What is Motion Control?

Motion Control means motion that is very accurately, computer controlled, using electrical motors. In the film and Television industry, this has come to mean a field of filming where the camera movement is controlled by a computer so that the motion of the camera, in the studio or on location, can be repeated again and again, for the generation of special effects. It is essentially a camera robot, but in the industry these technical pieces of machinery are referred to using the more creative sounding term “motion control rigs”.

Why use Motion Control?

By being able to program and repeat the camera movement very accurately one can suddenly do a whole variety of special effects shots, that are either impossible to do without Motion Control or one can only do using a non-moving camera (known as “locking-off” the camera). But to achieve really natural and stunning looking shots one normally wants the camera to move during a take or follow a subject or some action, and that is why Motion Control is vital.

Take one of the simplest special effects shots one could try and do, such as a scene showing a man walking along a street and gradually disappearing into thin air as he walks. This is done by doing 2 takes. The first one contains the man walking in the street and the second one is just the street. Then during the editing process one starts with the man walking and then gradually mixes to the second take, where the man isn’t, so it appears the man has gradually vanished into thin air. This maybe simple to achieve if the camera never moves, but as soon as the camera is moving this shot is impossible without Motion Control as the 2 takes would never match in perspective and speed and so a mix would never “mix”. This would be just one of countless different types of shots requiring Motion Control.

I don't do special effects, why use a Motion Control rig?

A Motion Control rig is designed to be very easy and quick to program in the desired move. Once the move is programmed it can be repeated again and again, at different speeds, or with adjustments, with complete accuracy. This means that if one is shooting an object that is very difficult to light properly (due to shape, reflections, lens flares etc.), such as a car, one can program in the move quickly and then spend all one’s time on setting up the lights, moving slowly back and forth through the move to check how it appears through camera, without worrying if the move will be the same next time the camera is moved (note: traditionally cameras are moved by hand, using many “grips” – large men – so the motion will be different every time without Motion Control.

I do mostly live-action shooting, why use Motion Control?

Again, because the rig will repeat the movement very accurately, including focus-pulling, zooms, and even control lights and moving set props, one can concentrate on just the actors and making sure they do their action correctly, without worrying if the grips will do the right move on the next take. This also saves money by saving on the required personnel and time taken for a shot.

Particularly when using high income actors (“talent”) it may be desirable to program in the camera movement beforehand, and then when everything is ready, get the talent in, and shoot straight away, so that they spend as little time on set as possible.

How do you program a move on a motion control rig?

Over the years many different methods for generating moves have been developed for different applications. These can be roughly divided into 3 different methods:

1) Directly entered move. Typically one has control of the rig remotely, and on simply move the rig to the desired start position and presses a button to store that position. Then one goes to the next point one wants the rig to be at, and stores it. Then the rig is moved to the final position, which again is stored. This gives a simple 3 point move (a move may have as many points as one desires but for most shots, between 2 and 5 points are required). The computer software joins these 3 points with a smooth curve. All one specifies is how many frames should be taken and at what camera speed and the move is now ready to shoot.

2) Mimic move. Special hardware exists that allows one to move the motion control rig by actually pushing it much like a normal dolly or crane, or use remote hand-wheels to control the movement and record any motion made. Once recorded it can be played back at any speed like any other move. Directors often make use of this when wanting a “human” fee to the move, or when shooting actors or animals that may not move or behave exactly as required.

3) CGI Import. One can design moves on CGI packages, such as Softimage/Xsi and Maya, and import them directly to the motion control rig, so even the most complex camera paths can be executed exactly.

How long does it take to program in a move?

This really depends on the complexity of the move, but storing the positions the camera should go through and then running the basic move is a matter of minutes. Then adjusting it slightly and getting the exact move desired may depend on the lighting, subject matter, and even the director

How long does it take to set up on location?

Assuming there is stable surface on which to lay the track, the rails can normally be laid down, levelled, and the Milo build and ready to shoot in 45-60 minutes. In many cases the Milo does not need to be put into flight cases for transportation and this process can then be speeded up.

What is the benefit of using Motion Control when it comes to the post-production?

Post production relies heavily on having good original takes. Motion Control is often the unsung hero of effects, enabling scenes from the real world to be seamlessly multi-layered and combined with computer graphics and digital effects. Being more of a production tool, many people see the glitz and praise given to powerful post production graphics packages, and miss the vital concept that without the motion control footage, these high end effects could not exist.

Additionally, because the camera trajectory and perspective is very easily exported from the rig to the post-production tools, CGI backgrounds and fore-ground elements can be very easily and accurately added.

How accurate is Motion Control?

Using electronic devices known as optical encoders on all the motors, the movement of every axis of the motion control rig is measured down to micron level, far below movement visible to the eye or film This is so small, that you are more likely to have errors due to the metal of the rig expanding and contracting under bright lights, due to heat, than because of motor position measurement

How can I best incorporate Motion Control with CGI?

There are several tools available for transferring data between Motion control rigs and CGI programs. We currently have tools available to interface to Maya, Softimage/Xsi, Alias Power Animator, Lightwave and Flame. Tools are built into Mark Roberts Motion Control to import and export data, and to aid in alignment of CGI to live footage.

What is Target Tracking?

Target Tracking is a feature developed by Mark Roberts Motion Control, over 20 years ago, that allows the camera to move along an exact path through space and follow a target, stationary or moving, perfectly, regardless of the complexity of the rig. This make it very easy for director and rig users to get the camera to follow the exact path they desire without having to work out what each axis (motor) has to do to achieve the path, or stay focused on the target.

What is Scaling?

Scaling is a feature, exclusively found in Mark Roberts Motion Control rigs that allows any camera movement to be automatically scaled up or down, moved or rotated. This allows such special effects as mixing miniature models or backgrounds, with live action talent making the 2 appear the same size, or rotating move to make it appear gravity is acting in numerous directions and people are simultaneously walking on the floor, walls and ceiling.

How does Motion Control relate to pre-visualisation?

The field of pre-visualising shots during the design and planning stage of shoots and entire movies, is rapidly taking hold and growing. By pre-visualising a move everyone has the agency’s, producer’s, or director’s view of what the finished shot will look like. This not only stops costly mis-understandings, but also aids in preparation for the shot, by allowing set designers to see how big the set needs to be, or where it should be positioned or built, by allowing cameramen to know which lights they will need and where, and so on, saving time and ultimately money.

Now any move designed as such can then be directly imported into the rig, so that the camera move on set will be identical to the pre-visual.

How fast do rigs go?

Rigs are continually being upgraded to move faster. Currently a Cyclops or Milo can move at 3 metres per second (depending on options), and because the camera is on the end of a long arm which can rotate and extend, in total the camera can reach speeds close to 5 metres per second.

Can I record moves manually?

Yes. Using “Grip-Sticks” you can actually push rigs around by hand and they will record the movement and then repeat it back as often as you need. You can also use remote hand-wheels to control individual axes much like the hand-wheels controlling Pan and Tilt on a manual dolly. We can this facility mimic. You can also re-program the movement of some axes and manually record or adjust the movement of others, which is often used when filming animals that don’t necessarily hit there marks correctly.

How many people does it take to build or take apart a Milo?

Due to its lightweight aluminium construction (a Milo weighs only 700kg), and ease of assembly, most rigs go out with just an operator and a technician/helper. Except for the main arm, which requires at least 3 people to assemble, everything can be put together using just 2 people. Of course the more people the easier the work!

Can I do animation?

Motion Control has its roots in the animation field and all Mark Roberts Motion Control rigs and software has been designed with animation in mind. Academy Award winning films such as “Wallace and Gromit” were made with Milos. One can do both stop-frame animation and moving step (sometimes called go-motion) animation to achieve motion blur, and seamlessly integrate animation with live footage, or computer graphics. Time-lapse photography is also standard.

What are model movers?

Model movers are motors that control some aspect of the set being filmed, and are completely synchronised to the movement of the rig. You may have a model mover to rotate a car, or another to move a miniature model. Mark Roberts Motion Control manufacture a variety of standard and bespoke model movers.

What cameras can I use?

Most film and video cameras can be accommodated by our Motion Control rigs, depending on size and weight. Standardly we use Fries Mitchells, Mitchell S35s, as these are considered the best cameras for motion control. But was also accommodate Arri435s, Arri IIIs, Moviecam Compacts Panavision, broadcast video cameras and camcorders, and even HD (High Definition) video cameras.

How much do the rigs weigh?

A Milo weighs only 700kg. a Cyclops, which is purely a studio based system, weighs 2 tons, and has built in hydraulics to move itself around the stage to different locations. The Juno weights about 350kg.

I have heard that Motion Control is unreliable?

At Mark Roberts Motion Control reliability is a key issue in all designs. Many years ago motion control got a bad name in several countries, due to the unreliability of equipment, due to bad designs and the general quality of various “home brew” motion control systems made quickly and cheaply to fill someone’s individual requirements.

We don’t compromise on the quality of parts and regularly make certain any reported reliability issues are resolved quickly and totally. That Is why our Milo and Cyclops rigs are the number one motion control systems in the world.

What is Camera Vari-Speed?

This feature allows the camera to speed up and slow down during a take, with the iris or shutter automatically compensating for the changes in exposure. When the take is played back at live-action speeds, it appears the action is slowing down or speeding up seamlessly

What is Flair? Why use Flair instead of other software?

Flair is the software and electronic hardware developed by Mark Roberts Motion Control for motion control use.

Mark Roberts Motion Control is the only company in the world that develops both the rigs and the software, so the two are very closely integrated, giving greater versatility that cannot be offered by any other software for motion control. It contains features that have evolved from the company’s involvement in the industry for over 20 years Once “convert” to the software, many wonder how they would manage without it.

Do you make custom systems?

Yes. We produce other systems, designed per requirements.

What is mimic?

Mimic is a feature that allows the rig to be pushed or controlled remotely, and any movements so made can be recorded and repeated again and again. Additionally, the data from such moves can be exported to CGI, eliminating the need for tracking?

Doesn't tracking eliminate the use of Motion Control?

Tracking allows the camera position in space to be calculated from only having 2D footage. Once the camera position or path is known, CGI foreground and background elements can be easily added to the live-footage. Traditionally, getting the camera path calculated and sent to CGI packages would have been done using Motion Control, by first shooting the take using a Motion Control rig. Since the rig always knows the camera position in space accurately, it is very simple to transfer the data to CGI packages.

Tracking does sometimes eliminate the need for motion control, but in very few shots, and in most cases compliments its use. As soon as one needs multiple-pass shots, motion control is the only solution. Also, tracking relies on having fixed points in the background from which to work out the camera trajectory, and if these don’t exist, or are hard to see, because the picture doesn’t stay in focus, or the points don’t stay in shot, or there are no fixed points (such as when shooting someone on green screen), then tracking will not work.

In fact, tracking adds a new field to motion control, as one can now take old existing footage and using tracking, work out the camera trajectory, feed the camera path to a motion control system and add a new live-action foreground element. This has quickly been utilised by the film industry, and Mark Roberts Motion Control rigs can now interface to SceneGenie and BouJou training packages

Why should I buy a Mark Roberts Motion Control system and not another cheaper product?

That’s simple. The main reason is rigidity. Motion Control is nothing without repeatable, frame-accurate, and “wobble” or shake free moves. If you have footage that wobbles, or the takes don’t quite match, the cost of trying to do any post-production on them will sky-rocket. If a rig comes to a stop or accelerates and is wobbling due to these changes, the footage will show this.

At Mark Roberts Motion Control, we don’t compromise on component quality. All our bearings, motors, ball-screws, gears and pinions are precision machined and aligned to give you the most rigid shot possible, thereby saving on post-production costs. It is no good buying motion control equipment if it shakes. Our equipment is the best, which is why we have the best selling motion control systems in the world.