drecon-unity/Assets/LensOscillate.cs

using Cinemachine;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class LensOscillate : MonoBehaviour
{
    public CinemachineVirtualCamera m_VirtualCamera;

    public float m_Speed;

    [SerializeField]
    private float m_FOV;

    private float m_SineValue = 0;

    private float m_Time;


    // Update is called once per frame
    void Update()
    {
        m_Time += Time.fixedDeltaTime;
        m_SineValue = Mathf.Sin(m_Time * m_Speed);
        m_FOV = Map(m_SineValue, -1, 1, 0.2f, 0.45f);

        m_VirtualCamera.m_Lens.OrthographicSize = m_FOV;

    }

    private float Map(float x, float x1, float x2, float y1, float y2)
    {
        var m = (y2 - y1) / (x2 - x1);
        var c = y1 - m * x1; // point of interest: c is also equal to y2 - m * x2, though float math might lead to slightly different results.

        return m * x + c;
    }
}