STARTING TOMORROW in Detroit, the Republican Party will for a week stage an opera bouffe, or perhaps with its cast of stock characters a commedia dell'arte, which may be of some benefit to itself, but will be performed largely for the benefit of the television networks.

The people who will derive no benefit at all are the viewers. They may have a few glimpses of unknown figures like Paul Laxalt or Richard Lugar when they are ushered on stage as pantaloons, and may even for an ecstatic moment feel that they are present at the ascension of Ronald Reagan, but for the most part they will merely have the chance to take a longer look at the mannerisms of the television anchormen and reporters. They may also begin the painful national catharsis which will accompany the retirement of Walter Cronkite.

It would be of some interest and a fair test of the seriousness of the occasion to ask the viewers at the end which state is represented by Richard Lugar and in which of the two houses of Congress. I suspect that they would be equally divided in saying that he worked for NBC or ABC or CBS, with some difference as to whether he worked on the convention floor or in the glass boxes of the anchormen.

It was at the last Republican convention that Walter Cronkite brought together in his glass box no lesser figures than Barry Goldwater and Nelson Rockefeller, who was then the vice president of the United States, so that they might bring to an amiable if pathetic conclusion on television the bitter feud which had erupted on the screen at the Republican convention a dozen years earlier.

The two men seemed almost palsied with age as they were jollied along by the pin-striped figure to whom they abjectly deferred as if he were their president, until at last there came the benediction as Walter Cronkite forgave them their past sins and genially but superciliously patted the vice president on the knee.

As the cameras dwelled for a last moment on the two grateful old men and their confessor, one could hear swelling round his hallowed head the holy chant of the Nunc Dimittis. We had been present at an evensong.

It is the besetting fault of the television coverage of the conventions that we are allowed to see and hear only snatches of its proceedings. The purpose and real life of a convention are in more than its decisions, even its choice of a candidate for the presidency, for this is a party brought together once in four years to rediscover something of its identity.This is when we should be reminded of the labor and patience and concerns of the little known. A party convention used to breathe in its long, straggling debates. But all we are permitted by television to hear are the set pieces. We are allowed to listen only to the Knowns, as Herbert Gans calls them in his book on television news coverage.

Instead of a steady coverage of the proceedings, we must follow the television reporters as they scurry about the convention floor with their silly two-way radios, and the even sillier antennae sprouting from their heads, like goblin men from Mars or even a more distant planet (which they might well be, so tenuous is their connection with the actuality of what is going on in the convention hall). These reporters eventually feed on each other's stories, as one starts a rumor that there is a groundswell for some Known, and the others dart around to find that there is nothing in it.

It is in the nature of most important events to be dull, and by its nature television cannot handle the dull. Newspapers can bring the dull alive by good writing. To take but one example that springs to mind, Helen Dewar of this newspaper can take a complicated debate on an elaborate amendment to a difficult piece of legislation, and by her ability to write well make it intelligible. Television is quite unable to do that and, although there is blame to be put on the business side of the networks, and on the kind of audiences which the advertisers want, the real fault lies ineradicably in the camera.

For example, most important events take place where the camera cannot reach, in private. This is ultimately not an obstacle to newspapers. They can usually gather at least some sense of what has taken place, and with the aid of words they are able to give some fairly accurate and even readable account of it. But at a reporter spouting words for any length of time the red eye of the camera blinks.

The camera can report a strike -- there are pickets, there are rallies; with good luck, there will be violence -- but finds it hard to report a negotiation. The camera must stop at the door and, even if a reporter gets inside to get the story, the camera pouts and will not let him speak. The camera needs a happening, preferably a volcano in eruption. It cannot deal with the intricate gathering of a complicated event.

It is hard to convince anyone who has not worked for television of the extend to which the camera gets in the way. At the time in one's life when school bills press and the milk bills are large, I was willing to hire myself out as the reporter on television documentaries in England. They covered a variety of subjects, such as the Algerian war, the Berlin Wall, the Common Market and the British police, and I was open to the challenge of a new medium. But in the end I gave it up, because the camera always won.

In an article which I wrote at the time for Encounter, giving the reasons for my withdrawal, I said that I always wanted to say at the beginning of each program, "You are about to see some nice pictures. But they have nothing to do with what I will be talking about." Some years later, before an audience of American students, I drew as prolonged applause as I have ever done, when I encapsulated this observation in the statement: "If you see it on television, it has not happened."

It is monstrously untrue that the camera cannot lie. It is the most eager and pliant of liars. I used to sit behind the shoulder of the film editor of my documentaries as he ran the raw videotape through the machine. Every now and then he would stop the machine, wind back the tape, play it again, say, "That's a good sequence," and jot down the footage. I would protest that it had nothing to do with what I was saying. "I cannot help that," he replied with finality, "it's the best footage we've got." The camera had won again.

I have always believed that the still camera lies, but that can be left aside for the moment. What is undoubtedly true is that the motion camera lies. Its nature is what its name says. Motion. It needs action, and of a particular kind. What it records best is a club coming down on a head -- that is television -- and it is not above arranging for clubs to come down on heads. It is adept at catching the moment of police brutality. That fits nicely into the alloted 1 minute, 15 seconds. (What is laughably called in-depth treatment is allowed 1 minute, 45 seconds.) But the long hours of provocation that yielded that brutality? The camera hasn't the eye for that.

It is now generally agreed that Martin Luther King Jr. -- and it is no criticism of him -- knew precisely what television added to passive resistance. You stood in your thousands for long, threatening, sweaty hours at the approach to Selma bridge. Hostility hung and hissed in the quivering heat. Television news did not have the time to show that. You stood there until at last down came the clubs and forward sprang the dogs. Television has exactly the time for that and the camera waits for it.

It may seem that the problems in covering a convention are different -- after all, there are the reporters, although not the delegates, talking words -- but they spring from the same basic nature of the camera. The words of the television report on the convention floor are really forms of action. That is why they are always jumping about in their goblin suits with their goblin antennae. Since there is no action, their action is manufactured. "Are you there, Morton?" "Back to you, Walter."

One sees them more than one hears them. The proof of this is that we are never more electrified than when the reporter is speaking but the sound has failed. We watch stupefied as the reporter mouths. "We've got Morton back now," says Walter, and we are bitterly disappointed. If any network wishes to raise its ratings for its convention coverage it should arrange for regular breakdowns in the sound.

I often wonder how these usually intelligent reporters keep either their sanity or their self-respect in television year after year. Perhaps they don't. Perhaps that's why they jump up and down so much. Roger Mudd is in my judgment one of the few television reporters who regularly wins over the camera. He may not appreciate the compliment, but I am glad that CBS slighted him. Anchormen are two a penny -- or Rather, so to speak, a million -- but reporters who dominate the camera are rare.

It may not really matter all that much -- the impact of television is immediate, so perhaps it is as superficial and transient -- as long as people know what it is not giving them. What they will not see on television this week is politics. What they will not see is a party. What they will not see is its convention. What they will not see is how serious issues come to the surface in politics and are decided. They will not see even shadows of these, but only a relentless traducing of them. My statement can be turned around, and it's almost as true: "If it happened, it won't be on television."

Since the camera will not cover their real proceedings, the parties have more or less thrown in the sponge. What television wants, they will provide. At the Republican convention which renominated President Nixon, an actual script for the convention was prepared and then followed. (And discovered by a reporter.) As Malcolm Muggeridge says, you cannot caricature life anymore. It is a parody of itself.

You may wonder why the news operations of the networks moved early to Detroit. They will tell you that the politicians were already there, and that they had to set up their truckloads of circus gear. Both reasons are only partially true. They were primarily there so that the politicians could adapt their proceedings to the demands of the television script. They were there to write and release it.

What will it all come to? I forget who said that the world will not end in a bang, or even in the whimper of Eliot, but with everyone in one vast Hilton hotel watching it on television. Television itself will by then have become one endless "Today Show," from which the last trace of actuality has been erased, and it is already a "Today Show" to which the conventions have been reduced.