In SD, there is only 4X3. To have 16X9, you need to either have it squeezed anamorphically (which you have) or letterboxed. Since you already have an anamorphic image, you could output to tape that way and the end user can letterbox it. If you go to DVD, you can do the same thing adding a 16X9 anamorrphic flag which tells the DVD player to either letterbox it, or cut the center out depending upon viewer preference.
So the question is, why do you want to letterbox it? You will lower the quality by reducing vertical resolution. If that is what you want, then you can simply add the 16X9 letterbox effect which you will find under the “reformat” heading in the effects menu. If you happen to be on an ancient Avid that doesn’t have this, just drop a resize on there and set the vertical to 75.
Terence Curren
http://www.alphadogs.tv
http://www.digitalservicestation.com
Burbank,Ca