lets talk autofocus

A

ampsonic

Active member
Hello all,

Loving my GH1, loving the new 20mm 1.7 lens. What I'm not loving is the confusing settings for autofocus. (Well, they're probably not confusing, I'm just having trouble.)

Can someone take me step by step on how to set up the autofocus so that it will function more like autofocus on every other video camera I've used? From what I can tell thus far, I always have to push the shutter 1/2 way down to get it to focus (and 1/2 the time, I accidentally stop recording...)

My last gig I got frustrated and shot manual focus the whole night.

Can someone help? AF-C / AF-S, then the different modes in the menu...?
 
ampsonic said:
Hello all,

Loving my GH1, loving the new 20mm 1.7 lens. What I'm not loving is the confusing settings for autofocus. (Well, they're probably not confusing, I'm just having trouble.)

Can someone take me step by step on how to set up the autofocus so that it will function more like autofocus on every other video camera I've used? From what I can tell thus far, I always have to push the shutter 1/2 way down to get it to focus (and 1/2 the time, I accidentally stop recording...)

My last gig I got frustrated and shot manual focus the whole night.

Can someone help? AF-C / AF-S, then the different modes in the menu...?
Click to expand...

I noted and posted on this, and it seems others have seen it too...

It's a 'feature'...

As far as I can tell, at the moment the only way to get a autofocus-single(*), is to enable autofocus, depress shutter release 1/2, get focus, then manually turn the AF knob to 'manual', thus locking the focus. Then as things change, manually turn the AF knob to AFS, depress shutter release, hoping against hope to no 'stop' the video, and reacquire focus, then turn knob to manual...

I've not tried the latest official firmware update available since May 10, 2010, to see if there is any difference in this regard. (I suspect not...).

*The alternative is to get a focus mechanism, and a real focus puller, if you want to more accurately track moving objects in the scene, that 1) are not in the 'focus' area, 2) are moving more quickly than the autofocus convergence processing.
 
Unfortunately a follow focus likely won't work on the 20mm f/1.7 (at least on on the GH1...flash housing gets in the way.)

I've found the manual focus on the 20mm to be great...perfect amount of dampening for most video work...but yeah that's the only option for autofocus. Have a light touch on that shutter button. The 14-140mm will do AFC.

For getting smooth video autofocus with both lenses I have had the best luck with setting a track point...seems to reduce seeking.
 
For getting smooth video autofocus with both lenses I have had the best luck with setting a track point...seems to reduce seeking.
Click to expand...

Can you explain that a bit more?

I think what I actually want is AF continuous, I just can't seem to get it to do a good job.
 
There's different kinds of focus you can select (center, face tracking, etc) one of them is where you set a track point and it tries to follow it around and keep focus on it.
 
One complaint I have is the AF/AE lock button on the GH1 body. I can only set it once while recording. Then if I turn it off to allow a re-focus, I can't turn it back on.

Turning the Focus mode knob mid-recording isn't that bad, its just not ergonomic for a person trying to hold steady.

I find the 20mm F/1.7 is quickest for auto-focus when set to AF-S, and the AF mode is set to a small area in the center. You can adjust the size of the detection box by pressing down or up and then adjusting the dial.
 
I find the 20mm F/1.7 is quickest for auto-focus when set to AF-S, and the AF mode is set to a small area in the center. You can adjust the size of the detection box by pressing down or up and then adjusting the dial.
Click to expand...

And then you 1/2 press the shutter when you want it to focus?
 
Ben_B said:
There's different kinds of focus you can select (center, face tracking, etc) one of them is where you set a track point and it tries to follow it around and keep focus on it.
Click to expand...

So this works in video mode?

thanks in advance
 
Ben_B said:
There's different kinds of focus you can select (center, face tracking, etc) one of them is where you set a track point and it tries to follow it around and keep focus on it.
Click to expand...

The track point doesn't work in video, unless I am missing something....
 
mojo43 said:
The track point doesn't work in video, unless I am missing something....
Click to expand...

It works on the G10/G2 but not on the GF1,GH1, and GH2. This video shows it in action. It will revert to area refocus if you hit record while in focus tracking mode on the GF1,GH1, or GH2.

Thanks goes to the author of the video for pointing this feature of the G10/G2 out. I didn't realize those cameras could do this until he posted his videos. A hacked G2 is looking like a really good option if you are on a tight budget right now.

 
Ben_B said:
For getting smooth video autofocus with both lenses I have had the best luck with setting a track point...seems to reduce seeking.
Click to expand...

Ben seems to state that it does work, but I can't figure out how it is possible...
 
rambooc1 said:
I think it works in all other modes except creative movie mode. Try it with the top mode button set to M not creative. (GH1)
Click to expand...

I can't seem to get it to work... I tried it in M mode and when the video starts the tracking goes away.
 
You must log in or register to reply here.
Back
Top