“Ridiculous.” “Defies plausibility.” “Blissfully divorced by logic.”

Then there are the contradictory comparisons.

“So preposterous, yet so believeable.”

“So suggestive, yet so innocent.”

“Dark and violent . . but tasteful.”

You’ll hear those words used in surprisingly positive ways to describe Alfred Hitchcock’s brilliant 1959 thriller “North by Northwest” on a new DVD celebrating the film’s 50th anniversary ($24.98 DVD, $34.99 Blu-ray; Warner Home Video; available now).

The one word you’ll hear most of all: masterpiece.

The film — about a suave businessman who is thrust into a world of danger and intrigue — was a collection of the themes and motifs used by Hitchcock: mistaken identity (Cary Grant), the suave villain (James Mason), the powerful mother figure (Jesse Royce Landis), the cool blonde (Eva Marie Saint). It’s all eloquently explained in two new documentaries, “The Master’s Touch: Hitchcock’s Signature Style” and “North by Northwest: One for the Ages.”

Filmmakers William Friedkin, Curtis Hanson, Guillermo del Toro (could I just hang out with this guy sometime?), Francis Lawrence and screenwriter Christopher McQuarrie have much to say about Hitchcock, and they say it well.

Del Toro, the imaginative mind behind such films as “Pan’s Labyrinth,” poetically describes two of Hitch’s most famous scenes — Grant running from a crop-dusting plane in a cornfield and the chase across Mount Rushmore — as “symphonies of pure cinema.”

The “Signature Style” documentary cleverly takes vintage footage of Hitch discussing his movies — interviews that have appeared on previous documentaries — and freshens them up with comments from the modern directors, as well as showing examples from his films to illustrate points such as Hitchcock’s visual storytelling, point-of-view editing, his use of suspense and the way he often manipulated audiences to root for the villain.

The DVD also has a screenwriter commentary, music-only track, the 2003 Turner Classic Movies documentary, “Cary Grant: A Class Apart” and a making-of hosted by Saint.

Also available this week for Hitchcock fans is “TCM Greatest Classic Films Collection: Hitchcock Thrillers” ($27.92), a nice two-disc set with “I Confess,” “Strangers on a Train,” “Suspicion” and “The Wrong Man.”

Coming Tuesday

“Dawson’s Creek: The Complete Series” (Sony), “Doomsday 2012” (A&E), “Enlighten Up” (Docuramafilms), “Natalee Holloway” (Sony), “Rethink Afghanistan” (Disinformation Company), “Move On: The Movie” (Disinformation Company), “Spread” (Anchor Bay), “The Ugly Truth” (Sony), “Up” (Disney/ Pixar)