GH4 GH4 can't autofocus in 96fps mode?

Griffinity

Griffinity

Active member
My GH4 is set to AFC autofocus. (I've turned off continuous AF, because I don't like that. I like to focus with the shutter before each shot.) But when I turn on variable frame rate (VFR) and shoot in 96fps, the autofocus is disabled, so I can only focus manually. When I turn off VFR, it reverts to normal autofocus operation.

Anyone else experiencing this?

My camera is also set to cinema mode (24.00p), and I was shooting in 1080 MOV (100mbps).
 
SuperSet said:
I thought that this was intended functionality and in the manual, too. No AFC in 96fps.
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You're correct! Page 215 in the digital PDF manual, which explains Variable Frame Rate, says, "*Auto Focus does not work. *Audio is not recorded." Thanks for pointing that out! (Presumably it wouldn't work for any variable frame rate—2fps all the way up to 96.)

I wonder why that is. I'd understand the need to strip away additional processes (auto focus, audio) while processing high framerates, but strange that I can't focus before rolling.
 
This is a side effect of speeding up the sensor. The internal processor can only handle so much. 1080p 96fps in a great codec/container is a great feat. How many of us were looking at terrible JVC cameras to achieve slow motion footage in the past? Just make a setting, save it to one of your custom settings and use it only when you need it. No audio, records 96fps to a 24p timeline... beautiful! I love this camera.

I am keeping my three GH3s though. Great b-cameras.
 
How do even enable 96fps. I'm guessing threw the variable frame tab but mine is grayed out
 
A workaround for this issue is to shoot 1080/60p where autofocus works fine and conform it to 24p in post. Cinema Tools does this but unfortunately won't work with h.264. You need to convert it to PRORES first, then open Cinema Tools, hit conform and select 24p. It doesn't re-render, just changes the metadata so it plays at 24p in your NLE. Of course, you are limited to just 60p and not the other frame rates in VFR, but sharpness takes a hit in any speed over 60 in VFR mode anyway.
 
Batutta said:
A workaround for this issue is to shoot 1080/60p where autofocus works fine and conform it to 24p in post. Cinema Tools does this but unfortunately won't work with h.264. You need to convert it to PRORES first, then open Cinema Tools, hit conform and select 24p. It doesn't re-render, just changes the metadata so it plays at 24p in your NLE. Of course, you are limited to just 60p and not the other frame rates in VFR, but sharpness takes a hit in any speed over 60 in VFR mode anyway.
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Yep, if you don't need the full 96fps, 1080p 60 is fantastic, and image is a bit sharper than the 1080p 96 footage. (I don't have a problem with the 96fps 1080p footage sharpness like some do, but it is a bit softer).
 
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