I've talked before about how crying scenes in scripts can often come off as overwrought and melodramatic. It's something that crops up a lot in screenplays and I can understand how it happens. Writers are told to show, not tell - so when it comes to someone's emotional state - why wouldn't you have them break down in a crying fit to demonstrate that they're sad?
One reason not to do so is that with film, the audience can be manipulated into a position where they'll project their own emotions onto the character. Thus, the character doesn't need to oversell the emotion - all they have to do is provoke the emotion in the audience.
In re-reading The Making of Star Wars by J.W. Rinzler, I came across an excellent example of this theory. On p. 149, the scene where Luke returns to his uncle's farm to find his aunt and uncle killed by stormtroopers is discussed. It's noted that Mark Hamil wanted to play the scene with him falling on his knees sobbing in despair upon discovering the corpses. Director George Lucas insisted on a more neutral performance. "Lucas knew that later he would edit the sequence in keeping with the art of montage as explained by early Russian filmmakers such as Sergei Eisenstein and Lev Kuleshov, in which the juxtaposition of shots would arouse emotion rather than just the actor's performance."
You can find more about the Soviet montage theory here.
Now, as writers we're not supposed to call out each shot, doing the directors job for them. However, in writing the description you can subtly suggest the imagery and editing. For example, the description for the scene in question might read:
Luke's speeder arrives at the Lars farm. Luke gets out, rushing towards the homestead.
Smoke rises from the enclosure.
Luke runs closer than stops, frozen with surprise.
Two corpses lay sprawled amid the carnage, their skin burned completely off.
As the smoke continues to rise in the sky, Luke casts his gaze downward, processing his loss.
It's easy not to overwrite dialogue, but not overwriting emotion takes a defter touch.
