Continuous Motion; Shoot-Move-Shoot Motion; Lead-In And Out - Dynamic Perception MX3 User Manual

7.3. Continuous Motion

Continuous Motion is the most common motion mode for daylight videos. In continuous motion,
short pulses of electricity are sent to the motors several thousand times per second. The faster
the speed requested, the more often these pulses are sent. The one drawback for this method
is that motors do not have an effective speed range from 0% to 100% of their speed, but instead
have an effective speed range, typically, from 30% to 100%. This is because the motors must
be energized long enough to actually start the load moving, and when power is applied only for
very brief periods of time the motor does not build up enough torque to start the load moving.
The MX3 has a specially-crafted driving method which can greatly increase the low range of any
given motor, but it is still important to choose the correct motor for the correct application. For
very low, continuous speeds, motors with the lowest available RPM should be chosen.
In continuous motion, the speed display is the distance to travel per minute.

7.4. Shoot-Move-Shoot Motion

For SMS motion, between each exposure the motor is moved a short distance. In this case, the
motor is moved at full speed for a brief period of time. This allows the MX3 to produce very short
movements over long periods of time, by breaking the move up into very small moves that are
executed once per interval. For example, you may find in continuous motion you are limited to
0.1" of travel per minute, however, in SMS you could dial in one 0.1" move every 30 minutes -
resulting in a speed that is 30x slower than continuous.
SMS motion also allows for the use of very long lenses, critical focus, and extreme exposure
lengths by eliminating any movement during the exposure.
In SMS motion, the speed display is the distance to at each interval.

7.5. Lead-In and Out

Lead-in and out specifies a number of frames (exposures) that must be shot before a motor will
start moving. Each motor can have its own lead setting, allowing for more control over your film.
To set the lead-in/out frames, go to the correct Motor Control screen for the chosen axis, and
Page 26 of 45
Copyright © 2013 Dynamic Perception LLC
dynamicperception.com
All Contents licensed under the Creative Commons Attribution Share-Alike 3.0 License