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motion control and mixed frame rates


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hi all,

planning for a short film involving alot of motion control with different frame rates composited into the same shot.

because of budget, i'm thinking of going S16mm for savings in filmstock, but i'm wondering if there would be any drawbacks to shooting 16 over 35? mostly in regards to the frame rates composited into the same shot, i'm thinking arri srIII, would there be any image stability issues at high speed that may be noticible after being composited into a shot with another speed? plus, is there any issues using the srIII with motion control systems? this is will be my first motion control shoot, so ANY advice on working with motion control in general would be great...

peace

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hi all,

planning for a short film involving alot of motion control with different frame rates composited into the same shot.

because of budget, i'm thinking of going S16mm for savings in filmstock, but i'm wondering if there would be any drawbacks to shooting 16 over 35? mostly in regards to the frame rates composited into the same shot, i'm thinking arri srIII, would there be any image stability issues at high speed that may be noticible after being composited into a shot with another speed? plus, is there any issues using the srIII with motion control systems? this is will be my first motion control shoot, so ANY advice on working with motion control in general would be great...

peace

 

 

sorry guys, pls ignore this post, i put it in the wrong forum... sorry

btw, how do u delete posts?

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hi all,

planning for a short film involving alot of motion control with different frame rates composited into the same shot.

because of budget, i'm thinking of going S16mm for savings in filmstock, but i'm wondering if there would be any drawbacks to shooting 16 over 35?

 

Yes, there quite a few. Super 16 is a single perf format, and can only use single pin registration. 35mm uses double registration pins, giving far more stability - quite necessary when shooting multiple passes with motion control. Not to mention grain issues, which are significant when you're doing any matte/roto work. In fact, you'd be much better off using video with motion control than you would 16mm, for the same reasons ("perfect" registration, no grain).

 

Super 16mm is very good for many things. Visual effects/motion control shooting is not one of them. Of course, I was only a Visual Effects Supervisor for 9 years, so what do I know?

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HAHA, it would be two dumb mistakes for the day should i not take your advice (the first one being posting this topic in this forum...). even with DI would grain still be an issue? say one was to use the two regestration pin panavision 'elaine'? though i dont know if budget would allow, but theoriticaly would that be the same stability as 35mm cameras?

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In fact, you'd be much better off using video with motion control than you would 16mm, for the same reasons ("perfect" registration, no grain).

 

Since he mentioned that he'd be shooting at different frame rates, that would probably limit him to something like the Panasonic Varicam.

 

Super-16 only has perfs on one side, so it makes no difference whether you use a Panaflex Elaine versus some other high-end Super-16 camera.

 

Aatons have a good reputation for stability, though you still may end up stabilizing your footage in post before compositing. The SRIII probably would be similar to an Aaton.

 

Maybe you should shoot a test before proceding?

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I'm mostly curious as to how you can afford motion control if you can't afford 35mm. Because man, if there's something affordable I don't know about, I'd love to hear it. Everything I've ever seen, though, is that motion control is extremely expensive in any form.

 

i dont know how much i can divulge, but the director is just graduating from the beijing film acadamy (beijing china that is) and they have a motion control unit there, am trying to find out which system, but as he was a star pupil, he has access to it... we are looking around about operators now, but u didnt hear it from me!

what if we were to use double perf 16mm film? as a cameraman friend just shot a s16mm anamorphic shoot here in china using the panavision 'elaine', specificaly because of the double registration pins.

photosonic would probably be the direction (should we go 16mm) as we'll need to get to at least 150fps with double reg pins.

any more thoughts on that? or even better, does anyone know where to get photosonics in china???

thanks guys..

Edited by matt wakai
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what if we were to use double perf 16mm film?

 

Well, by definition, you can't shoot Super 16mm using double perf film. So you would have to crop for a wide screen aspect ratio, assuming you want something other than 1.33:1. That amplifies the grain issue, and also amplifies any extraneous movement you do encounter.

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- Whenever I've been involved in motion control shoots (at the now defunct Cell studios in London) it was always on 35mm. The only time 16mm was used was when a 16mm photosonics camera was operated by me to shoot some high speed shots of glass breaking as an element to composite in with the 35mm work...

 

Motion Control by it's nature can be a tedious procedure and requires a lot of planning a good experienced dop to pull it off...

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As mentioned before, 16 is not ideal for muliple passes because it does show significantly more weave than 35, even after transferring through a spirit. Also due to the high grain size, stabilising is not as accurate because the grain effects the trackers. Also, subtle stabilising inherently causes softness to be added to the image to a lesser or greater degree, depending on the software used.

 

I would really, really recommend 35mm for your project. Maybe 3 perf would help a bit with cost, assuming you could get a camera that supported the frame rates you need and that you were not going directly to theatrical print (which would then need a 3 to 4 perf optical process).

 

David Cox

Baraka Post Production

www.baraka.co.uk

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Could you perhaps use short ends or medium ends to save on cost? IDK how long your individual motion control shots would be, but perhaps you could get some savings with shooting 35mm for just a brief segment. What percentage of the total film will need motion control?

 

Frankly, if you're only budgeted to use 16mm, how can you afford what effectively amounts to TWICE the normal shooting ratio with motion control? Maybe not double, but you do have to do a couple of takes of the pass without the elements in it too. I've heard the track can "slip" sometimes too, so that necessitates more than one take for safety's sake.

 

Bear in mind I've never worked with any sort of motion control, or a Panavision Elaine, this is just from what I've read. There are some very interesting shots on motion control in ASC magazine.

 

May I ask why you feel the need to shoot high speed motion control instead of just sticking to 24 fps?

 

~Karl

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May I ask why you feel the need to shoot high speed motion control instead of just sticking to 24 fps?

 

~Karl

 

the director wrote a story wanting to take advantage of the motion control unit at his school, basically there will be lots of shots where the hero is interacting with an environment going 3/4 faster than he is, and then the other way around where everyone else sees him at 1/4 of their speed. its not so much that we are only budgeted for 16mm, but being a low budget short, any savings (if not compromising image quality too much) are being looked into. but using 35mm just for the motion control sounds like a good alley to go down.

thanks everyone so much for help so far! will be checking back regularly for more much needed guidance!

peace

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Dude, you really need to shoot a test before assuming that you can just do something. The difference between 1/4 and 3/4 is three times as fast, and basically you have a limited range of frame rates to choose from: too slow and not enough action is visible to tell the story (unless you load the frame with tons of subjects and action, but then that dilutes the impact on your main character) - too fast and the story drags and becomes equally unwatchable. What you really need to do is get this project out of the realm of ideas (Hey! My Mom can make costumes! etc.) and figure out what is going to be workable.

 

Try this: shoot some regular video and play with frame rates in Quicktime (I.E., convert the video to single frames, then use PhotoShop to delete or multiply frames) - it will quickly become obvious, even with fake over and undercranking, what is right and not right for your project.

 

Then you can figure out what format, camera, etc. to shoot it with.

 

My 2 cents)

Edited by Stuart McCammon
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The difference between 1/4 and 3/4 is three times as fast
He said 3/4's faster and 1/4 slower - relative to '1' and not each other

 

ie. 3/4's = %75 percent faster (not a factor of 3)

 

and 1/4 slower - ie. %25 slower (a factor of 4 this time)

 

They should really be the reciprocal of each other - but hey, its the movies!

 

--I've opened my mouth and got things wrong in the past, apologies if I've done it again :rolleyes:

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He said 3/4's faster and 1/4 slower - relative to '1' and not each other

 

ie. 3/4's = %75 percent faster (not a factor of 3)

 

and 1/4 slower - ie. %25 slower (a factor of 4 this time)

 

They should really be the reciprocal of each other - but hey, its the movies!

 

--I've opened my mouth and got things wrong in the past, apologies if I've done it again :rolleyes:

 

It's probably easier to describe relationships of speed as a scale factor or percentage. 75% faster is much easier to visualise mentally than 3/4's faster. So if normal speed is 24fps, the first instance would require shooting the hero at 24fps and the background at 18fps. And the reverse would see the background get shot at 24fps and the hero at 96fps.

 

My feeling is that the speed differences should be the same factor, so the background is 4 times faster (6fps) in the first shot and the hero is 4 times (96fps) slower than the background in the latter shot.

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I just got off a motion control shoot with Ben Butin. He told me that he had used other formats but now would only do 35mm using a Mitchell camera package for registration reasons. I don't know the details but he has been doing motion control for quite a long time.

 

www.benbutin.com

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What you really need to do is get this project out of the realm of ideas (Hey! My Mom can make costumes! etc.) and figure out what is going to be workable.

 

My 2 cents)

 

thing is, we are still way away from shooting, and we are still working with ideas, the reason why i asked is to see if someone could put me on the right track as we dont wanna test 16mm cameras if alot of people recomend against it, limited budget so dont want to test systems that are known to be unreliable.

 

its not gonna be like everything is slow or everything is fast in the one shot, there's always gonna be an element at normal speed. doing lots of research and lots of talking to experienced people is helping, but testing will come later.

 

we may need a costume maker dude! when is she availble? ;)

peace

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