The thought of making a film out of this enormous novel, long on talk, short on much action, seems daunting, but Hans Geissendörfer's film does a creditable job, with some allowances for the excesses of late 70's film making (this film dates to 1982, but it really harks back to the 70's in artsy style, much theatrical staging of scenes, an interpretation that is faithful to the book in meaning but not in style, I think.)
The novel, which deals with the seven year sabbatical of a young engineer at a tuberculosis sanatorium right on the cusp of World War 1, is one more in the long line of novels that discuss the huge change in Europe that occurred after this war. Old Europe, and its descent into decadent lifestyle is depicted in the hermetic environment of an indulgent health resort in the Swiss Alps.
The film does a good job of depicting the social decadence, and the conversations between Castorp, his humanist mentor Settembrini, the Jesuit Naphta and the dionysian Peeperkorn are fairly well handled and Rod Steiger (dubbed into German) is superb as the off-the-rails alcoholic Peeperkorn. The casting of many of the main characters is uncannily correct--Marusja, Joachim, Frau Englehardt and even the dwarf Emerentia. The casting of Castorp and Clawdia Chauchat, however, are not as pleasing; Chauchat is too French and seductive, Castorp too young and callow. Settembrini is too much "Groucho Marx" and not enough the urbane Italian humanist. Charles Aznavour is amazing as Naptha.
Many scenes have been deleted from this DVD, so I actually recommend you purchase the set of three Mann films, The Thomas Mann Collection which has the whole series of this film plus a very long miniseries of Buddenbrooks, the novel Mann wrote in his 20's, which is an incredibly good production of his debut novel.