Re: beam effect is shaky

this should work (or at least you should get some result, if you have what i think you have)...

you have a solid layer with the beam effect and one end of the beam moves across the screen over one second. choose layer>pre-compose to precomp that layer (choose move all attributes, don't open comp).

now apply the echo effect with similar settings to what i described earlier. you should start to see instances of the beam getting composited with the current beam frame, which resembles motion blur.

as far as interlacing, ae can interlace the render if it is set to tint he render settings, but it will not interlace the previews...

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW