back when i first started this obsession called photography, my dad gave me his old nikon EM and three lenses. i thought they were all series E lenses (28mm f/2.8, 50mm f/1.8, 100mm f/2.8). today i was cleaning these lenses to get ready to sell them (watch the for sale forum!) and i noticed that they all said 'series E' on them, all but the 28mm. here it is: what version is this lens? i can't seem to find any answers. thanks in advance!