Now turned 90, the extraordinary Portuguese auteur Manoel de Oliveira appears to live in a parallel universe where old age is synonymous with youth, inspiration and energy. His first full-length feature, the neo-realist classic Aniki-Bobo, came an extraordinary 57 years ago, and he was not to make another for 20 years. Only after Salazar's dictatorship was toppled in 1974 did he launch himself wholly into directing full-time, and it was when he reached 80 that hyperactivity set in, with annual releases of films such as No, Or The Vain Glory Of Command, Abraham Valley, The Convent and Journey To The Beginning Of The World. Now, from the heady heights of experience and dignity, the veteran of veterans has sent La Lettre (The Letter) down to us.

Like most Oliveira films, La Lettre stems from a literary work, in this case the 17th century romance The Princess Of Clèves by Madame De La Fayette. Not that this is a reworking, however - Oliveira prefers to act on the understanding gleaned from literature, rather than the telling of it. Sensing the difficulties of re-setting the story in De La Fayette's time, the director has chosen to update the story and has transported the action from the 17th century aristocracy to today's high society.

La Lettre replays the customary Oliveiran quest for greater purity of style, eschewing busy camera movement and special effects, maintaining that the skill of the director is to create the illusion of reality. Objections have been raised that his influence is all-pervading and dissuades the country's young film-makers from experimenting, but Oliveira can hardly be blamed for the overpowering effect of his personal vision. In the meantime, his autobiographical film, The Visit: Memories And Confessions, will remain unseen until after he dies. Let's hope for a long wait… Steve Mackey