Michael Radford’s sumptuous version of The Merchant of Venice will soon be available on videoDVD. Film Shakespeare is nothing new - his plays were a mainstay of early cinema - and, largely thanks to Zefferelli and Branagh, they have proved to be good box office.

“And yet,” says freelance film writer and trainer Jill Poppy, “lots of English teachers are nervous when it comes to exploiting film versions of Shakespeare.”

“It is such a missed opportunity,” adds Barbara Bleiman, of the English and Media Centre. “When teachers resort to using the movie as some kind of treat after all the ‘hard work’ has been done reading around the class on a play.”

“There’s a danger of introducing screen versions too early,” says QCA head of English Sue Horner. “There is an emphasis at all key stages on students having a sense of the plays in performance, but it’s a shame when we ask them to come up with directorial opinions about a SATs scene and end up with regurgitated Lurhmann or Polanski.”

“The key thing is that students get a sense of different versions of a play,” says Jill Poppy. “This is one of the great things that compelling film Shakespeare on video enables us to provide.”

Also, the texts that have come down to us are highly “unstable” or “provisional”, as York University lecturer Dr Judith Buchanan says in the introduction to her forthcoming book on the subject. Every play, she argues, is “inherently a document of possibilities that can ambush us anew”. Film Shakespeare in the classroom has the potential to bring this home to our students.

What potential ambushes does Radford’s Merchant offer? The opening “contextualising” sequence gives a whistle-stop tour of Venice in 1596, with its regulations governing Jews leaving the ghetto, and a dramatisation of Antonio’s “voiding his rheum” on Shylock when they meet on the Rialto Bridge.

It would be well to juxtapose this with the credit sequence of 1930s footage that sets the scene for the 2004 Trevor Nunn film version of his National Theatre production. Then there is Palladian Bellmont, all fairytale frescoes and light in Radford’s version, providing an intriguing contrast to the somewhat ponderous Venetian interiors in which we encounter Antonio and profligate Bassanio.

Any version of this play must face examination for its take on the anti-Semitism elements. In Radford’s film inspiration for the bond springs from Shylock’s on-screen purchase of goat’s meat and seems as much an act of whimsy as of murderous intent. Alternatively, Radford’s use of Jeremy Irons as Antonio has proved problematic for some, as the actor’s ascetic appearance makes him seem particularly Christ-like his the courtroom ordeal, just as it casts Pacino’s Shylock in a darker light. Again, Nunn’s version of the trial scene would be an intriguing counterpoint given David Bamber’s oily and vindictive portrayal of Antonio. It is telling that in both, there is an explicit attempt to put distance between Shylock’s actions and his fellow Jews, represented by an increasingly dismayed (and in the Nunn explicitly rejecting) Tubal. Radford also adds to the scene’s ambiguities by giving extra emphasis to Shylock’s condemnation of his Christian opponents’ hypocrisies by focusing the camera on a single stoical black slave in their midst.

For Judith Buchanan, a key to both the trial scene and Shylock’s “Hath not a Jew eyes?” speech is the edgy camera-movement, which conveys a sense of the instability underlying both scenes. It is a sophisticated point, underlining another important issue - that to get as much as possible out of film versions of Shakespeare, pupils need to have a good understanding of film grammar - the framing, mise en sc ne, movement and editing that come together to create meaning. And for that to happen, teachers will need to grasp these basics too.