GH5 GH5s - 240FPS Question

B

Bassman2003

Veteran
Hello,

I have a quick question for the GH5s owners: How does the 240fps setting act with regards to 60p timelines? I read that the way to get 240fps, you need to set the camera to 24p and film through variable frame rate. Do these recorded frames work well on timelines other than 24p? Or is the recorded clip a 24p clip that is not as effective on other timelines?

I sometimes film sports in 60p and shoot slomo to go on these timelines and am wondering if I would film 240fps on the GH5s would it act well.

Also, can you set the shutter speed to whatever you want in the 240fps mode? Thanks!
 
With true cinema cameras you can choose a timeline of 24p, 30p or 60p and then overcrank a higher frame rate over them (or under them if that’s the intent).

If the GH5 only allows you to choose a 24p timeline then the conformed 24p footage may or may not work well on a 60p timeline just like normal motion 24p footage. We’ve all mixed in the past and sometimes - depending on the content - the difference (any NLE frame adding or subtracting) is noticeable and sometimes not.

Panasonic is the only company I’ve ever seen actually allow you to set a shutter speed of 1/50 for 60p footage so I’m not sure about the speed for 240fps, but it’s highly unlikely you’ll be able to go lower than 1/240.

If the GH5 behaves like other cinema cameras and allows for 60p timeline overcranking then the 60p files would play perfectly in your 60p timelines.
 
I found some 240fps footage that some nice soul offered for download. The clips look and play fine in Edius on a 1080p60 timeline. In comparison, the slow motion was the same on a 24p timeline. This is one of the strong points of Edius. You can throw any type of footage a the timeline and it automatically adjusts to the timeline frame rate in real time.
 
All modern NLEs just add frames. They started doing this about 10 years ago when the world was slowly transitioning to 60 progressive frames.

If you move through the footage with your arrow keys you’ll see duplicate frames the NLE has created.

A 24p timeline will only have one of each for the second; 24 frames per second (if the conformed speed is 24p).

Normal viewers will not notice the difference, but experienced editors with high-speed probably would.
 
And if you used a RED or Blackmagic and overcranked 240fps over 60p and took that 60p file and dropped it into a 24p timeline, the NLE would subtract frames from the file so it can playback at 24p.

[Delayed extension of the thought above; meant to send that right after the ^.]
 
Yes, I mainly wanted to see if the clip duration changed between the two different timelines. As long as the NLE has access to all of the 240 frames, it does not matter what container you put it over as long as the clip duration remains constant, which it did.

I do not use Premiere much but I seem to remember having to tell it to conform files of a different frame rate. I do not use any others to know how they react to different frame rates.
 
Bassman2003 said:
I found some 240fps footage that some nice soul offered for download. The clips look and play fine in Edius on a 1080p60 timeline. In comparison, the slow motion was the same on a 24p timeline. This is one of the strong points of Edius. You can throw any type of footage a the timeline and it automatically adjusts to the timeline frame rate in real time.
Click to expand...

Resolve and Vegas will do exactly the same and in the case of Vegas can do something EDIUS cannot do which is start a project at one frame rate and then change to another. So for instance in this case start a 60P HD project confirm it is slow motion from 240fps and then change project frame rate to 24P or even 29.97 interlaced. I can confirm this works. Drop frames when needed as NorBro says. They can all slow down even further with optical flow creating more frames. The GH5S can only of course do 240fps with 60P base in 1920x1080 without audio. If you want to shoot in 3840x2160 you are limited to 29.97 or 23.98 and then only to 60fps so only 50% slow.
 
Last edited:
Optical flow is something I avoid but something I really like, is to set a project frame rate of your choice, shoot at a 2:1 multiple. For example, project 30 fps, shoot at 60 fps 360 degree shutter. You keep your audio, it plays at half speed for a nice slow motion, or drop frames to speed up for real-time. Same thing for other frames rates, 24/48 fps, 25/50 fps. Be careful around LED practicals, for strobing. You can fix it in Resolve pretty well.
 
Also I recommend at least 8K for this, especially for the important research I'm doing into high end unboxing videos. To be able to capture every fiber of cardboard that comes off with the packing tape is what's needed for attracting sponsorship and clicks.

Now being serious for a minute, I think 8K for a M43 sensor makes little sense. I bet Panasonic agrees. I was watching the full test video from CVP on the Ursa 12K. Okay it wasn't an unboxing video, so not really high end work but, they remarked that with the 12K sensor you need the best resolving lenses; they threw up a number 228 line pairs per millimeter. I went searching around for numbers on some of the top 50mm (35 mm equivalent) prime lenses, eventually settling that they are all about the same near the center, or about 83 lp/mm. How did CVP come up with that number of 228 lp/mm? Pretty simple, you take the sensor height pixel count divided by 2 since a line pair is one black and one white line, and divide it by the sensor height dimension, and wha-lah... 6480/2*14.25mm= 227. The question begs, how in the world can any lens resolve what a 12k S35 sensor can do, or even 6K? The answer is you rerate the lens to a lower MTF %. MTF50 resolution is the frequency where the contrast between line pairs drops to 50%. If you let that number drop even more, say MTF10 for satellite imagery, the resolved frequency goes up but at the expense of lowered contrast. If you stick with MTF50, probably no lens resolves the S35 6K. At some given higher frequency level, fine detail might be discernable between line pairs but at a lower contrast. So then, 8K M43 isn't going to be impactful if it's even visible critically. The only practical benefit I would envision would be if they did something like the URSA by removing the color filter from some of the pixels to make unfiltered white for improving (or just keeping) the DR with the tiny pixels, and having an equal number of RGB pixels, i.e. what they are doing on URSA 12K.

I think Panasonic by jumping into the FF fray along with Olympus selling off its assets to third party together have torpedoed whatever enthusiasm M43 owners (like me) would have ever had left, since it seemed to by dying anyway. Taking so long to unveil a new 4/3 camera cannot have helped allay the doubts.

There's the doorbell, driver leaving another package to unbox. Have to run.
 
:) I would agree about the 8k M4/3rds camera but they will probably try anyway. I myself an still in search of a camera setup and am kind of down to a Canon R6 and a GH5s or GH6. This is due to lenses I already own, liking the GH series workflow, wanting a 240fps camera, needing pro stills capability and IBIS for at least one for gimbal work. So I am rooting for Panasonic but they are leaving me at the altar.
 
You must log in or register to reply here.
Back
Top