Camera Interfacing

Interfacing Information

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, Vision Research, Nikon, Sony, Panasonic, etc. 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.

Synchronizing and “You can fix it in Post”

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), 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. 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.

Speeds 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. Such facilities are rare as the fashion of needing to do vari speed has passed, though it is still available in MRMC Software.

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. Earlier cameras, like the Arri 435 Advanced/Extreme film camera would allow the motion control software full control of the shutter and shutter angle so that one could achieve excellent vari-speed moves, but only on some versions of RED cameras can this be done today. Please contact MRMC to get the most up to date interfacing information about your camera. Most modern cameras require a correct connection of some kind to be provided to enable accurate synchronisation and this may need to be pre-ordered for some less well known cameras.

Specifications

  • Hardware Synchronisation Information
    • Arri Alexa Series
      Can synchronize at any speed
    • Arri Alexa M
      Can synchronize at any speed
    • Arri Alexa Mini
      Can synchronize at any speed
    • Red One
      Can synchronize at HD speeds (24,25,30) but requires genlock
    • Red Epic/Dragon/Weapon
      Can synchronize at any speed and could be used for vari-speed.
    • Panavision Genesis
      Can synchronize at any speed
    • Panavision Genesis
      Can synchronize at any speed
    • Most DSLR
      No synchronisation available from the camera, but can be used for stop motion.
    • Phantom Gold, Flex,4K,Veo, etc
      Can synchronize at any speed up to about 800FPS (not limited by camera)
    • Sony video cameras
      Some can synchronize at video speeds if the Video signal is used.
    • Panasonic video cameras
      Can synchronize at video speeds
    • Grass Valley
      Can synchronize at video speeds
    • SI-2K
      Can synchronize at any speed