The first essential is to right-click on the clip, then choose Properties and check Resample. This will create interpolated frames to fill in those that are missing. I've heard experts on this forum talk about Vegas's slo-mo as being some of the best they have seen -- but you must click resample! Others can fill you in on other secrets, but I think that's No. 1.
You might also check Reduce Interlace Flicker. This seems to help when slowing down really fast scenes to real slo mo. And it helps smooth out image changes when the scene was shot by an unsteady cameraman.
Steve
shooting light:
...maybe, and I insist on MAYBE you could get some improvement using "CamStudio" and finding your own receipe with the video prefs in this program... it doesn't take that much space and it's a very usefull programm for some of us to acheive some tricks...
www.camstudio.com
You can also add just a dab of **motion blur** in the right area...
...OR double the track, put it one track down the "master" one, offset it by a few frames (2-8 frames) then play with the levels for each track, thus creating a "false resampling". At the end of the sequence, you put a fade out on the second track before the "master" one is ended so you have a clean start and a clean ending.
Image will be doubled but I guess you should work something out this way too.