with good results
There's the catch. I personally wouldn't use SD clips in an HD project, just because it could never match the quality of the real HD footage. But a popular method for such upscaling is Instant HD from Red Giant.
Thanks, Jim. I'll give Instant HD a look.These are artist interview clips that are unique. If they end up soft I may have to use some effects to give them an "archival" look within the new production.
If you wait until october for the new features to be released especially for AE: upscaling SD to HD and beyond.