well, it depends on what you are trying to do with the final movie.
You said your movie file is about 450 megabytes in size. Assuming is on DV format, then the video last a little over 2 minutes.
If you are thinking in sending the file on a CD-ROM for PCs, then you are much better of using DivX or better yet, XviD compression. That way you can keep the 720x480 pixels resolution (NTSC) and full framerate in excellent quality using less than 10 megabytes (you will need the freeware application called virtualdub to process the video file).
You will need however a decent machine (good processor) to playback the file.
You can also try MPEG-1 using the free MPEG-1 encoder know as TMPGEnc (excellent quality). This encoder also features a very good MPEG-2 encoder, but because of licence issues, the feature is commercial and only available as a 30 day try-before-you-buy. However the MPEG-1 encoding never expires.
Even for a CD-ROM you can try the new WM9 encoder from microsoft (WMV format), that way and you could also prepare the file for internet streaming.
Another excellent format for low bitrate and ready for internet streaming is the Real video format.
I know that Real Player is pretty much hated by many, due to his insistence in taking over every single media file it finds in the computer where it's installed, but the image quality is extremely good for the low bitrate (and low filesize).
Real Networks recently offers a new encoder called 'Helix Producer Basic' (free), so you can try and see the quality/filesize it gives you.
I wrote an article to properly install/configure Real Player One, to make it behave like what it is: a simple media player, restricting the program from taking control over your system.
The article is here:
http://videoproduccion.org/realplayer/
The downside for you (maybe) is that the article is in spanish, but you can follow all the screenshoots and figure it out by yourself.
good day.