For a project I would like to create pictures like the enclosed (done with a light torch) but "animated". So what can be the best workflow? I'm planning to film with NR1 on at 50i, then do an overcrank, so I have a slow motion at half speed - then maybe slow it down once more. What do you think, what can I do, so the light at the start remain as long as possible?

If I'm reading the image correctly, then all you need is a slow shutter speed.

Maybe I was indistinct! I don't need to do it in still (I have done the enclosed picture) - i want to have it moving (or animated). I need the shot to be about 10 seconds in the end. If possible I want to have "line of light", tracking the moving point (does it make any sense? sorry for my english).

If you film a moving light in camera, then in after effects, track the object and attach the Vegas effects with a long tail. Pretty sure it would give you a moving version of you still image. If you need more than one moving light, shoot seperate lights, apply the effect and then composite them together in after effects.

Maybe I was indistinct! I don't need to do it in still (I have done the enclosed picture) - i want to have it moving (or animated).Yes, and a slow shutter speed will get the effect you want on video too. I just tried it on my XL2 at 1/8 shutter to prove (to myself, at least) that I'm not crazy. :) You seem to be saying that a slow shutter speed would work for stills but not for video. Why would you think that would be the case?

On second thought though, you're right about slow motion, because you'll be able to get a better look at the light trails that way.

You're right about 50i, too... 25f wouldn't be smooth enough to get the effect.

I will try the slow shutter. Thanks for your input guys! /J