It is often useful to make changes to parameter values discreetly, or without them appearing on stage at all; during a rehearsal or performance for example. To do this, use Hog 4 OS's Fade Changes and Blind functions.
If you select the Fade Changes button in an editor window, any changes you make will appear on stage over the current time settings for the changed parameters. For example, if you have intensity values in the Programmer with a fade time of ten seconds, and you select all of the fixtures and press @
Enter, all of the lights would fade to 0 over 10 seconds. This is useful for making changes on the fly during a performance.
Parameters that don't have timing values in the Programmer will fade in the default time, which you can assign in the Default Timing pane of the User Preferences window:
Setup → Preferences → Default Timing
Press the Fade Changes button again to revert to having parameter values appear in the output instantly.
To view and assign time values for parameters, see Individual Parameter Timings.
You can set a trackball key turn Fade Changes on and off; see Trackball Keys.
Blind mode allows you to continue programming and editing cues, groups, palettes and scenes without changing the onstage parameter values of fixtures. The Blind key is located above the Trackball; when in blind mode, the Blind key will illuminate.
Note that when you turn off blind mode all parameter values that you have changed in the Programmer or editor will instantly appear on stage.
To exit blind mode gracefully, hold down the Pig key while pressing Blind; parameters will fade to their new values in the assigned or default fade time. Alternatively, select Fade Changes in the editor you are using prior to turning blind on or off.
Using Pig + Blind on Hog 4 OS is equivalent to using the Try Cue key on the Wholehog II.