Carson was late night's last true love

It is still hard to watch footage of Johnny Carson's farewell show without a moistening of the eyes.

On the evening of May 22, 1992, The Tonight Show host Johnny Carson hop-skipped through the curtains at the NBC studios, gave a little bow and held up his hands to hush the crowd, as he always did. "Thank you," he said. "Thank you." He must have said thank you 30 times that night, with little effect. The audience just wouldn't stop clapping. "We love you," somebody cried when the racket finally started to die down. "I love you too," Carson replied.

The relationship between celebrities and their fans tends to be fickle - today's undying devotion is tomorrow's disregard. The connection between Carson and the American public was a rare exception. People really did love Johnny, and Johnny really did love them back. You could see it in his face as he flapped his arms on the stage that night, trying to get a word in. Even today, it's hard to watch this clip without welling up. This was the last time Carson would host The Tonight Show, three decades and 22,000 guests since he'd first stepped onto the stage. Something like 50 million viewers had tuned in to watch as he began his final opening monologue: "Look on the bright side - at least you won't have to read or see one more story about my leaving the show."

Until recently, this reel and the thousands of others Carson recorded were stored in a disused salt mine in Kansas (Carson, who died in 2005 at the age of 79, would have had fun with the salt-mine bit). This month, though, the Carson Entertainment Group announced that the surviving Tonight Show archive (videos for the first decade of the programme, sadly, were taped over by frugal NBC execs) has been digitised.

While this won't make much of a difference to regular Carson fans - for now, the digital library is only available to industry professionals, such as producers wanting to use a clip of the show in a film - Carson Entertainment plans to release 50 episodes on DVD, and will also upload some of the clips onto johnnycarson.com, which is a wonderful thing, even if the majority of people under the age of 50 don't know it.

There was a time when Johnny Carson was the most famous name in US television. Even today, as we approach the 20th anniversary of his final show, he remains massively influential. In its heyday, an appearance on The Tonight Show was a prerequisite for anyone hoping to break into TV. Not only did Carson cast the mould for the likes of David Letterman and Jay Leno, he introduced them to the world. But Carson's influence went beyond this. While late-night talk had existed before he came along, nobody had done it quite like him. In the early 1960s, chat shows were still starched and scripted affairs, once removed from their audiences. Carson changed all that. He was spontaneous and informal. He made viewers feel as if they were somehow there. This was part of his appeal: it was like being invited to a great party.

And nobody enjoyed these things more than Carson, which brought his audiences closer still. One of the things we loved about Johnny is that he spent as much time laughing as he did cracking jokes. There were times when he'd be helpless with it, unable to do his job. And his guests picked up on this, too - people were always at their funniest and most charming when they were on The Tonight Show. Even contemporary masters of late-night have failed to recreate this quality. Letterman's a little too abrasive to put his guests fully at ease, Leno's a touch too smug. Worse yet, the new generation of hosts - the likes of Jimmy Kimmel and Chelsea Handler - deliberately rub people the wrong way. Carson very often teased his guests, but these guys taunt them. Late-night audiences, meanwhile, continue to dwindle.

Johnny Carson ushered in the era of late-night talk, but he also made life difficult for those who followed - you could say that the genre peaked too soon. In this regard, his final show marked the beginning of a long decline. This fact makes Carson's recent debut into the digital arena even more of an occasion, and it makes clips of that show even harder to watch. Carson was too much of a pro to cry on that last night. There was grief on his face, but he didn't crack. Instead, he simply perched on that stool of his, as he always did in the dying seconds of the show, and quietly bid his audience goodnight.