Ghost is designed for accurate timing. It can only be used for a total length of one minute. If you need longer, make cuts.
The Start Offset is in Seconds of Time (regardless of frame rate). The 0.5 offset is good for most applications, but this can be changed to suit. The Fade Start Time should match the Start Offset, but you can use the still to effect.
The Slow parameter allows you to slow down the playback timing of the ghosted video. This can be used by itself or in conjunction with Start Offset for a customized appearance.
Opacity is the “density” of the ghost image. If you use more than one of these effects on a clip, it is a very interesting variation to have the last Ghost added by at 100% Opacity when used with green screened footage (see the video).
The rest is just about fading the effect in or out.
Fade In, Fade Out, Fade Start Time, and Fade End Time are in Seconds of Time (regardless of frame rate).
The important consideration here is the Fade Out Time needs to be less than or equal to the length of the clip Ghost is applied to. It is set to 60 seconds by default. If you’re clip is 5:24 long, the easiest thing to do is set the Fade Out Time to 5.0, or do the math (which comes to 5.8 in this example.)