I'm a little confused about a couple of things, both
spacing and the term "centers". When these books that I read talk about
spacing, such as on "1'6" on center" what exactly are they talking about? And how does this refer to creation of light plots?
Somebody help me, I am so confused!
Thanks ~Paul
Lighting units hung on a lighting position, need to be mounted in such a way so the
instrument can focus to the desired location. This means the
unit must have a certain amount of space around it to focus.
Typically, and on a horizontal lighting position, such as a
truss or
electric pipe, an
ellipsoidal might need about 1'-6" of space between it and any adjacent ellipsoidals, as measured from
c-clamp to
c-clamp, or center of
unit to center of
unit (in the case of moving lights).
Different units need more or less space, depending on the intended focus and or
unit size. As example:
- Ellipsoidals (Source 4) all focusing in the same upstage or
downstage direction can often be hung 1'3" center to center.
- Units whose beams cross shoot across the
stage at 45 degree angles to each other, might need 1'-6"
- Ellipsoidals focusing as a cross
stage shot from the end of the
truss or
electric, might need 2' center to center.
Zoom ellipsoidals such as an
Altman 15-35 Shakespeare
zoom, might need more room.
- PAR64's on trusses are often pre-rigged on 6 lamp bars that have 1'3"
spacing, center to center, as they are generally all focusing in the same general direction.
- 5kw fresnels, or other similar beasts, as used by a film/TV shoot or on an Opera, would need
spacing of 3ft., or whatever.
- Moving (head) lights are very particular, and often need 2'9"
spacing in order for the head to have free range of focus.
The
lighting designer needs to know about
instrument spacing issues and will draft the lighting
plot with
spacing indicated to allow the instruments to focus to the desired location, thus the
light plot will have the lighting symbols drawn and spaced to scale to eliminate
spacing issues. One thing you might see on a
plot, is a note adjacent to the instruments on a position for the first
instrument to be 1'6"
stage left of
center line, and a second note for all other instruments on that position to repeat that
spacing, as example. You then might see a note that say's "reverse and repeat", meaning everything on
stage right is a mirror of
stage left.
Which reminds me of an LD who used to do touring
advance light plots and who would repeatedly specify 40 - 8" fresnels to be hung on a 50ft. pipe. NOT.
Steve B.