24fps vs 30fps

[Rodrigo Violante]

I'm trying to shoot at the maximum quality possible for an underwater video so I have 2 options (actually 3) 24fps or 30 fps and I can maybe put 38fps at 8k WS.

I know at 24fps it gives you a more film alike experience, but my fear is the slow motion, if I decided to go 24fps I can't slow motion at all, so I'm wondering what issue will I have if I shoot at

38fps (project base 38 fps, so I can have sound) and then playback at 24fps.

What will be my biggest disadvantages, is it only the motion blur? because I will have to be at 38fps and 1/38 or 1/76 of shutter speed?

Really sorry for this amateur questions I'm sure here I'm asking the most pro audience but I don't believe I will get a better answer anywhere else.

Thanks

Rodrigo

 

[Samir Patel]

Well maximum quality probably comes with the lowest compression ratio.
The other matter is sharpest frames that would come with a higher shutter speed.
So I would suggest maybe 36fps/ws so it is exactly 1.5 times 24p and choose a higher shutter speed maybe 1/100 or something.
Add some extra lights from above to get your exposure right.
If you need some help experimenting let me know. I'm in the area.

 

[Darek Sepioło]

If you plan to shoot underwater then why bother with the sound. Shoot 38fps and set the project at 24fps you'll get cinematic look in slow motion.
I usually shoot 50fps with project set at 25pfs

 

[Nick Morrison]

If you plan to shoot underwater then why bother with the sound. Shoot 38fps and set the project at 24fps you'll get cinematic look in slow motion.
I usually shoot 50fps with project set at 25pfs

That makes sense.

Shooting 23.98 at 36fps is nice idea too, as the math is clean (36 frames being 50% slower than 24 frames)

 

[Rodrigo Violante]

If you plan to shoot underwater then why bother with the sound. Shoot 38fps and set the project at 24fps you'll get cinematic look in slow motion.
I usually shoot 50fps with project set at 25pfs

Sometimes the sounds are important in slow motion, this applies more on the surface shallow stuff, jumping in. Water, shark bitting something.

 

[Kay Burn Lim]

I was the main underwater shooter for shows airing on Smithsonian Earth and other channels for the last couple of years. My producers always request 30fps (29.97) for the project and shooting at 60 if possible. I agree with Darek, shoot at 38 with the project set at 24. Motion will look smooth... probably more realistic than half speed. That's my plan anyway with my Epic-W....

Sounds really are not necessary for uw work. Much is available as stock online. However, if you truly need sound, you will need a hydrophone as the internal mic will probably pic up all sorts of sounds from the fans and gears. I also assume you will be using a rebreather if not all you will get are bubble noises. If more for surface work, splashes and similar stuff could be recorded externally and synced in post.

The one time I was asked to use a hydrophone was for whale sounds and dolphin clicks.... I asked my producer if they would rather have slow mo and simply purchase whale sounds and clicks from stock (there is no "lip synching" required lol). The idea was dropped pretty quickly

 

[Daniel Stilling]

When it comes to project base, 30fps is the 4:3 of frame rates...

 

[Rodrigo Violante]

Thank you so much! Actually makes total sense for the whales and dolphins.

For stuff like this I usually think freediving is the best, but you are right about rebreather, I didn't thought about that one and to be honest they are still pretty risky to use, and I can't use my full face mask.

On Monday I have a meeting with some sharks, lets see how the w reacts.

I was the main underwater shooter for shows airing on Smithsonian Earth and other channels for the last couple of years. My producers always request 30fps (29.97) for the project and shooting at 60 if possible. I agree with Darek, shoot at 38 with the project set at 24. Motion will look smooth... probably more realistic than half speed. That's my plan anyway with my Epic-W....

Sounds really are not necessary for uw work. Much is available as stock online. However, if you truly need sound, you will need a hydrophone as the internal mic will probably pic up all sorts of sounds from the fans and gears. I also assume you will be using a rebreather if not all you will get are bubble noises. If more for surface work, splashes and similar stuff could be recorded externally and synced in post.

The one time I was asked to use a hydrophone was for whale sounds and dolphin clicks.... I asked my producer if they would rather have slow mo and simply purchase whale sounds and clicks from stock (there is no "lip synching" required lol). The idea was dropped pretty quickly

 

[Kay Burn Lim]

No worries buddy. Another workaround for recording basic audio could be to use a GoPro attached to the camera housing? You won't be able to sync the sound if shooting for slow mo though... it would sound strange (but worth a try if only slowing things slightly).
At least you would probably get clearer audio than relying on the internal mic though the large housing

Thank you so much! Actually makes total sense for the whales and dolphins.

For stuff like this I usually think freediving is the best, but you are right about rebreather, I didn't thought about that one and to be honest they are still pretty risky to use, and I can't use my full face mask.

On Monday I have a meeting with some sharks, lets see how the w reacts.

 

[Simon Buxton]

I think it will depend on what market you are intending to sell to. If going for US networks then I believe as Kay mentions then you'll want 30/60p, BBC likes to be based on 25fps but these days are less strict as almost all documentary work is done in slow-mo, and they typically want as many frames as possible.

Depending on what housing you use, you may be able to squeeze an old iphone in there hooked up to the hydrophone and leave it recording for the whole dive if just wanting sound bytes.

For my full face mask i've tried the base station on the surface and the input on A7sii, both of which were not as good as directly on the RED - and you can use certain FFM on a rebreather, just FYI.

Reef Photo have all the hydrophone parts in stock, just a short drive up the coast from you.

 

[Björn Benckert]

I'm trying to shoot at the maximum quality possible for an underwater video so I have 2 options (actually 3) 24fps or 30 fps and I can maybe put 38fps at 8k WS.

I know at 24fps it gives you a more film alike experience, but my fear is the slow motion, if I decided to go 24fps I can't slow motion at all, so I'm wondering what issue will I have if I shoot at

38fps (project base 38 fps, so I can have sound) and then playback at 24fps.

What will be my biggest disadvantages, is it only the motion blur? because I will have to be at 38fps and 1/38 or 1/76 of shutter speed?

Really sorry for this amateur questions I'm sure here I'm asking the most pro audience but I don't believe I will get a better answer anywhere else.

Thanks

Rodrigo

Why not go double up and shoot 48p 360 shutter and then you have both slomo and 24p. You then have correct motion blur at 24p if you speed up your material by 200% with no frame interpolation. Then if you need slo-mo sure it´s shot 48p 360 shutter but at slo-mo the shutter speed is far less important and will not be that noticeable.

If you want sound you just set your project frame rate to 48p and record sound and then deal with the speed up of the images or slowdown of the sound in post .