As coincidence would have it, "Cymbeline," the latest of the Shakespeare plays to be taped by BBC-TV and Time-Life Television, takes to the air tonight (at 8 on Channel 26), while Arena Stage is tussling in the flesh with the rarely done work. In both cases, it's a long three hours, but if you feel a compunction to round out your knowledge of the Bard with one of his decidedly lesser works, the television version is the better bet.

The play is a me'lange of poisonous potions, separated lovers, long-lost sons, an evil step-queen and a fair amount of gore, which scholars have classified either as tragi-comedy or romance, partially in an attempt to justify the rampant improbabilities of the text. Most of it revolves around the fair Imogen, the virtuous daughter of King Cymbeline, who is put through all manner of perils before she is reunited with her exiled husband Posthumus. The Victorian age found her one of Shakespeare's most estimable heroines, steady in her duty, patient in her suffering. Helen Mirren, a laudable actress who remains delicate and grave in moments that could easily turn purple with passion, helps you understand why.

The production also benefits from a splendid performance by Claire Bloom, whose cool beauty and contained, ladylike manner transform the evil queen into something more than the Disneyesque creature she appears at the Arena. The casting is strong, too, in the case of Paul Jesson, as her foppish son Cloten; Robert Lindsay, as the villainous Jachimo, and Michael Pennington, as the exiled Posthumus, although the actor tends to rant once that beleaguered prince regains Britain's shores.

It is really the camera, however, that makes all the difference, allowing us to eavesdrop on scenes that, of necessity, have to be played with greater force in the theater. The intimacy helps. Director Elijah Moshinsky (whose "Midsummer Night's Dream" was one of the highlights of this series) is thereby able to lower the play's ever-present potential for bombast and rhetoric. The speech that risks sounding hollow in the vastness of the theater gains in credibility when it can be whispered by flickering candlelight or uttered under the cloak of shadow.

The camera also allows him to deal more gracefully than the theater can with the whole matter of Cloten's headless corpse. Mistaking it for the body of her husband, Imogen throws herself upon it in grief and horror -- a scene that is all but unplayable in the theater. Moshinsky cuts away from the bloody corpse almost immediately, concentrating instead on the wan, tormented features of Mirren, an approach that lifts the scene out of the realm of grand guignol.

Since the BBC is taping all of Shakespeare's plays, "Cymbeline" was bound to have its turn, although it would be wrong to say the play is having its day. The best even this intelligently conceived version can do is to make patches of it digestible for our times.