click to expand...

In all the lens reviews for m43-lenses here on dpreview they have mentioned that the MF is focus-by-wire, so I guess it goes for all of them like you say. I don't like it, but then again if I want to use MF there are so many other lenses to use...

I find that the 20/1.7 hunts for focus quite a bit in video/AF mode. Or maybe it's just more obvious because it focuses much slower than the 14-140?

abolit said:

20 1.7 is not a good lens for manual focusing when shooting video.

Try to manual focus on two subjects (one at a time) and you will see the focus ring never returns at the same mark after focusing back to the first subject.
For me it's a deal breaker .
It's a good lens for taking picture though.

Click to expand...

I agree, and it's not just unpredictable -- it's also quite slow as it takes many rotations to go from close focus to infinity.

Has anyone compared with the X-lens 14-42? How does it compare regarding AF noise and AF-speed and AF-accuracy?