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:
"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.