Aturan kode css nya:
img{
opacity:.50;
filter:alpha(opacity=50);
filter: "alpha(opacity=50)";
}

The css rules:
img{
opacity:1;
filter:alpha(opacity=100);
filter: "alpha(opacity=100)";
}

aturan kodenya:
a:hover img{
opacity:.40;
filter:alpha(opacity=40);
filter: "alpha(opacity=40)";
}
aturan kodenya :
a img{
opacity:.40;
filter:alpha(opacity=40);
filter: "alpha(opacity=40)";
}
a:hover img{
opacity:1;
filter:alpha(opacity=100);
filter: "alpha(opacity=100)";
}
Berikut kode yang bisa digunakan:
opacity:.60;
filter:alpha(opacity=60);
filter: "alpha(opacity=60)";
}
Hasilnya:
Css property opacity 100
Css property opacity 60
Note: Untuk browser versi lama masih menggunakan ‘-moz-opacity’.