CAMERA INTERFACING

Arri Alexa

Motion control rigs can be used with a large variety of Film and Digital cameras, as well as 3D Stereoscopic rigs. Apart from the consideration of the physical size of the camera package and whether it will fit onto the rig, there is also the availability of suitable interfacing to or from the camera, which determines the suitability of the camera for use with a motion control rig. The list of cameras used with motion control is fairly unlimited and includes all well known professional and prosumer cameras from manufacturers including Arri, Panavision, Red, P+S Technik, Photosonics, Vision Research, Nikon, Sony, Panasonic, Mitchell, etc.

Synchronizing and “You can fix it in Post”

Motion Control is used for a variety of reasons and some cameras and lenses are more suitable than others for specific shots. For example, stop-frame animation is a little difficult if your camera can’t take a single frame, and like-wise trying to do repeat passes at different speeds can be challenging in post if your camera only shoots at 25 FPS.

Arriflex 435 Xtreme

With the exception of shots where the motion control rig is being used for its ability to accurately follow a path but not necessarily to composite multiple passes together (for example, a product shot or macro shot which just requires the rig to follow an exact path for perfect lighting), the exposure of the camera and the motion of the rig have to be perfectly synchronized. The reason for this requirement for synchronization is because when the motion control rig shoots multiple passes it is important that the exposure on each take happens at exactly the same point every time. If they were not then when you have two different takes and try to composite them together the positions may be different by up to one frame. Obviously, if the camera is not moving very quickly then this difference in exposure position will not have much effect, but if the camera is panning quickly, say 2 degrees every frame then a difference of up to one frame would mean a difference of up to 2 degrees between the takes.

Red Epic

There are some less reputable companies or operators who say this is not important, or that camera vibration is not important, because “you can fix it in post”. At MRMC, synchronization and vibration are considered important because firstly, sometimes fixing it in post is not possible and secondly, why would you want to spend time and money fixing it in post when it is possible to get it right first time. That is why we like to inform clients of which cameras can be used for which purpose and what the limitations are so they can choose the right camera for the task of motion control. Not all cameras have synchronization facilities, whether in the form of an output or an input. Again, this lack of synchronization may be fine for the shot being created or it may not, depending on the application.

Nikon D5Speeds and Vari-speed cameras

While years ago most video cameras could only shoot at PAL or NTSC speeds and film cameras were needed for shooting at non-video speeds, much has changed with the revolution in digital cameras, and many cameras can now shoot at different speeds. Synchronization is just as important when shooting at any of these “other” speeds. Additionally, some cameras can change the shooting speed while filming to create effects of slowing down or speeding up the action. For this to work with motion control, the motion control rig also has to speed up or slow down with the camera speed. It is important to note that while some cameras can do Vari-speed filming, not all of them have a method to synchronize to their changing speed or for the motion control to control the speed of filming. Many video cameras that offer vari-speed only have a video output to synchronize to, and since video signals do not vary in speed, there is no way to synchronize to such video cameras. Many high end digital cameras, such as the Alexa and Phantom cameras do though have a separate output that can be synchronized to as well as a video output.

Panavision - Genesis

Additional hardware

Some cameras can offer good synchronization or even offer the motion control full control of its functions but require additional hardware to do so. One example is the Arri 435 Advanced/Extreme film camera. It allows the motion control software full control of the shutter and shutter angle so that one can achieve excellent vari-speed moves not easily achievable with the majority of other cameras. But the camera requires a “moco option” from Arri, which plugs into the camera to be able to do this. Another example is the Phantom high speed camera. It has a pulse output from the camera that can go to the motion control rig to allow it to synchronise. But the pulses from the camera are too short to be easily detected by the motion control hardware so an extra “box” is needed to lengthen the camera pulses to be able to synchronize to the camera – that is assuming one needs to. Many shots with high speed cameras are often just single passes so they would not require synching.

Please contact MRMC to get the most up to date interfacing information about your camera.

Arri 435 Can synchronize at any constant speed
Arri 435 Advanced/Extreme Can synchronise at any speed and can do Vari-speed if camera has moco option hardware
Arri Alexa Can synchronize at any speed
Arri Alexa M Can synchronize at any speed
Arri 235, 535, any film cameras Can Synchronize at any speed
Moviecam Compact Can synchronize at any speed
Red One Can synchronize at HD speeds (24,25,30) but requires genlock
Red Epic (firmware still under development) Can synchronize at any speed and could be used for vari-speed.
Panavision Genesis Can synchronize at any speed
Panavision Millenium, XL, any film cameras Can synchronize at any speed
DSLR No synchronization available
Phantom Can synchronize at any speed up to about 300FPS (not limited by camera) but requires extra hardware
Photosonics film cameras Can synchronize at any speed up to about 300FPS (not limited by camera)
Sony video cameras Can synchronize at video speeds
Panasonic video cameras Can synchronize at video speeds
Thomson/Grass Valley Viper Can synchronize at video speeds
Weisscam Can synchronize at any speed
SI-2K Can synchronize at any speed

CONTACT

Head Office (UK)

Telephone

+44 (0)1342 838000

Fax

+44 (0)1342 838001

Rental

+44 (0)7757 330 545

Email

info@mrmoco.com

Address

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Eastbourne Road
Blindley Heath
Surrey
RH7 6JP
United Kingdom

VAT: GB 200-0201-71

Head Office (USA)

Telephone

805-418-0463

Email

usinfo@mrmoco.com

Contact

Dan Brown

Cincinnati, Ohio