如何在我的leaflet代码中修改图像的不透明度

<link rel="stylesheet" href="https://unpkg.com/leaflet@1.7.1/dist/leaflet.css" />
<script src="https://unpkg.com/leaflet@1.7.1/dist/leaflet.js"></script>

<div id="map" style="width: 100%; height: 400px;"></div>
<script>
    var map = L.map('map').setView([51.505, -0.09], 13);
</script>

var imageUrl = 'path/to/your/image.jpg';
var imageBounds = [[51.49, -0.08], [51.51, -0.06]];
var imageLayer = L.imageOverlay(imageUrl, imageBounds, { opacity: 0.5 }).addTo(map);

imageLayer.setOpacity(0.8); // 设置不透明度为0.8（80%不透明）