On Wed, 17 Jun 1998 21:38:42 +0800, ET & RL wrote:

>Someone is selling me the Nikkor 180mm 2.8 ED lens.
>Can anyone educate me what ED means?
>How would you rate and use this lens?

The Nikkor ED lenses are uniformly excellent (barring
sample variation). You can look at my Nikkor evaluation
list on my web page, under "I babble" for my opinion
of this lens compared with other Nikkors. The ED glass
serves to reduce chromatic problems, most useful in fast
teles. The ED glass is affected by temperature changes,
causing focus shift (which is why the lens will appear
to focus beyond infinity [neat concept, huh?! ;-]). BTW,
if the front element is ED glass, be careful with that
(icky...!) "canned air" - uneven rapid cooling of an ED
element can cause it to crack.