// make light's shadow softness fade out really fast
    light.shadowSoftnessFade = 0.3;

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void Example() {
        light.shadowSoftnessFade = 0.3F;
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def Example():
        light.shadowSoftnessFade = 0.3F