September Issue - PLSN.com

TECHNOPOLIS
MOVING
LIGHT
MENU
A B
stepper motor
By JohnKaluta
I
have a confession to make: I snuck into
the TV studio at school the other day and
stole their lighting controller. It was summer,
so they weren’t actually using it, and I
wanted to fiddle with a new moving light
I received that morning. I needed a nice,
small DMX512 controller and they had one.
I carried the thing down to our theatre, set
everything up in our orchestra pit and began
to put my new light through its paces.
In particular, I wanted to fiddle with the
menu controls. All of the latest intelligent
lighting fixtures have an incredible (let’s
be honest, overwhelming) number of menu
options and settings. You can change the
menu settings without a controller (right
there at the light) but having a controller
next to the thing makes it easier to see
the results. It was also kind of fun to play
with the sliders and watch my new toy spin
around and around right in front of my eyes
. . . but, hey, I’m easily impressed.
Appetizers
I suppose the most important menu
setting would be the DMX address itself.
How many of us have struggled with an erratic
unit, only to find that the address was
set incorrectly? This happens a lot when we
have to take a unit out of service and hook
up a new one. Somewhere during the swap
the correct DMX address gets forgotten.
Push a few buttons, problem solved. (At our
school installation we have a piece of white
gaff stuck on every DMX connector with
the “proper” DMX address written right on
it. Yes, I realize that this is cheating.)
For today’s experiment I went way out
on a limb and assigned my new light the
DMX address of, um… one. Actually “001,”
which is also the default address for most
units (and the address that corresponds
with the “slave” setting when lights are
strung together without a controller nearby).
Of course, this actually assigned my first
sixteen addresses, since my new light has
sixteen controllable features. And, to get
back on-topic, almost all of these features
can be changed in the menu.
Salads (The menu is trying to
tell you something…)
When I turned on the controller the
menu on my light very kindly stopped blinking
at me, an indication that the DMX was
working. I also got a somewhat cryptic indication
that the lamp was on and functioning
correctly. Knowing these subtle indications
(in this case, a lit decimal point) can save a
lot of hunting around when things aren’t
right. Plinking through the menu I found
the “Test” function, and the “Lamp On/Off”,
both very useful, as you might imagine.
Other standard menu options were “Reset,”
“Time,” and “Display.” Reset is sort of like a
warm re-boot on a computer, re-aligning all
the filters and gobos, which sometimes get
out of adjustment. Time tells you how old
the lamp is so you can replace it before it
blows, Display allows you to turn the menu
display off so it won’t annoy your audience.
Some of the other menu items are a little
more esoteric. Suppose we have a dozen
similar units, half of which are hanging upside
down above the talent. Change the
“Rpan” and “Rtlt” in the menu and all of the
units will track together left-to-right and upand-down.
Rpan also comes in handy when
units face each other, you can set one side to
mirror the other, greatly simplifying the cues.
There’s also a “Disp/Flip” setting so that the
now upside-down menus can be set to read
correctly. Why bother? Any trick to save a little
trouble further down the line is worth it.
All we have to do is step through the
menu until the menu option we want appears
on the display, then activate or deactivate
the setting. Of course the display
characters and features are different for different
manufacturers, but if you can figure
7.5 per step
out text messages (U KN 2 THT, RT?) you can
figure out the menu abbreviations.
You want that to go?
Imagine discovering an incorrect DMX
assignment on a somewhat inaccessible
unit. Never happens in real life, but hey, let’s
pretend. Some newer intelligent lights allow
you to reassign the DMX address from
the board. [Now that the Remote Device
Management or RDM protocol allowing bidirectional
communication has been published
we will start to see a lot more fixtures
with this capability. – ed.] It’s a little tricky
until you’ve done it a few times; I freely
admit I have to step through it with the
manual open right next to me. Setting several
channel controllers just so sends a DMX
assignment change to the distant unit. Not
something I like to do often, but it saves a
lot of ladder work. It’s theoretically possible
to call this function up by accident, which
is why you can turn the option off at the
menu if you wish.
Supersize it?
The unit I was experimenting with also
had an option (menu accessible) to change
the pan limits from 630°, which is more
than some other units, to 540°, which is a
little more standard. Imagine the difficulty
of interpolating the differing settings when
mixing these lights with older stock and
you will appreciate the menu tweak. Most
manufacturers have a special feature or
two like this that needs menu access; look
for them in the online manuals. This is probably
not the right time to tease the manufacturers
about the poorly written manuals
(Hey… I know a good writer), but, yes, the
manuals could be a little more helpful. As
I’ve said before, stare at the manual (and
the menu) long enough and it will eventually
make sense.
I still have to return the lighting controller
to the TV studio, but not before I play with
the rest of the menu options on my light. I’ll
tell you about it next month. As my students
say, “Mad props!” to Eric and Ray over at Elation
Lighting for providing the test unit, a
Design Spot 250.
Ad info: www.plsn.com/rsc
John Kaluta teaches Research & Experimentation
and Robotics at Montgomery Blair
High School in Silver Spring, MD. He is also the
author of The Perfect Stage Crew, The Compleat
Technical Guide for High School, College,
and Community Theatre, available at
the PLSN Bookshelf. And, yes, he returned the
TV studio lighting controller to the TV studio.
He can be reached at jkaluta@plsn.com
38 PLSN SEPTEMBER 2006
www.PLSN.com