If you love Shakespeare, the various film adaptations of his works hold a continuing fascination (Laurence Fishborne's excellent but cut-down "movie-movie" of this work is well worth seeing for the use of the medium and the performances of the leads), but the occasional filmed productions of his uncut plays are the real stuff.
This Royal Shakespeare Company production was reinvented by Trevor Nunn who chose to set the piece - originally set when Venice was a "front line" state in a world divided between Christian and Moslem superpowers - during the American Civil War. It loses something of the tension of the problem-producing "garrison duty" the troops are left with when they had expected to be in the thick of battle at the start of the play, but balances that practical deficiency with the interest of the unexpected costuming and speculation of the effect of a black general in the great conflict in which free black soldiers (commanded by white officers) were, in fact, considered a "weapon of terror" by the south fighting not just to preserve their right to secede but (so they thought) their right to preserve the slave system.
Of course Shakespeare had already set up the dynamic with a Moorish-born general (North African Moslem born convert - the role was not considered exclusively a black role until the smash hit Theatre Guild production in 1943 with the great Paul Robeson in the role and recorded more or less complete by Columbia Records to influence generations to come including the *other* best filmed OTHELLO, Laurence Olivier in his more traditional production) leading essentially white Venetian troops against the Moslem Ottoman Empire. The dynamic still works here, but we lose half the xenophobic subtext with a Cassio (the lieutenant promoted over the play's true lead, Iago, and holding equal position in Iago's enmity for being a "Florentine arithmetician" - ie. a foreign born, educated man, not a battle trained native Venetian soldier like Iago) who is not also an outsider (the plot essential role and the moving Sean Baker aren't even MENTIONED on the DVD box!).
The great opera performer Willard White gives a solid Othello - more grounded than Olivier's a quarter of a century earlier, not feeling to obligation to follow the Robeson template (unfortunately also less fiery), but while the title role is the one productions are mounted for, any OTHELLO finally stands or falls on its Iago, and Ian McKellen is entirely up to the task. He lacks the Oscar nominated burly charisma of Olivier's Iago, Frank Finlay, but he is just as quietly insinuating in his own right and perfectly matched with the lower key Othello of White and Imogen Stubbs less confident, more gentle Desdemona. Director Nunn makes a point of bringing McKellen even more to the fore for the kind of sharp charisma he does have, breaking the fourth wall in his narrative monologues to the audience which somehow seem even more personal than Finlay's. Paired with McKellen's other great (and frequently time shifted) filmed Shakespearean performances in RICHARD III (against a 30's Fascist background) and his one man show ACTING Shakespeare, this OTHELLO, originally broadcast as part of the BBC "Theatre Night" series on 23 June 1990, becomes a must see and the DVD release from Image Entertainment very welcome.
The supporting cast is uniformly first tier - most especially Zoe Wannamaker's Emelia (Iago's faithful 'till the end wife).
For filmed Shakespeare honoring the original text, OTHELLO has actually been offered more than most of the rest of the Bard's canon (is "the green-eyed monster" Iago conjures up really so universal?), but probably the best examples (since Paul Robeson sound-alike James Earl Jones' 1982 Broadway run - "produced in association with CBS Video Enterprises" - was somehow not preserved) remain Olivier's National Theatre production from '65 and this 1990 Royal Shakespeare Company production. The choice boils down to whether you're in the mood for a production in the period and with the look close to the original or a "modern" interpretation. Either is excellent and both essential for a full understanding of the power of the work.
I'd even toss in Orson Welles' highly stylized 1952 "movie-movie" for the long neglected "NON-blackamoor moor" interpretation of the role (Welles, probably America's greatest Shakespearean interpreter as actor and director on stage, couldn't pass for a black man on his best day).