问为什么我不能将透视相机配置成三个js内的实际尺寸？

EN

var camera, scene, renderer, mesh, material, stats;
init();
animate();

function init() {
    // Renderer.
    renderer = new THREE.WebGLRenderer();
    //renderer.setPixelRatio(window.devicePixelRatio);
    renderer.setSize(window.innerWidth, window.innerHeight);
    // Add renderer to page
    document.body.appendChild(renderer.domElement);

    // Create camera.
    camera = new THREE.PerspectiveCamera(70, window.innerWidth / window.innerHeight, 1, 10000);
    camera.position.z = 400;

    // Create scene.
    scene = new THREE.Scene();

    // Create material
    material = new THREE.MeshPhongMaterial();

    // Create cube and add to scene.
    var geometry = new THREE.BoxGeometry(200, 200, 200);
    mesh = new THREE.Mesh(geometry, material);
    scene.add(mesh);

    // Create ambient light and add to scene.
    var light = new THREE.AmbientLight(0x404040); // soft white light
    scene.add(light);

    // Create directional light and add to scene.
    var directionalLight = new THREE.DirectionalLight(0xffffff);
    directionalLight.position.set(1, 1, 1);
    scene.add(directionalLight);

    // Add listener for window resize.
    window.addEventListener('resize', onWindowResize, false);
    
    // Add dat.gui.
    var gui = new dat.GUI();
    var fovgui = gui.add(camera, "fov").onChange(function(newvalue){
      camera.updateProjectionMatrix();
    }).name('camera.fov');
    var posgui = gui.add(camera.position, "z").name('camera.position.z');
    
    gui.add({click: function(){
      camera.fov = 5;
      camera.position.z = 5000;
      camera.updateProjectionMatrix();
      fovgui.updateDisplay();
      posgui.updateDisplay();
    }}, 'click').name('FOV:5 Z:5000');
    
    gui.add({click: function(){
      camera.fov = 70;
      camera.position.z = 400;
      camera.updateProjectionMatrix();
      fovgui.updateDisplay();
      posgui.updateDisplay();
    }}, 'click').name('FOV:70 Z:400');
    
    gui.add({click: function(){
      camera.fov = 130;
      camera.position.z = 190;
      camera.updateProjectionMatrix();
      fovgui.updateDisplay();
      posgui.updateDisplay();
    }}, 'click').name('FOV:130 Z:190');

}

function animate() {
    requestAnimationFrame(animate);
    mesh.rotation.x += 0.005;
    mesh.rotation.y += 0.01;
    renderer.render(scene, camera);
}

function onWindowResize() {
    camera.aspect = window.innerWidth / window.innerHeight;
    camera.updateProjectionMatrix();
    renderer.setSize(window.innerWidth, window.innerHeight);
}

body {
    padding: 0;
    margin: 0;
}
canvas {
  display: block;
}

<script src="https://cdn.rawgit.com/dataarts/dat.gui/master/build/dat.gui.min.js"></script>
<link href="https://cdn.rawgit.com/dataarts/dat.gui/master/build/dat.gui.css" rel="stylesheet"/>
<script src="https://cdn.rawgit.com/mrdoob/three.js/master/build/three.min.js"></script>