The art of the Wyeths. After touring the USSR, a three-generation exhibition is on view in the US before going on to Japan, Italy, and England

``The problem with having the name Wyeth is that, immediately when people hear the name, they all of a sudden see weathered barns in a field or something,'' says Jamie Wyeth, a third-generation painter in the family of famous artists. Jamie - formally James Browning Wyeth - has strolled down the scarlet carpeted staircase for an interview at the Corcoran Gallery of Art, where ``An American Vision: Three Generations of Wyeth Art'' has just opened. This triple-hitter exhibition celebrates the work of his grandfather, artist-illustrator N.C. Wyeth, and of his father, Andrew Wyeth, as well as the paintings of Jamie Wyeth.

``Well, my father certainly exploded that theory [of weathered barns] in the last few months. I mean, he's been painting something other than barns,'' says Jamie, with a small laugh.

He is talking, of course, about the controversial ``Helga Collection,'' 125 pictures of the model whom Andrew Wyeth painted secretly for 15 years. The Helgas are now packing in crowds of thousands across town at the National Gallery.

The Corcoran show, with its 115 paintings stretching over a century in American art, coupled with the Helga show, has resulted in the Wyeth-izing of Washington this summer. One hotel is even offering ``Wyeth Weekends'' in its ads.

Jamie Wyeth shrugs off the publicity. ``We, of course, have always fought against having shows like this, even though museums have gone ahead and done it without our participating. But they were so serious about the intent of this. ... I've always stayed away from this - it's sort of like the [Flying] Wallendas, the Wallendas of Painting. And then the Russian thing did it - really made this a serious endeavor.''

The ``Russian thing'' was the decision to make the Wyeths exhibition the first traveling show of American paintings to be seen in the Soviet Union, following the cultural exchange program agreed on at the Geneva Summit in November 1985. Some 3,000 Soviet citizens a day lined up to see the show, during the tour of Leningrad and Moscow, from which it has just returned.

The Corcoran exhibition, which runs through Aug. 30, marks the beginning of its American tour. From here, it will travel to four cities in the United States and three abroad: Dallas (Sept. 29-Nov. 29); Chicago (Dec. 13-Feb. 14, 1988); Tokyo (March 10-April 28); Milan, Italy (May 17-June 20); Cambridge, England (July 12-Aug. 29); and finally back to Wyeth country, Chadds Ford, Pa., where the Brandywine River Museum organized and circulated it.

The spokesman for the family, Jamie Wyeth, has the same sort of handsomely dramatic face his grandfather painted in ``The Torrent in the Valley of Glencoe,'' shown in this exhibit. But rather than the Scottish kilt of that painting, Jamie Wyeth wears a businesslike navy blue suit, royal blue and white striped shirt, and navy polka dot tie. The clear white light of a summer afternoon comes through the windows of the former museum studio where we talk.

Jamie Wyeth says that there is ``a certain continuity'' running through the show. ``Maybe it's just ... that we happened to be raised in the same areas'' - Chadds Ford and Maine. ``But I think our approaches are quite different.'' He hesitates. ``The only thing that really runs through is that we take painting very seriously. That is what we live and breathe for.''

The show at the Corcoran plunges the viewer into three exciting but diverse worlds: N.C. Wyeth's gripping illustrations of King Arthur and characters from ``Treasure Island'' and ``Robin Hood''; Andrew Wyeth's familiar temperas, dry-brushes, and watercolors of Pennsylvania and Maine landscapes, the Kuerner family, his models Siri and Helga (there are three Helgas here), and such landmark paintings as ``Weather Side''; Jamie Wyeth's world, which runs from the celebrated portrait of John F. Kennedy to ``Draft Age,'' seascapes like ``Sea of Storms,'' his self-portrait as pumpkin head, and his evocative portraits of his wife, Phyllis.

Jamie Wyeth says of his father and grandfather (who died the year before he was born):

``My father's like - it's as if he was transparent. He's a man of great mystery, whereas apparently N.C. Wyeth was 6-feet, 2-inches tall, with a booming voice. I think that's reflected in their work. My father's work is rather mysterious, not much said, and my grandfather's is robust, bursting off the walls.''

The executive director of the Corcoran, Edward Nygren, compares and contrasts the three: N.C. Wyeth, he says, ``is much more painterly; that is, you have a real sense of the pigment, and he's mostly interested in using oils. I think you have a fairly dramatic presentation of the subject matter with a very rich color ...., to get across the drama of the particular scene he's depicting.''

Andrew Wyeth, says Mr. Nygren, ``is much more linear. He harks back more, it seems to me, to the Renaissance in his emphasis on line to create form, as opposed to color to create form. [He] has a much more restricted palette, frequently grays or very subtle tones.

``Jamie Wyeth ... sort of blends a little bit of both. Certainly there's a keen awareness of the importance of line to create form, but ... there's also a kind of sensual relish with the manipulation of paint. Andrew's paintings almost have an awesome sense of stillness about them. I wouldn't say just loneliness; there's a stillness about the figures and about the landscape. With Jamie, there's a vitality and an action in the surface and a movement in the forms and in the subject matter.''

Does the mantle sometimes hang heavy on Jamie Wyeth, as the third generation of a family of famous artists?

``It does,'' he admits. ``But, you know, once [I'm] in my studio, that stays outside the studio door. It has nothing to do with what I'm working on right now.'' He adds, ``The mantle isn't so heavy, really. But I wouldn't want to wish it on a fourth generation....'' He trails off with a small laugh.

Why not? ``Well, I know some children of people that are in the same field, and it can work adversely. I don't know why it never worked adversely with me. Sure, there are problems. There are drawbacks and whatnot. You're constantly compared. But I found the painting was so insurmountably difficult to do that everything else was secondary to that. The whole consideration of - ... am I being compared as such and such's grandson and son - that was minuscule compared to the problems I was having just working. ... I didn't have time to start worrying about who I was in the eyes of the public.''

Would he paint if he hadn't been born a third-generation Wyeth?

``I think I would. If my name were Brown, and I were born in Des Moines, Iowa - I think yes, I would. ... Nothing gives me a bigger rush than when I'm painting, or when things are working in painting. So I can't imagine not having that urge.''