HD Videos

I film all my videos with my HTC Desire HD, the videos are of HD quality. When i use Sony Vegas i save as an .mp4 file however the video result is not in HD quality and is rather poor compared to the videos that i produced from the same device when use to use CorelVideoStudio.

So the quesiton i ask is what format do i save the video as to keep the HD quality..

Thank You

Vegas Pro and the mp4 is MainConcept AVC/AAC (.mp4)

Altho hold just had a nosey and i was clicking Render As.. but now thinking do i click on Capture Video.

Thank you for the advice, i shall do that now