Choosing the appropriate frame rate for your underwater video project

I am expecting some controversy anyway here it is

https://interceptor121.com/2019/11/22/choosing-the-appropriate-frame-rate-for-your-underwater-video-project/

No controversy here! I use 30p since I'm in the US, and that's as high as my AX700 goes.

I do use 1/125th exposure most of the time, as it seems to give less blur and crisper frame grabs which my dive buddy turns into some pretty nice stills. The low light performance doesn't seem to suffer.

29 minutes ago, wydeangle said:

No controversy here! I use 30p since I'm in the US, and that's as high as my AX700 goes.

I do use 1/125th exposure most of the time, as it seems to give less blur and crisper frame grabs which my dive buddy turns into some pretty nice stills. The low light performance doesn't seem to suffer.

That is correct 1/125 gives less blur but the idea of video is that you have blur to give a sense of flow in the motion. Clearly this does not work if you want to framegrab but I also take stills at 20 megapixels that I can print A3 for that purpose ;-)

No controversy or at least not a lot  

Good technical info as usual in the article. 

Next time if you want to mix and match frame rates use Resolve. Before putting the clip on the timeline right click it choose clip attributes and change its frame there to what your timeline is. You ll be amazed by the result

Useful info but I do not really change the frame rate in the same clip it was more to discuss how to choose the frame rate.

Shutter speed is a related topic but was not the focus. On the controversy subject am getting attacks from GoPro community elsewhere obviously there is confusion between smooth footage and smooth operators

If I see another slow down clip of a turtle that is already slow on facebook I will probably be sick

47 minutes ago, Interceptor121 said:

Useful info but I do not really change the frame rate in the same clip it was more to discuss how to choose the frame rate.

Shutter speed is a related topic but was not the focus. On the controversy subject am getting attacks from GoPro community elsewhere obviously there is confusion between smooth footage and smooth operators

If I see another slow down clip of a turtle that is already slow on facebook I will probably be sick

Not on the same clip but you may  have to combine clips shot in different framerates in the same timeline. Eg land shots at 24fps and uw shots at 30fps in a 24fps timeline.

I really cant see why someone has to slow down clips to smooth them with all these e-stabilization that the newer go pros offer.

I feel you when it comes to turtles

1 minute ago, Lionfi2s said:

Not on the same clip but you may  have to combine clips shot in different framerates in the same timeline. Eg land shots at 24fps and uw shots at 30fps in a 24fps timeline.

 

 

30 fps in a 24 fps timeline is lame why would you want to do that? The level of slow down is little and there is no gain in 'stabilisation' you then have the issue that you need to shoot 1/50 or 1/100 to make 24 fps look goof but 30 fps wants 1/60 or 1/125 I don't get it

Why don't let fish move at the speed they really do? I can understand a planned slow motion for something specific you want to capture like in a documentary but to alter systematic the reality is weird

2 minutes ago, Interceptor121 said:

30 fps in a 24 fps timeline is lame why would you want to do that? The level of slow down is little and there is no gain in 'stabilisation' you then have the issue that you need to shoot 1/50 or 1/100 to make 24 fps look goof but 30 fps wants 1/60 or 1/125 I don't get it

Why don't let fish move at the speed they really do? I can understand a planned slow motion for something specific you want to capture like in a documentary but to alter systematic the reality is weird

Because in the example given you may have 30fps uw footage and 24fps land footage. The 30fps clip to 24fps timeline can be made to work with the technique I told you before without any problem. The 24fps clip to 30fps timeline cant be done effectively. 

I do not see why I would have a 30 fps underwater footage and a 24 fps land footage unless the underwater camera is not capable of 30 fps? 

Maybe the opposite I may have a 30 fps land footage because I have main powered lights at that point I would also have 30 fps underwater footage consistently which is what I would do if I was living in an NTSC country to avoid any possible issues

I live in a PAL country and I shoot 24p even when I am on land period. The reason for the 24p choice is because my camera has better flexibility for it otherwise I would probably shoot 25p there are no benefits of any sort between 24/25/30 and actually lower frame rate on I only codec means higher IQ

9 minutes ago, Interceptor121 said:

I do not see why I would have a 30 fps underwater footage and a 24 fps land footage unless the underwater camera is not capable of 30 fps? 

Maybe the opposite I may have a 30 fps land footage because I have main powered lights at that point I would also have 30 fps underwater footage consistently which is what I would do if I was living in an NTSC country to avoid any possible issues

I live in a PAL country and I shoot 24p even when I am on land period. The reason for the 24p choice is because my camera has better flexibility for it otherwise I would probably shoot 25p there are no benefits of any sort between 24/25/30 and actually lower frame rate on I only codec means higher IQ

Because you might get footage from different cameras, different locations, different operators etc. Because if it is a bit choppy underwater and you dont want to be on the bottom because its sensitive or because you have to move, that little bit of slow down you get from 30fps to 24fps will help. Because that extra second you might get will make your footage to sync with the music beat.

And if done correctly you wont be able to notice the dropped frames (the cause of the problem) if you just go and slow it down then yes you will have bad results. How many they will notice is a different conversation.

Because you might get footage from different cameras, different locations, different operators etc. Because if it is a bit choppy underwater and you dont want to be on the bottom because its sensitive or because you have to move, that little bit of slow down you get from 30fps to 24fps will help. Because that extra second you might get will make your footage to sync with the music beat.
And if done correctly you wont be able to notice the dropped frames (the cause of the problem) if you just go and slow it down then yes you will have bad results. How many they will notice is a different conversation.

2 minutes ago, Interceptor121 said:

 

30 to 24 fps is 20 % reduction it won’t look any smoother
I think is about planning not doing a mix up of material that you have not normalised hence you choose your frame rate at the start of the project
Anyway the purpose of my post is about planning your clip not doing remediation work lol


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20% is almost 1/4 its not huge but its something. Try it 

Good discussion!

20% is almost 1/4 its not huge but its something. Try it [emoji6]

 

Good discussion!

I see zero benefits. I shoot 400 mbps 24p this gives me a 2.08 MB frame

400 mbps at 30p gives me 1.67 MB size frame

I then dilute my 30 fps to 24 fps loosing 20% quality

Final outcome 0.8x0.8=0.64 or 36% image quality loss for a 20% fake stabilisation improvement

This makes no sense to me unless I was shooting prores and I was sure the frame size was more or less constant

Edit I think I did some double counting is 20% IQ loss for 20% ‘smoother footage’

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34 minutes ago, Interceptor121 said:

 

I see zero benefits. I shoot 400 mbps 24p this gives me a 2.08 MB frame

400 mbps at 30p gives me 1.67 MB size frame

I then dilute my 30 fps to 24 fps loosing 20% quality

Final outcome 0.8x0.8=0.64 or 36% image quality loss for a 20% fake stabilisation improvement

This makes no sense to me unless I was shooting prores and I was sure the frame size was more or less constant

 

Edit I think I did some double counting is 20% IQ loss for 20% ‘smoother footage’

 

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Not everything is in the numbers

Many times the theoretical optimum is not the practical optimum. 

For me the idea is know your "enemy" and adjust accordingly. 

I see only problems and no benefits as 24 and 30 require different shutter speed which was the whole reason 30 fps was invented
Then if you shoot at 1/50 your footage looks juddery if you shoot 1/100 same
You need 1/125 the 24p looks strobic

As you say know your enemy so you can avoid it lol


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You think that if you take 24fps up to 1/60 sec or 30 fps down to 1/50 sec (both underwater) anyone will spot the difference if you know what you are doing in conforming them? Yeah if you run it through ffprob and if you analyse frame by frame yes but who does that outside the purpose of writting a blog post or similar?

Its a good think rules are made to be broken

53 minutes ago, Lionfi2s said:

You think that if you take 24fps up to 1/60 sec or 30 fps down to 1/50 sec (both underwater) anyone will spot the difference if you know what you are doing in conforming them? Yeah if you run it through ffprob and if you analyse frame by frame yes but who does that outside the purpose of writting a blog post or similar?

Its a good think rules are made to be broken

 

I am more saying that technique serves no purpose and is a waste of time bitrate and efforts exactly for the reason you say

Why do things that cost time have possible side effect and zero benefits?