In our age of instant nostalgia, a big question for any documentarian or oral historian is how soon to take a look back at a beloved property.

Do it too soon and you’ll have more participants available, but with so little distance or reflection that you might as well be making a promotional EPK.

The Bottom Line A slight but sincere 50th anniversary gift to fans.

Venue: SXSW Film Festival (Documentary Spotlight)

Director: Linus O'Brien

1 hour 29 minutes

Do it too late and none of your first-hand sources will be available, so you might as well be making a shoebox diorama.

Watching Linus O’Brien’s, a new documentary launching out of SXSW, my most frequently thought was that — actual quality of the film notwithstanding — it’s an absolute blessing to be getting this examination of the Rocky Horror phenomenon at this particular moment in time.

Released tied to the 50th anniversary of the film, Strange Journey benefits to no small degree from the presence of O’Brien, son of The Rocky Horror Show creator Richard O’Brien — which means access to archives and memories and presumably easier facilitation of conversations with an astonishing assortment of people associated with the property at every level.