GH2 Frame Rate Oddities

J

Jim Simon

Veteran
I loaded up a new patch today (Driftwood Cluster v7 'Apocalypse Now' - 6 GOP Nebula '444 Soft' Matrix) and I was testing it out. I noticed that the 720p/60 modes (H and SH) don't actually record 60 unique frames as expected. Rather I got 30 frames in a 60p file, each of the 30 recorded frames was simply duplicated to get 60. Is this normal for the GH2, no genuine 60p recording? Or is this related to the patch?

Before I loaded the patch, I also changed the frame rate for the MJPEG HD mode from the "who the hell wants" 30 fps to the "now this is something we can use" film standard of 24 fps. I notice the cadence was off. Seems the sensor was still reading off 30 fps and just doing some frame skipping to squeeze it into the desired 24 fps. Is this also expected? Nothing I can do to get actual 24fps from the sensor in MJPEG mode?
 
Wow! 120 people have read the question, and not a one of you has ever shot 720p/60 footage?

I guess it's not that surprising. I mean, once you can shoot the film standard of 24, why would you ever want your stuff to look like video?
 
How are they duplicated frames? How did you check? Have you tried any type of slow mo to see what is there? I know that in FCP when you scroll through the clip one frame at a time, it will appear as if they are just duplicated frames. But when you slow down to 50%, it gives you all 50fps.
 
I've shot 60p and you get 60 frames.

Is it possible you were on a shutter speed lower than 1/60th?
If you shoot lower than that you get repeated frames since obviously it's not possible to have 60p and expose each from for 1/50th a second.
 
Nathan nailed it. I was still on the standard of 1/50th for 24p. Forgot to change that when I switched to 60p.

I'm a little surprised the camera allows that. The shutter speed will go down below 1/25th for stills, but not for 24p video (appropriately). I would have expected it to bump up to 1/60th by itself when I switched to 60p so it works properly.
 
Glad to help.

On my GH2 you can go below 1/25th in HBR and 24p mode, which gives you that smeary look.
It can be useful - if you want that dreamy effect or in very low light situations.

But it does mean it can catch you out.

If you're filming 60p for slowmo you'd generally want to set your shutter speed at 1/120 anyway.
 
Strange. I never shoot HBR, but in 24p I can't go below 1/25th (not that I'd want to anyway). I only noticed the camera itself can do that when I was shooting a still.

Unfortunately, just like we can't get to the proper 1/48, we also can't get to the proper 1/120. We have to 'settle' for 1/125.

I do like the 'Film Mode' of the AF100, where you can set a 180 degree shutter, and it changes the actual shutter speed to match the frame rate you're at. I wish all cameras had that capability.
 
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