You're going about it the wrong way. Playback rate is really to either speed up or slow down play back, not actually change the length of the rendered video.

To change the length (how long a section of video plays) either apply a event velocity envelope (insert/video envelope) or/and drag the right edge of an event while holding down the Ctrl key and you'll see a zig zag line. Drag left (decrease size of event to speed up, drag right to increase size of event and get slow motion. Then don't forgot to resample the event so it plays smooth. When you select resample you force Vegas to interpolate the frames in the stretched event resulting in smooth playback. You won't see how smooth until you render.

I had one second I needed to stretch to 4 weconds.

I inserted a velocity envelope and slowed it down.

Then I rendered it to a new track and had it resample as mentioned in previous posts.

The result was a perfect 4 secind slow motion clip - absolutely flawless.

Thanks everyone for the very informative response. I did check the Resample box and it looks so much better!

Regarding how I am approaching slowing down the video, I think changing the playback option is doing the same thing as the velocity envelope in what I need to have accomplish. I am not looking to expand the length of the video when I slow it down since I only have small segments in the timeline to fill in. So using the playback option ends up truncating the beginning/end of the video segment, and that is fine for this project. But thanks for the tip on using the velocity envelope since I'm certain I will need to use it in future projects when I need the entire video in my project.

Hi DougDVD,

Additional tip: Playback rate and VE can be compounded:

4X playback rate can be further accellerated by 3X VE to achieve 12X... :)


HTH, MPH

Tips:
http://www.martyhedler.com/homepage/Vegas_Tutorials.html