The caterpillar lives a simple life crawling around tree branches and munching on leaves. When ready, the caterpillar enters a cocoon and then transforms into a beautiful butterfly. The natural wonder of metamorphosis completely changes the creature from one form to another. Automated lighting programmers are often challenged with equipment changes, and we too must learn to adapt and transform with our surroundings. Although we do not have a cocoon in which to make these changes, we do have specialized software on our consoles to assist with transformations.
Changing Fixture Types
The type of transformation I am referring to is the changing of fixture types once a show is programmed. Often there is a need to replace one fixture type with another, yet still retain all the programmed cue data. There are several reasons for this. First, a touring show may opt to travel only with a console and utilize the fixtures available in each venue. Instead of re-programming the same cues daily, the operator will simply change fixture types and play all the same cues. Second, most touring shows travel with their own fixtures; however they may play some festivals or TV shoots that require a change of fixture types. Another reason for changing fixture types with long-running shows is an update of equipment or change of venue. Furthermore, I have even had to change types during pre-production when the LD opted for a brighter fixture than the one he originally specified. Changing fixture types can also occur when a show was pre-programmed in a visualizer with fixtures in a specific mode and the real rig used a different mode of fixture. In any of these cases, it is important to understand the pros and cons of changing fixtures types as well as the process to do so.
How It Works
As with many automated lighting console features, there are different names and methods for the changing type procedure, so you should refer to the manual for specific details. Some consoles refer to the feature as change type, cloning, adapt fixtures, or other similar terminology. Some consoles use generic fixture libraries that make the changing process very simple. Other consoles simply record DMX data and require intense data copying and verification. In any case, the end result is the change of data from one fixture type to another.
For instance, if I have my show programmed with 12 hard-edge fixtures of Brand X, I can change them to Brand Y, and in theory all my programming will be intact. I will likely have to update my color mixing, gobos, focus/zoom, and positions, as those details are expected to vary from fixture to fixture. This is where the use of palettes (or presets) becomes invaluable. You should always program using palettes, especially when you plan to change type. This speeds up the process of cleaning up the data after a change type, because you can simply update your color, beam, and position palettes to values that work best with the new fixture type.
The Generic Fixture Library
Consoles that utilize a generic fixture library store data based on generic parameters instead of storing DMX values for each parameter of the fixture. For instance, rotating gobo values are always assigned in the same manner, regardless of fixture type ("Rotate Gobo at 42 rpm," for example). Consoles without a generic fixture library will instead assign rotating gobo values based on the method required for each fixture ("Channel 12 at DMX 147," for example). Of course, the console with the generic model does have to convert its generic data into the specific DMX values, but it does this at a low level in the background. Because all data is stored in a generic manner, the console can easily transform its data from one fixture type to another. Usually these consoles have a button that can be pressed to change fixtures from one type to another. At that moment, the user will see the fixtures change from Brand X to Brand Y, and all programming including groups, palettes, cues, etc., will be updated to work with the new type. Basically the programming level data remains the same, while the underlying mapping to DMX values changes. However the programmer does not have to be aware of the console magic, and can simply change type and start playing cues.
The DMX-Based Library
Many consoles utilize a DMX based library system instead of a generic library. This means that data is always programmed and stored as DMX values for fixture parameters. This manner of data storage makes changing types much more complicated and error-prone. Typically these consoles allow the programmer to clone data from one fixture type to another, but remember that only the DMX values are being copied, so this can lead to extreme changes. For instance, one fixture's strobe value may copy into another fixture with very different strobe rates. When working with these types of consoles, it is important to copy the palette (preset) data first, then the cue data. If you copy the cue data first, then you will likely lose palette references within your cues. Furthermore, remember that it can be very time consuming to copy individual cues throughout a show. Try to make use of macros to speed up the process. Some consoles with a basic DMX library may have an automated method to clone data, but the result still needs to be studied, as differences in fixture DMX values are not usually corrected.
Modern Problems
I have used cloning and change type on hundreds of shows, and was recently taken by surprise with some modern technology. I had programmed a concert tour that used some fixtures that have two forms of intensity and color. You know, the ones with the big LED rings on the front. A few months after the tour ended, the band was asked to play a festival show using the festival rig and part of our rig. We decided to clone our LED ringed fixtures into the standard hard-edged fixture on the festival plot. All the changing of data worked like a charm, except for cues where we had utilized output from only the LED ring. Whenever the LED ring was used on its own, the main fixture had its shutter closed. So several songs of the cloned show had the hard-edge fixtures moving with no output! During the pre-production a year and a half before, I did not anticipate having to change type, so the show file was not ideal for this change. In retrospect, I should have created a special palette called "LED on" that closed the shutter and turned on the LED ring. Then, when I changed type, I could have just updated that palette to have the shutter open. Instead, I had to go through the cues to find and update all these LED-only instances.
Embrace Change
It is often said that people fear change. However, you should not fear having to change your fixture types with a programmed show. You should understand the capabilities of your console and program with change in mind. Utilize palettes and document the looks that you create. By doing so, you are creating a cocoon from which you can fly like a butterfly with a new set of fixtures.
