Michele Soavi, writer and director, presents his view on Dario Argento. There is no better person to present a documentary on Argento, as Soavi has studied under the man (as well as other great Italian legends), and through his tutelage went on to be the greatest Italian horror director of his time... to see this early attempt at directing is instructive of both Argento and Soavi.
The documentary was released in 1985, so it focuses on behind the scenes on "Phenomena" and the process by which a hornet was put to sleep with ether, surgically modified and remote controlled, as well as other camera tricks and special effect work. It's an interesting take on how effects were much different 25 years ago.
Another reviewer opined that parts of this would work better as featurettes on the other DVDs, and I absolutely agree... though, of course, in 1985 movies did not have special features. With the rights to many films being owned by Anchor Bay and this one by Synapse, I'm unclear how that would work.
The best bits are by far the interview segments with Argento, where we learn that he thinks his murder scenes are "beautiful", how murder is "erotic" and "sensual", and how he worries that he does not have the skill to pull off his ideas. It's a very sympathetic look, but also a frank one. He speaks his mind, as unpopular as his views might be.
If you do not know who Argento is, this may not be the best introduction. But if you've seen a few of his films and want to see more, this should put you in the mindset to continue your journey. Experienced fans might not find much new here, especially after all these years, but I have seen the bulk of his work and still found it insightful.