Leprecon LP-3000 Series - Manual (Page 87)

Moving Light Controller—Overview Chapter Seven 83
LP-3000 Users Manual
Effects: Prisms and Frost (Beam Property)
The number of elements that can be introduced into the optic path is limited only by
the imagination of instrument designers and the budgets of the users. Besides the
standards of gobo and color, several popular instruments incorporate another
general-purpose wheel for effects. These can include prisms to split the beam, color
correction filters and diffusion media or “frost”. The exact features that are loaded in
an effects wheel can vary widely.
Zoom and Focus (Beam Property)
Because Moving Lights are used for their static properties as well as their ability to
move, manufacturers have added motor controls to the optics. The results are the
ability to control the “sharpness” or definition of the beam edge (focus) and the size
of the projected beam (zoom). Controlling the beam size with the iris maintains the
intensity as the area of coverage changes. Zooming the fixture concentrates the
light into a larger or smaller area with a corresponding change in illumination.
Dimmer (Intensity Property)
The high-performance Moving Lights of today usually utilize discharge lamps as a
light source. These arc lamps are compact, efficient and have a high color
temperature. On the down side, they require a large and heavy ballast and cannot
be dimmed electrically. As a result, the dimming system usually consists of a
mechanical element such as a disk with progressively narrower slots.
Mirror (Focus Property)
The positioning of the mirror is responsible for the “focus” or position of the beam.
Generally, stepper motors are used to set the mirror position, with an XY axis for
pan and tilt. Some instruments use a single 8-bit value for mirror position; other
instruments use a 16-bit value. This information is significant only for ensuring that
the LP-3000 set-up for an instrument is correct.
Because of the limitations in the pan and tilt mechanisms, the area that a moving
mirror can light is restricted.
Instruments such as the Vari*lite and Studio color, on the other hand, are moving
head or true moving lights. These instruments are less restricted in their range of
movement but use all of the features of the LP-3000 Moving Light Controller
software as a moving mirror instrument would.
No Change
On the LP-3000, there is an important feature known as No Change. This is
referred to as Transparency in some moving light controllers.
Moving light programming requires that each light in a cue be assigned values for
the four properties described above—beam, color, focus and intensity.
In some cases, you may want the light to have the same color, for example, as the
cue that precedes it. If you know that the sequence of cues will always be CUE_001
to CUE_002, then it is safe to hardcode the colors for the two cues so that they will
be identical.