4-axis motion control
The spectrum st4 is an integrated 4-axis controller.
This enables complex moves with simple and fast setups. Is 4-axis better than 3 axis? We think so, especially since setting up a Pan/Tilt/Slide and Focus, or a Pan/Tilt/Focus/Zoom is now as easy or easier than setting up less dynamic footage with other controllers.
Pan/Tilt/Focus/Zoom tests– Using 3 GoTo Frames with coordinated motion ramping. Setup and run time 2 minutes. Gear Nikon D810 with 14-24 F2.8. eMotimo spectrum, and 2 Fz motors.
Pan/Tilt/Focus/Zoom in the field – This is the most mobile 4-axis motion control in existence. Using GoTo Frames with coordinated motion ramping. Setup and run time was 10 minutes with 3 users playing. Gear Nikon D810 with 14-24 F2.8. Lightweight PTZF kit of spectrum and 2 Fz motors is 7lbs on a 2.2 lbs mini tripod/ballhead. Camera /Lens Filter 5.5 lbs. Battery. 1.2 lbs.
Slide/Zoom for Hitchcock. We used a small amount of pan and tilt for fast framing here too, but it is subtle. Kit consisted of the Nikon D810 with 14-24 F2.8 on the shark slider with a single Fz motor. This is basically our 4 axis bundle!
Brian’s Tech Corner –
How do we control so many motors smoothly? Most other motion controller rely on a single main processor to generate and analyze control signals. As you add more motors the processor has greater and greater demands placed on it. If your micro-controller is low powered, or low data width, it will bog down with the load. To accommodate you start lowing the speed of your feedback loop, or make your motor moves more course. For timelapse, this isn’t much of an issue because you only care about your position at a particular frame. For video you care a lot! Your smoothness or your trajectory goes out the window and looks like junk as you speed up or try to multitask (read a remote, update a screen, communicate with other devices). This is main reason why eMotimo moved away from 8 bit hardware and slow clock speeds and up to 32 bit ARM micro-controllers running really, really fast.
In addition to a faster and more efficient main processor we added four motion co-processing chips for each axis! Results are we have a processor that is currently using a small percentage of its resources to run even the most complex moves. With the extra resources, we can start doing really fun things like mixed mode playback where some axis are controlled by the spectrum and some are controlled live by the user. You won’t see anyone else doing this in the near future with their current hardware!