Benson's 'Places in the Heart': sound sentiment, clear sincerity. Also, 'All of Me' is silly; 'Windy City' wavers

''Places in the Heart'' is sentimental from the moment the title hits the screen. But it's a nice kind of sentimentality, based on real affection for the characters and real involvement with a place and time - Texas at the height of the depression - that lingers halfway between memory and history.

The story, which is regrettably slight, focuses on a sheriff's wife whose husband abruptly dies. Left with young children and no way of supporting them, she faces up to hard situations, coping so well that she's surprised at her own strength. Other characters include her strong-minded sister, the sister's philandering husband, a blind man who boards at her house, and a black drifter who becomes her aide and adviser.

Held loosely together by its slim plot, the movie jumps from one Big Scene to another, giving each an unusual share of care and attention. Some don't advance the story much, but are gripping while they're on the screen - a tornado sequence, for example. Others are quite imaginative, as when the blind character must defend his black friend from a Ku Klux Klan attack. The climax is a cotton-picking episode that vaguely recalls the classic ''Our Daily Bread,'' with just about everyone in the movie scuttering through the fields in a desperate race against time.

''Places in the Heart'' was written and directed with clear sincerity by Robert Benton, known mostly for ''Kramer vs. Kramer'' a few years back. Although his visual style isn't particularly original, he has a good eye for details and shows a commendable willingness to take real risks now and then. This derring-do pays off most richly at the end of the film, when he dismisses the story's realism without telling anyone, and glides into a superbly conceived camera movement that links all the characters into a moment of transcendent harmony. It's corny, in a way, but there hasn't been a more touching moment in any film this year.

Headed by the versatile Sally Field, the cast of ''Places in the Heart'' is almost a convention of Hollywood's best character actors. Lindsay Crouse is firmer and less mannered than usual as the sister. Ed Harris, a major asset of many recent pictures, is quietly authoritative as her husband. Danny Glover has the right mix of humor and sad vulnerability as the black helper. Lane Smith and Bert Remsen show up in small roles. And the amazing John Malkovich, so intense in the fine ''Death of a Salesman'' on Broadway, works wonders with his offbeat blind-man part.

A special nod also goes to cinematographer Nestor Almendros, whose collaboration with Benton - this is their third film together - shows signs of approaching the photographic heights of his work with Francois Truffaut and Eric Rohmer. Here's hoping the partnership continues to ripen and mature.

'All of Me'

''All of Me'' doesn't just pair up Lily Tomlin and Steve Martin, it runs them together through a comic Mixmaster.

Tomlin plays an eccentric millionaire who sees no reason why money can't buy immortality. Waiting eagerly for death, she has a Tibetan guru waiting to transmigrate her spirit into a younger and prettier self.

Martin plays a jazz-loving lawyer who despises her imperious ways. When her big moment comes, the guru goofs and the transmigration misses its target - leaving two mutually loathing people to share the same crowded body.

It's a ridiculous story, and the screenplay (by Phil Alden Robinson) stuffs it with low jokes and bathroom humor. Yet a number of scenes are sly as well as silly, and director Carl Reiner knows when to inject a little pathos for a change of pace. He also uses touches of jazz that lend a gentle rhythm the movie would otherwise lack.

It's the acting, though, that boosts ''All of Me'' a cut above the average Reiner movie. Steve Martin (in his fourth Reiner collaboration) gives the first well-rounded performance I've seen from him, playing the serious moments with genuine warmth, then spinning into the most extravagant physical humor this side of the late John Belushi. Tomlin makes the most of her opportunities, too, though her role isn't so strong. Victoria Tennant is properly insinuating as the intended recipient of the mixed-up spirit; Jason Bernard swings along nicely as the lawyer's jazzed-up friend; and Selma Diamond is golden as a put-upon secretary.

'Windy City'

In the first shot of ''Windy City'' a bunch of kids are cheering a pirate movie on TV. A few minutes later they're all grown up, but still the same old gang, caring more for fun and companionship than adult responsibility. From the look of things, we're in for another brash look at arrested development a la ''Diner.''

But the shots are edited to a slow beat that signals something different. And sure enough, the central love story - between a would-be writer and a new woman in town - turns out to be choppy and bittersweet, recalling the underrated ''Chilly Scenes of Winter.'' Meanwhile the hero's best friend, a key member of the old gang, has just found out he's dying.

Which will win - the comic and comradely part of the plot, or the sad developments? Unfortunately, it's pretty much a standoff. It's hard to take the love problems too seriously with so many buddies to offer fun and distraction. It's also hard to settle back and laugh, with poor Sol expiring before our eyes.

The picture might work better if it were more carefully scripted. Big chunks of information are missing: Why did the guy and girl break up? What are her goals and aspirations? What sort of man is the faceless character she's about to marry? Armyan Bernstein, who wrote and directed ''Windy City,'' leaves us in the dark.

On the other hand, the movie's unrushed pace is refreshing after months of ''Indiana Jones'' and ''Bachelor Party'' at the top of the charts. And the performances are uncommonly gentle. Kate Capshaw (in her fourth picture this year, by my count) brings quiet charm to her underwritten role, while Josh Mostel is just right in the difficult Sol part. Of the three leads, only John Shea underplays to the point of passivity.

Despite all its down moments, ''Windy City'' does work up to a happy ending - although it's such a close call that the movie actually announces the fact, in case we didn't realize it. But director Bernstein pushes the mood too much, until what might have been warm and subtle becomes soggy and manipulative. The movie's heart is in the right place, but its methods don't match its intentions.