Lumix G9: Any solution to video CAF problems?

[Kawika Nui]

Recently got a G9 and have been playing with it to get used to it and see how it performs.

I was surprised and disappointed to find major deficiencies with the video CAF (shooting mp4, 1080/60p). In a very simple shooting environment, the camera kept defocusing and refocusing for no reason. There is almost no movement toward or away from the camera, and the distance is close to infinity anyway. The video starts in focus, then arbitrarily moves out of focus and back a couple of times - all in a very short time.

Does anyone have a suggestion for fixing this?

 

[jrsforums]

Because if they get a long ride, they are coming toward the camera in a hurry. If they get a very long ride, they will practically fill the screen at the end of the ride.

And because CAF is supposed to work. If it works properly, why not leave it on and be ready for any moving subject? I might spot an osprey or a flight of pelicans coming toward me.

Just throwing this out but no idea how reliable it is... Have you tried the AF Tracking mode?

I just tested having it lock onto my lens cap and it seemed pretty "sticky", though I guess tracking a surfer is going to be a whole different scenario than waving a lens cap around in front of the camera.

Tracking mode, according to most reviewers, does not work very well.

Anyhow, I solved the problem.

1. Turn off CAF in Video; set AF dial to AFS.

2. Turn on Eyepiece AF.

Problem solved as long as you shoot using the EVF for video, which is what I always do. (In fact that is one of the main reasons I went to mirrorless - can't stand shooting video outdoors in bright sun, using the screen.)

Thanks for your inputs!

I am a bit confused by your “success”. Eye AF=on with AFS will acquire focus with each “activation”,

Right. And this stops the needless, random de-focusing and refocusing that the camera likes to do while shooting a moving subject that is maintaining a fairly constant distance (more or less infinity) from the camera (i.e., moving more or less across the field of view), as described in my original post.

much like pressing the half-shutter or back-button (with AF=on set). AFS will not continually refocus, but will hold current focus until reactivated. This is why I use back button as I can continually reactivate (reacquire focus) as the scene changes.

Maybe I a missing some other setting you have which makes this successful for you.

What stops it is turning CAF off. Eye AF has nothing to do with it. You do, however, lose control of when AF takes place, for example, if you take eye away and then look back.

If you only want to focus once, leave it on shutter half press. AF during video is only AFS, not AFF or AFC.

If you want control, put it on back button

Yes. ++1

 

[MikeDV]

Sorry for the late reply. I just upgraded to the G9 as well from a G85 and am just starting to get time to play with some of the settings.

Have you downloaded the guide that Panasonic published with suggestions for focus settings in different situations?

It goes into great detail on all of the focus modes and settings and gives suggestions based on different shooting scenarios.

LUMIX AF Guidebook

 

[MikeDV]

The LUMIX AF Guidebook calls out surfing as an example of when you would use the following settings:

The main subjects continue to be tracked even when obstacles appear or the subjects move out of the AF area. This setting is recommended, for example, when shooting sports action where the subjects move quickly, the subjects move out of the AF area during handheld shooting, other players cross in front of the subjects, or obstacles enter the frame.

AF Sensitivity [ -1 ]
With this setting, the focus strongly persists. In situations such as doing the butterfly stroke when swimming, where the subject's face is often hidden from view, the focus remains in the initial position, preventing it from moving to the background, to continue shooting the main subjects.

AF Area Switching Sensitivity [ +1 ]
This is effective for movements that greatly change the position within the frame.

Moving Object Prediction [ +2 ]
This copes with situations where the subject suddenly stops moving or changes direction. It is effective, for example, in a soccer match to keep surrounding players inside the frame while clearly capturing the player who has the ball.

 

[Archiver]

I didn't know there was an option for anything else except CAF when shooting video. I always shoot with the lever set to AFS but in video mode the camera always shoots CAF.

You can turn off video CAF (menu, video tab, page 1/4, Continuous AF) and use the touchscreen to refocus only when necessary.

Exactly what I was looking for. Thank you! This was never an issue with any other Panasonic camera I've had, and I was a bit worried that this AF hunting issue was a fault, or something that couldn't be turned off. Great to know that it's an option.

 

[Bassaidai]

Just a "thanks" to you, Mike, for pointing out that AF Guidebook document. I haven't heard of that before - good reading!

--
Bass
If things appear to good to be true - they're usually neither of both.