In article <19970405234500.SAA05882@ladder01.news.aol.com>, rickt72267@aol.com says...

>Is the glass on this lense as good as the non series E 50mm 1.8 ?
>I understand the mount is not as well made as a non series E. Is that the
>only difference ? Thanks for the help.

The optics are different, unless the barrels look similar (the "plastic"
AIS and the rare compact metal-barreled AIS had the same optics as the E,
but were multicoated [the E wasn't]). The E is a tad (but only a tad, in
a good sample) less sharp, but the E also has no linear distortion, the
non-E large-barrel 50mm f1.8 does... I wouldn't worry about the
differences (leave it to the lens nuts, like me...;-).
Hope This Helps