Make sure that either selects the right length to be renderd or have not made a selection if you want to render the entire project. Also keep in mind that Vegas will render until the last marker regardless of the timeline content.

One more possibility. If your source media has a variable frame rate, such as iPhone video, there could be a slight difference in length due Vegas Pro rendering to a constant frame rate.

Thank you for the answers. I am rendering a specific selection. The difference is very small, maybe one second at the end and one at the beginning, maybe less, I have to check this to know exactly. It is very annoying to me because I need perfect sync with a certain length (parts of a musical video that I ll gather them together later).

The source material is made from lots of channels containing different media files: mts and mpeg with fx on different compositing modes. I tried different rendering options, keep getting same extra length. Also at the beginning sometimes I get a very small portion of black screen on the rendered video.

In the end, if I spend some extra time trying to match all these with the original length I can make it to a reasonable degree, but I wanted to know if this is something common for vegas and how can be avoided.

Please state:

1) Project Properties

2) Render Properties

3) Screenshot of your timeline selection

4) Mediainfo report for the rendered file

Have you tried an all-intra render template such as Sony XAVC Intra or something like Video for Windows (AVI) Sony YUV to do your intermediate renders? Avoid codecs with long group of pictures.