Quote Originally Posted by laz127
Begin back-peddling: I did a quick Google of this lens. I didn't get the AIS version, but I did find this very interesting review:

Nikon actively developed their fast normal lenses throughout the '70s. The coatings were improved and the basic double-Gauss formula was trimmed to squeeze even better performance out of the 50/1.4. The last version before the AI epoch featured a shimmering red front element and sported a very capable performance. Wide open there is some softening in the corners that disappears by f/2.8, At f/4 it gives excellent images, and the quality stays basically the same up to f/8. Beyond that f-number the performance declines perceptibly. Flare levels are low, but ghosting can be provoked by pointing the lens towards bright light sources.

Well shut my mouth!

Link to the review:
http://www.naturfotograf.com/lens_norm.htmlNikon
"Softening in the corners" isn't what most of us think of as vignetting. Vignetting usually means dark corners. Here's an example. Very compressed, looks awful, should make the point anyway.