Motion Cadence

[sam]

how does slowmo relate if at all to the vague term motion cadence? it seems like 9 out 10 "cinematic" youtube camera "tests" are now done in slowmotion. is there any correlation?

 

[webrunner5]

13 hours ago, mercer said:

Chicken Treat sounds about as real as motion cadence and cinematic. Lol. 

Shit I think you are right, LMAO.

[KnightsFan]

4 hours ago, sam said:

how does slowmo relate if at all to the vague term motion cadence? it seems like 9 out 10 "cinematic" youtube camera "tests" are now done in slowmotion. is there any correlation?

 

Many cameras read out fewer pixels when doing slow motion, and have less rolling shutter in slow motion (fewer pixels to process = faster processing per frame). I don't know if that's WHY youtubers do "cinematic" tests in slow motion.

This might also be part of the reason @Papiskokuji prefers the RX10 motion vs the a7s II.

[Mark Romero 2]

19 hours ago, jonpais said:

?. God, I’d kill for some fish and chips now. Not a thing here in Vietnam, I guess.

Yeah, back when I lived in Thailand in the 90s for 4 years, I would have killed someone for tacos.

[kye]

I thought that YouTubers used slow-motion because it looked 'better', which may be mostly that real-life needs all the help it can get to look nicer, and the slow-motion smooths out the camera-shake.

So, as contenders we currently have:
- line-skipping when reading the sensor (this wouldn't be to do with motion, it would be to do with how each image was rendered, but might be something that looks 'nicer')
- less rolling-shutter (shouldn't apply much to static tripod-shots)
- jitter in frame rate (variation in how far apart the frames are exposed)
- shutter angle

I have a vague memory of reading that some cameras take a small amount of time to open or close the shutter, kind of like it faded in, and this meant that the edges of moving objects weren't as sharp.  I'm not sure exactly how this would be accomplished (I know very little about shutter design) but it sounds simultaneously like something that could be true in expensive cameras, or could be 'alternative internet facts'.

On a more philosophical note, my personal view is that every technical aspect of filming will have an artistic implication, and behind every artistic impression there is a something tangible that we can isolate and measure.  One of my goals is to understand what technical / specific things are behind the artistic things, so I can explore them and then use them to create a finished product where more of the choices I made are coherent with the overall feel I was going for.  
For example if we want something to look happy we use brighter more saturated grading because that supports a happy vibe, or if we want people to be on edge then we can have extreme close-ups with wide-angle lenses to distort the image which supports the feeling of un-ease.  I read that in a recent war movie the director used a 90 degree or 45 degree shutter on action sequences as it showed explosions as being full of chunks of people instead of just being blurry and also made it feel more real and less 'cinematic'.
I'm hoping we can learn something tangible about motion cadence in this thread.

[mercer]

1 hour ago, kye said:

I thought that YouTubers used slow-motion because it looked 'better', which may be mostly that real-life needs all the help it can get to look nicer, and the slow-motion smooths out the camera-shake.

So, as contenders we currently have:
- line-skipping when reading the sensor (this wouldn't be to do with motion, it would be to do with how each image was rendered, but might be something that looks 'nicer')
- less rolling-shutter (shouldn't apply much to static tripod-shots)
- jitter in frame rate (variation in how far apart the frames are exposed)
- shutter angle

I have a vague memory of reading that some cameras take a small amount of time to open or close the shutter, kind of like it faded in, and this meant that the edges of moving objects weren't as sharp.  I'm not sure exactly how this would be accomplished (I know very little about shutter design) but it sounds simultaneously like something that could be true in expensive cameras, or could be 'alternative internet facts'.

On a more philosophical note, my personal view is that every technical aspect of filming will have an artistic implication, and behind every artistic impression there is a something tangible that we can isolate and measure.  One of my goals is to understand what technical / specific things are behind the artistic things, so I can explore them and then use them to create a finished product where more of the choices I made are coherent with the overall feel I was going for.  
For example if we want something to look happy we use brighter more saturated grading because that supports a happy vibe, or if we want people to be on edge then we can have extreme close-ups with wide-angle lenses to distort the image which supports the feeling of un-ease.  I read that in a recent war movie the director used a 90 degree or 45 degree shutter on action sequences as it showed explosions as being full of chunks of people instead of just being blurry and also made it feel more real and less 'cinematic'.
I'm hoping we can learn something tangible about motion cadence in this thread.

You’re well on you way. Just understanding why you would use certain grading and lenses is great info to have. The war film was Saving Private Ryan and yes Spielberg is a master for shooting those scenes that way.

As far as motion cadence, I’m sure there is a tangible reason but we aren’t privy to each camera’s special sauce to discern the exact reason. But you can quickly know it when you see it and which cameras have good cadence and which don’t. I’ve noticed that exact frame rates may help... so true 24p instead of 23.976... slow motion as well... lol. 

You have 3 cameras, don’t you? The XC10, a 700D and a 700D with Magic Lantern? You could always run some tests and do a motion comparison by messing with settings in ML?

[kye]

19 minutes ago, mercer said:

You’re well on you way. Just understanding why you would use certain grading and lenses is great info to have. The war film was Saving Private Ryan and yes Spielberg is a master for shooting those scenes that way.

As far as motion cadence, I’m sure there is a tangible reason but we aren’t privy to each camera’s special sauce to discern the exact reason. But you can quickly know it when you see it and which cameras have good cadence and which don’t. I’ve noticed that exact frame rates may help... so true 24p instead of 23.976... slow motion as well... lol. 

You have 3 cameras, don’t you? The XC10, a 700D and a 700D with Magic Lantern? You could always run some tests and do a motion comparison by messing with settings in ML?

Ah yes, Spielberg and Saving Private Ryan.  A memory is a good thing when it works

Actually, one of the main challenges I have is that I don't really know it when I see it.  I think my perception is a mixture of being unsensitised to these elements, and is also untrained.  A big part of learning for me is learning to see.  I can often see a difference between two different finished products (eg, I know I prefer the production of Peaky Blinders and The Crown to most other shows) but when I try and isolate the individual variables I'm often just left with two things that look the same to me.  In a way that's why I'm hanging out on forums like this so much - I'm trying to learn what other people see and what the technical thing is behind it.

Yep - my current kit contains XC10, 700D with ML, and iPhone 8 with ProCam (which provides full manual controls).  I also have other much lesser cameras, but I suspect they're not high enough quality to be useful.  What settings would you suggest I play with?

[IronFilm]

20 hours ago, jonpais said:

Around seven years ago, there was an interesting discussion about the motion cadence of the GH2 over at Personal View, where cadence is simply described as the interval between frames and as unrelated to the type of shutter, as best as I can understand it anyway. Stuttering would be the result of an uneven interval between frames. Or something like that, it's too technical for me.

So would having a box for genlock make an image more "cinematic"?

[kye]

18 minutes ago, IronFilm said:

So would having a box for genlock make an image more "cinematic"?

I just took a quick look over that thread and saw a lot of discussion about how the codec can introduce jitter / stuttering into something that didn't have them before.  If that's true (and assuming I read it right) then it might be that the signal path might matter just as much as the capture device.

Technology is normally very good at things like this, with error rates in the realm of parts-per-million (ie, only varying by something like 0.00000001%).  The problems come in when there are secondary effects of such a small error that end up as something we're very good at perceiving.
For example, in digital audio jitter can be quite audible despite being a very small variance.  The reason it becomes audible isn't by hearing it directly (you don't hear the music speeding up and slowing down!) but because the timing is used to convert digital to analog and small timing variations cause harmonic distortions, which even if they aren't audible by themselves then cause intermodulation distortion, which are both things we are quite attune to hearing, so the problem is that these small timing errors can have audible knock-on impacts.  
In terms of frame rates though, I can't think of any knock-on impacts we'd be more sensitive to, or where the impact would be exacerbated.

[jonpais]

I think it’s the EOSHD server.

I would love to see the look on any one of the camera manufacturer representatives’ faces if a YouTuber were to approach them and ask about their crappy motion cadence. I would pay to see that.

[mercer]

42 minutes ago, kye said:

Ah yes, Spielberg and Saving Private Ryan.  A memory is a good thing when it works

Actually, one of the main challenges I have is that I don't really know it when I see it.  I think my perception is a mixture of being unsensitised to these elements, and is also untrained.  A big part of learning for me is learning to see.  I can often see a difference between two different finished products (eg, I know I prefer the production of Peaky Blinders and The Crown to most other shows) but when I try and isolate the individual variables I'm often just left with two things that look the same to me.  In a way that's why I'm hanging out on forums like this so much - I'm trying to learn what other people see and what the technical thing is behind it.

Yep - my current kit contains XC10, 700D with ML, and iPhone 8 with ProCam (which provides full manual controls).  I also have other much lesser cameras, but I suspect they're not high enough quality to be useful.  What settings would you suggest I play with?

Idk, if you think you’re desensitized to that, then I guess I would start with something simple like looking at two shots of the same exact footage with one shot in 24p and one shot in 30p. Use the 180 Degree rule for both to keep the other variables consistent (so 1/60th shutter for the 30p footage and 1/48 or 1/50 for the 24p footage) See what you notice.

If you notice no difference whatsoever, then you are probably 25 or under and it won’t matter because you’re the future and all of this stuff will be antiquated in 10 or 20 years when you guys are running the world. 

[sam]

https://cml.news/g/cml-raw-log-hdr/topic/skintones_are_they_affected/16427778?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,16427778

this gets into motion cadence a bit.  

even with gimbals, ibis, etc...slowmo continues. i think youtubers love slowmo in their cinematic whatever because it somewhat nullifies  "motion cadence" issues on the camera side.

 

[mercer]

That definitely makes sense, even with 24p footage, I direct my actors to move slower and more deliberate.

[jonpais]

i

[kye]

9 minutes ago, mercer said:

Idk, if you think you’re desensitized to that, then I guess I would start with something simple like looking at two shots of the same exact footage with one shot in 24p and one shot in 30p. Use the 180 Degree rule for both to keep the other variables consistent (so 1/60th shutter for the 30p footage and 1/48 or 1/50 for the 24p footage) See what you notice.

If you notice no difference whatsoever, then you are probably 25 or under and it won’t matter because you’re the future and all of this stuff will be antiquated in 10 or 20 years when you guys are running the world. 

I will do this and try as hard as I possibly can to see no difference..  I'd take being 'motion cadence blind' and under 25 any day!!

[sam]

6 minutes ago, mercer said:

If you notice no difference whatsoever, then you are probably 25 or under and it won’t matter because you’re the future and all of this stuff will be antiquated in 10 or 20 years when you guys are running the world. 

yes.  

1 minute ago, kye said:

 I'd take being 'motion cadence blind' and under 25 any day!!

me too! 

[jonpais]

Years ago, Terenax published a paper on their video processors for de-interlacing video and problems with motion cadence, but I can’t find any technical papers related to progressive video.

Terenax

[mercer]

Interesting, I really think all-i frames probably make a difference as well.

[TwoScoops]

1 hour ago, mercer said:

Interesting, I really think all-i frames probably make a difference as well.

I agree, this is a huge part of it! 1DC, BM, 5D Raw all have that in common and are considered to be good in this area. 

[mercer]

3 minutes ago, TwoScoops said:

I agree, this is a huge part of it! 1DC, BM, 5D Raw all have that in common and are considered to be good in this area. 

Yup, even the 200mbps all-i 1080p in the FZ2500 has a really nice motion cadence to it... way better than the Long GOP 4K files do.