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class="style10" Filming A Zoetrope

>Published : 15th January 2006

>Has anyone ever filmed a zoetrope? Is it possible to get the same effect you would get as if you were looking at it 'live'. I have a script with a zoetrope scene (POV). Do I need to control its speed precisely in order to 'synch it with my camera?

>Thanks for any shared experiences.

>Menno Westendorp
DoP
Amsterdam


class="style11">>Has anyone ever filmed a zoetrope? Is it possible to get the same effect >you would get as if you were looking at it 'live'.

>I have, Praxinoscope as well.

>It's inherently a bit "flickery". In any case with your mirror shutter camera you should get a sense of what speed to spin it at, yes you can "sync" it.

>I actually shot with an electric Bolex EL (so I could use the 6mm Aspheron on 12.5-100 zoom & then pop that off go into (stay in, actually) macro, made life simple) so I was going on intuition re flicker but I guess we spun it at some different speeds, it looked fine on screen.

>This was a collection of 19th Century 'Optical Toys' - Cool stuff!

>Sam Wells


>I did one of these a couple of years ago. It might work without syncing, but we didn't risk it.

>We came up with a record player - anyone remember those? Put the Zoetrope on top, and you have a turn table that is crystal-synced (the one we used was, at least) at 33 rpm & 45 rpm. With some metal math, you can figure out the fps needed:

>Imagine Zoetrope that has 10 slots
45rpm = .75 revs per second
Each rev has 10 slots
.75 X 10 = 7.5
Each second covers 7.5 slots
Sync speeds then are 7.5, 15, 30, 60 FPS

>Run camera with mag off and uses phase button, or speed controller to phase it up.

>It worked for us . . .

>Joshua Breckeen
Gaffer
Hertfordshire, U.K.


>I think actually it looks fine to see it phasing in and out, they pre-date the totalitarian concept of fixed frame rate playback

>Sam Wells


class="style11">>I think actually it looks fine to see it phasing in and out, they pre-date the >totalitarian concept of fixed frame rate playback

>lol !

>Well said, Sam.

>And I suppose a 'flickering' zoetrope would look more real, since, historically one did not run it by running at pre-determined 'persistence of vision' speeds.

>So really, most any speed would work .... unless you miraculously run it to be exactly OUT of phase with the camera.

>But what are the chances ?

>Duraid Munajim
DP, TO


class="style11">>We came up with a record player - anyone remember those? Put the >Zoetrope on top, and you have a turn table that is crystal-synced (the >one we used was, at least) at 33 rpm & 45 rpm. With some metal math, >you can figure out the fps needed :

>That's really clever! Well done.

>Bob Kertesz
BlueScreen LLC
http://www.bluescreen.com


class="style11">>I think actually it looks fine to see it phasing in and out, they pre-date the >totalitarian concept of fixed frame rate playback

>I can't agree with this.

>The phase-in phase-out appearance is an artefact of the two different frequencies (or frame rates). If the shot is intended to simulate what a real Zoetrope looks like when spun, then you need to avoid the phasing in just the same way as you try to avoid rolling bars when filming TV sets.

>>And I suppose a 'flickering' zoetrope would look more real, >since, historically one did not run it by running at pre->determined 'persistence of vision' speeds.

>Flickering isn't phasing. It's true the zoetrope would have been run "free", but if it was run at - say - 12 fps, I'd be shooting at 24, giving 2 film frames per zoetrope image, and a suitable amount of non-persistence of vision flicker. Agreed, if it slowed down to 10 or 11 fps, you couldn't reproduce the effect on film without introducing phasing - but that isn't what the zoetrope viewer would have seen.

>Dominic Case
Atlab Australia


>How about no shutter at all?

>Seems that that would be the most like a human eye. Foreground would be blurred in any case. Effective shutter speed would be based on slot length (in radians) and rotation speed. Of course, shutterless cameras are harder to come by.

>Fortunato

>Procopio
DP-NYC/LA


class="style11">> How about no shutter at all?

>Vertical streaking could be a problem.

>Ramping the shutter on a 435 could produce interesting
effects mind you.

>Tom Townend,
Cinematographer/London.


>Well, it certainly would be possible to synchronize the frame rate of the camera with the spinning of the zoetrope. All you need is a shaft encoder.

>This could be done using the hand crank option for the Arri 435, or the hand crank option for the Kinetta. Advantage of doing it digitally is that you can immediately tweak capture speeds.

>Jeff "too busy to play with it now" Kreines


>If it maintain a constant rate of rotation, it will appear to the naked eye to phase / flicker a bit , whatever you want to call it.

>Is the shot a scientific experiment, or subjective experience ? The idea of playing shutters against each other appeals to me.

>I would shoot a few frame / rotation rates, have fun, see what you like.

>Sam "used make an AR turntables run backwards, fun at parties, and
useful too" Wells


class="style11">>If it maintain a constant rate of rotation, it will appear to the naked eye to >phase / flicker a bit, whatever you want to call it.

>I mean if it doesn't maintain.

class="style11">>Ramping the shutter on a 435 could produce interesting effects mind >you.

>You sound like your on my side !

>Sam Wells


Thanks for all the info on filming a zoetrope. Especially Joshua,s simple but effective approach seems very useful.

To make things more complicated, the 'POV' shot of the zoetrope continues with a jib up and track back to reveal the rest of the scene. so a frame rate between 20-30 would be best. Also, does anyone think the width of the slots has an effect (besides exposure time)?

>Menno Westendorp
DoP
Amsterdam


class="style11">Also, does anyone think the width of the slots has an effect (besides exposure time)?

>The slots are what enable the whole illusion. Widening the slots significantly will increase the time the content is seen by your eye or camera, reducing the shutter effect and reintroducing the motion blur of the spinning image. Spinning the zoetrope faster will correct this, but then your content loop plays faster too. Could you shoot at a shutter angle narrow enough, or a frame rate high enough, that you could widen the slots substantially and not speed up the animation? Yes, but then are you any further ahead? The slots also ensure the registration of the content, making each subsequent "frame" appear in the same place as the previous one. The wider the slots, the more lateral wiggle you introduce.

>Has anyone visited the American Museum of the Moving Image in NY and seen the sculpture by Gregory Barsamian called "Feral Fount" that uses a strobe light as a shutter. Very cool, and where else can you play Space Invaders?

>Jordan Cushing

>Long time fan of the "wheel of the devil" and Toronto DOP


>It all depends on the 'look' you want.

>A 23 frame video camera can be a good tool for figuring out what sort of look you want. you can play with the zoetrope and see the result in real time.

>If the slots are perfectly timed and aligned with the film camera you will get the motion of the image, but probably miss the 'flicker' effect.

>Testing is a good thing.

>Marty Brenneis
Industrial Magician