<style type="text/css">
<!--
.transparan img{
filter:Alpha(opacity=80);
-moz-opacity: 0.4;
}
.transparan:hover img{
filter:Alpha(opacity=100);
-moz-opacity: 1;
}
-->
</style>
Kullanımı :
<a href="#" class="transparan"><img src="resim.jpg" border="0" id="foto"></a>