An increasingly prolific genre of the home-DVD market are the independent "review and criticism" releases, which focus mostly on classic-rock artists and are manna for hardcore fans. And no performer has generated more titles than Bob Dylan.

This release focuses on dissecting Dylan's least-covered but still very controversial era: the trilogy of tubthumping evangelical releases reflecting Dylan's conversion to Christianity (Slow Train Coming, Saved, Shot of Love), through efforts of a hodgepodge quality (Infidels, Knocked Out Loaded) and his arguable career nadir (Dylan and the Dead, Down in the Groove) to the simple but wonderful Traveling Wilburys and the welcome (if short-lived) "comeback" of Oh Mercy.

The "review and criticism" DVD template is followed by recruiting talking heads to tell the story. They range from music journalists (some with a Dylan specialty) like Clinton Heylin, Anthony Decurtis, and Nigel Williamson, to players, producers, and engineers on the sessions, with a unifying narrative voiceover. In this case, all expound well in Dylan's records, shows, and (purported) state of mind at the time. Coverage of The Gospel Trilogy and tours are the DVD's best.

Of course, Both Ends of the Rainbow suffers from the usual malady of R&C DVDs - and that's the lack of actual music and performance footage from the artist in the title. Whether it's a licensing cost or permission issue, there's little actual Bob Dylan singing or playing here - and the footage that is included looks like third-generation VHS tape copy.

The talking heads do discuss in depth two of the more interesting aspects of Dylan's studio proclivities during this period: His overuse of female gospel backing choirs (much to the detriment of "Brownsville Girl"), and sticking to his preferred no-frills method of studio work. Dylan would show up, briefly run through a song for whatever backing band was cobbled together for the session and record. Much of the time, it was that first or second take (if indeed there was a third) that was used on the record.

Shot of Love producer Chuck Plotkin tells the story about recording one of Dylan's best latter works, "Every Grain of Sand" - which might not have happened had Plotkin not rushed over and held a hand microphone to Dylan's mouth as he abruptly premiered the song on piano. Bob works fast.

Both Ends of the Rainbow is an illuminating look at a lesser-known - but no less important - phase of Dylan's still-evolving career. But it's for hardcore fans only.

Chrome Dreams Media, 127 minutes, $19.95.