Assuming that you have software that supports multiple overlay layers, then you could create the trail effect by duplicating the video on subsequent layers. On each of the subsequent layers you would offset from the preceding layer by a few frames and increase the opacity. You could also offset the position of subsequent layers by a few pixels to further enhance the effect.
Hope that makes sense.
COMPAQ something or other with 500Gb Boot Disk, 1Tb external Firewire Disk, 4Gb Memory and a super duper sound card, 19" TFT Monitor etc etc etc
Sony TRV33e : Sony TRV310e : Canon XM2
Sony Vegas Studio editions to v11
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