GH5 Slow Motion - best frame rates?

Harry Pallenberg

Harry Pallenberg

Well-known member
Anyone done pixel peeping rez / aliasing tests of the various frame rates? links? The general consensus on the GH4 was 96fps was soft and one should step it down to 72fps for better slow motion. I'm finding at times 90, 120, 135 are WORSE than 180... other times they are cleaner. 150 seems worst all the time?
 
I can tell you 60p is fantastic. Pretty much all I need 99% of the time from a sub $2K camera. I think we expect way to much at higher frame rates for these inexpensive cameras. YMMV

 
Eric - I think I'm agreeing 4K 60p slowed down 50% or even 80% is looking way crazy sharper than the HD VFR stuff... even if I blow it up 150%. makes me think something is wrong with my VFR settings as ALL that stuff looks so 'zizzy'. PLUS having realtime or slowed down sound is quite the bonus.

Uwe - thanks for the link. Agree and 150 looks bad there as well - which is what I've been seeing in my tests.
 
All I can say is that I am having a lot of fun recording with 180fps with a wide angle lens!
Sure the quality is not that great but content is number one!
 
filmguy123 said:
does 10-bit 4:2:2 vlog hold up well in 60p?
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Yes, because you have to use an external recorder like the Atmos Shogun Inferno, Odyssey 7Q+, etc. for 10 bit, 4:2:2 UHD 60p capture. That way you can choose to use a much more robust I-frame editable codec from Apple or Avid... much easier to grade, better looking, and less computer intensive.
 
No you do not, you can shoot it internal (in non VFR mode) on the latest firmware. I'm wondering how. Log holds up there internally
 
Some test shots I have made yesterday. I wanted to see how much of a difference will show up between 60p and 120p slomos in a 24 timeline. So, build your own opinion...

4K/60P downscaled to 1080p
Lens: Leica 12-60/2.8-4.0

https://vimeo.com/219379311
 
Erik Naso said:
I can tell you 60p is fantastic. Pretty much all I need 99% of the time from a sub $2K camera. I think we expect way to much at higher frame rates for these inexpensive cameras. YMMV

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lol. Good stuff Eric. I See You Recorded Yourself For That Spot! Funny thing is when I saw you with the Canon EOS that's the cam I want!! On a serious note, did you slow down more than 50% with the shot of the guy hovering over the monitors? The frames didn't look tooo smooth. Perhaps the shutter was like 1/60?
 
Uwe Lansing said:
Some test shots I have made yesterday. I wanted to see how much of a difference will show up between 60p and 120p slomos in a 24 timeline. So, build your own opinion...

4K/60P downscaled to 1080p
Lens: Leica 12-60/2.8-4.0

https://vimeo.com/219379311
Click to expand...

Good stuff.

People should realize the different uses for 60fps vs 120fps. For instance, you can tell the detail is lost at 180fps, HOWEVER, in your mid to last scenes where the people are jogging in low contrast light the rate is very very pleasant, and one isn't noticing much on the leaves details etc... of course the lenses make a difference as well.

The Rule For Serious High Frame Rates would be to use Fast Lenses since the nature of bokeh somewhat voids out any comparisons for detail. Also, in proper lighting scenarios, other tests are needed.
 
Keep in mind Optical flow in post is also a good option. The higher frame rate one can start with the better optical flow will work. For example shooting 24p and trying to do slow motion is rather difficult for optical flow to create new in between frames due to the large gap between frames. Starting with 4k 60p and doing a 2x (200%) slow motion with optical flow (120fps) in post is very easy and will likely not result any any weird artifacts. the 60p is already 2.5x more frames than 24p so each frame has much less space in between and optical flow will not get as confused trying to figure out what the motion vectors are trying to do. If you absolutely must have 180fps then optical flow would only be a 3x (300%) slow motion on the 4k 60p. You gain the same level of detail and quality as any other 4k from the GH5 with perhaps an occasional chance of an artifact. The chances should be very slim however and unless you are shooting a water fountain or a bullet through an apple I doubt it will artifact too much. It is worth a try if you absolutely need to keep your project at 4k and should look visually better 98% of the time.

I have used optical flow on HD 60p in a 24p project that was virtually perfect even with a lot of random movement.
 
Thomas Smet said:
Keep in mind Optical flow in post is also a good option. The higher frame rate one can start with the better optical flow will work. For example shooting 24p and trying to do slow motion is rather difficult for optical flow to create new in between frames due to the large gap between frames. Starting with 4k 60p and doing a 2x (200%) slow motion with optical flow (120fps) in post is very easy and will likely not result any any weird artifacts. the 60p is already 2.5x more frames than 24p so each frame has much less space in between and optical flow will not get as confused trying to figure out what the motion vectors are trying to do. If you absolutely must have 180fps then optical flow would only be a 3x (300%) slow motion on the 4k 60p. You gain the same level of detail and quality as any other 4k from the GH5 with perhaps an occasional chance of an artifact. The chances should be very slim however and unless you are shooting a water fountain or a bullet through an apple I doubt it will artifact too much. It is worth a try if you absolutely need to keep your project at 4k and should look visually better 98% of the time.

I have used optical flow on HD 60p in a 24p project that was virtually perfect even with a lot of random movement.
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I find optical flow hit or miss depending on the subject matter. Anything with limbs that move quickly, for instance, tends to look bad. Animals, sports, etc.

When it works, it's great. But I find it too hard to guess when it won't...and when it's bad, it's real ugly. I suppose if possible, it's worth it to do a few takes. One @ 4K 60p, and another @ 180p for backup.
 
filmguy123 said:
No you do not, you can shoot it internal (in non VFR mode) on the latest firmware. I'm wondering how. Log holds up there internally
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You asked about 10 bit, 4:2:2 60p specifically and I explained things correctly. For that you need a capable external recorder. 10 bit, 4:2:2 60p internal is only available at 1080p. If you're doing internal at all with the current bitrate and long GOP codec settings, then no it doesn't hold up as well as going to an external recorder.
 
DBP said:
I find optical flow hit or miss depending on the subject matter. Anything with limbs that move quickly, for instance, tends to look bad. Animals, sports, etc.

When it works, it's great. But I find it too hard to guess when it won't...and when it's bad, it's real ugly. I suppose if possible, it's worth it to do a few takes. One @ 4K 60p, and another @ 180p for backup.
Click to expand...

Yes it is hit or miss with lower frame rates but the accuracy goes up the more frames you start with. I had a friend who did a bee keeping video where he got an extreme closeup shot of bees dancing around and he slowed it down with optical flow. He shot it HD 60p and the 2.5x extra frames greatly helped the optical flow have enough information in the motion vectors to keep up with the motion. 24p is a beast with optical flow because you can have a drastic jump in motion between two frames plus you have a lot of motion blur which confuses it even more. Its hard to predict motion and build an in between frame when an arm is a blurry smudge. The more in between frames you can start with and the less motion blur each frame has the more accurate optical flow will be.
 
Can anyone speak to how internal FHD 10 bit, 4:2:2 60p holds up with vlog? VS 24p/30p?

Curious about using it for internal vlog slow motion when conformed to a 24p base, but not if the internal codec falls apart with that many FPS...

(wondering if this is part of why Panasonic won't allow VFR in the FHD 10-bit 4:2:2 mode even though 60p is available as a timebase?)
 
Cary Knoop said:
Optical flow is hit or miss. I prefer a faster frame rate.
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Yeah so do I if I can get it. I also prefer a clean down conversion. I have no problem with 2k or HD and currently do a lot of external HD to an Atomos Blade from the GH4. What I don't like is a lower quality down conversion with added aliasing. My point is somebody should try it as an option if they are concerned about the resolution loss. Either way it is a compromise. Even 4k 60p is a compromise on the GH5 since it can only do 8bit. I have done a lot of optical flow slow motion with FCPX and 60p has almost always been perfect. I would say 95% hit and 5% miss. 24p/30p is another story and is typically 50/50.
 
filmguy123 said:
Can anyone speak to how internal FHD 10 bit, 4:2:2 60p holds up with vlog? VS 24p/30p?

Curious about using it for internal vlog slow motion when conformed to a 24p base, but not if the internal codec falls apart with that many FPS...

(wondering if this is part of why Panasonic won't allow VFR in the FHD 10-bit 4:2:2 mode even though 60p is available as a timebase?)
Click to expand...

Can anyone speak to this?
 
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