HTP or Highest Takes Precedence is a term used to define the convention of channel level control, where the highest level of a channel is output from the Lighting Desk or lighting software interface, if there is more than one channel level control option.

This control convention was developed from what we know of as a "preset" Lighting Desks.

The channel levels are combined from all of the different channel sources, which could be a single set of channel faders, or two sets of channel faders or "presets", or a combination of preset and scene faders. As an example, if preset A channel 1 is set to 50 percent and the preset master is set to 100 percent, then the channel level output will be 50 percent. If we then set the preset B channel 1 fader to 70 percent (while leaving the preset A channel fader set to 50 percent) we will not see any change in channel 1 output level until the preset B channel 1 fader gets to 51 percent, then the channel 1 output level will increase as we increase the preset B channel 1 fader to our desired 70 percent.

The preset A channel 1 fader will now have no affect on the channel 1 output level as it is not the Highest source of output level for that channel. If we change the preset A channel 1 output fader to zero, it will not affect the channel 1 output level as the preset B channel 1 fader is set to the Highest level so it has precedence for determining the channel output level.

Each set of preset or scene faders usually has a preset master or scene master or submaster which determines the channel outputs by scaling them and there may be a Grand Master as well which controls all channel levels. When these masters are changed, they affect the output level settings of all preset channels or scene masters they control. As an example, if we set all of the preset A channel faders to 100 percent and start with the preset master at zero, the the preset channel levels will all be zero. If we move the preset master to 40 percent, then all of the preset channel levels will change at the same time (and rate) to 40 percent.

This is a desirable feature for conventional theatre lights as we have overall control of all channels and apart from the colour temperature of a luminaire changing as we dim it, there is no undesirable outcome from this action. However if we are controlling a function or attribute of a moving light or colour scroller which has been set to a desired value, say tilt at 60 degree and pan at 30 degree or a desired colour, by using our channel controls, when we change our preset master or scene master or Grand Master, we change the levels of all channel outputs, so change the attributes of the moving light or colour scroller and they will change to something we do not want it to change to.

There may be ways to overcome this such as using a scene or preset to control the moving light attributes or avoid using the Grand Master, however it is easier to use a lighting desk or controller that uses the Latest Takes Precedence method of control.

With digital lighting control, which is what most modern Lighting Desks use, the highest value for a channel is determined by the processor as part of its program functions. This allows the channel to be controlled from say a submaster a cue and the command line. The channel's value will be set to the highest of the three. This is the most suitable control method for intensity channels. Latest Takes Precedence is similar, however it takes the latest value to be changed, which is more suitable for non intensity channels such as colour or gobo wheels on a Moving Light.

A DMX merge can also carry out the function of Highest Takes Precedence.

See Also

• Latest Takes Precedence