Nikkor 50mm f1.8e vs pancake?

I have a 50mm f1.8e lens. When I look at images of it on the internet it looks exactly like the 50mm f1.8 pancake. Are the two lenses the same? If not, are there differences? Thank you.

Same optical formula, different coatings. "Nikkor" branding instead of "Nikon Series E".

Nikon | Imaging Products | NIKKOR - The Thousand and One Nights No.60

There is also a difference in minimum focus distance. The 50/1.8s pancake in Dieter's link above (originally sold only in Japan, s/n 2050001 and up) has a 0.45m minimum focus versus 0.6m for the Mk.II chrome ring version of the Series E (s/n 1900001 and up). The final version of the AiS 50/1.8 Nikkor exported worldwide (s/n 4000001 and up) shared the 0.6m minimum focus of the Series E.

 

There are also differences in internal construction. The Japan 50/1.8s pancake has all metal helicoids. The chrome ring Mk.II Series E (and final AiS 50/1.8 Nikkor) has metal (3) and plastic (1) helicoid threads.

 

The Japan pancake and Mk.II Series E has a metal focusing ring. The final AiS 50/1.8 Nikkor has a plastic focusing ring. The Japan pancake has a metal aperture ring, the other two have a plastic aperture ring.

 

See Roland Vink's excellent database here:

http://www.photosynthesis.co.nz/nikon/lenses.html#50slow

Edited January 2, 2022 by Michael R Freeman