thanks all for your help - i thinked i cracked my immediate problem by just scaling up the light then everything else seemed to fall into place - although i'm not 100% sure exactly how i got it to work, as i was trying lots of different things

if you guys wanna see the result, go here:
https://www.twobrowngirls.com/tc/las_...ype%20test.mov

it's an mpeg4 quicktime movie and plays on mac and pc

just one more thing - i bumped up the contrast in after effects as the original output was a bit flat - is there a way of acheiving this in maya - i've fiddled with various parameters but could not get what i wanted, especially to make the light streaks more obvious

cheers,
tony