Quote Originally Posted by Raphael View Post
Hi all,



Hello Mr Fromm,

Glad to see you in this thread !

That's the first name which came in my mind when seeing the handwriting, however, IMHO (and I also asked to the Lady-to-my-side as second opinion), it's Berthier, or maybe Berthiès :
Attachment 69917

BTW, I just read your articles series about "Unlikely lenses on Speed Graphics" with great interest


@John : Yes, it's look a little a Tessar, but reversed, as the cemented doublet is in front

Trying to make things clearer, if I can make a crude chart with ASCII art, it would likes this :

------------> (|| ))I|)

Incoming rays, Front group, rear group

Front group : cemented doublet (not sure if the last surface is actually plan)
Rear group : Concave-Convex thick lens, a spacer ring (symbolized by the I) about 5mm thick, and thin plan-convex lens (not sure again if it's really plan).

@shutterfinger : thanks for your reply, it's hard to tell, but maybe it's effectively a "B". Do you know if Lacour-Berthiot ever used this kind of monogram with the star ?


Thanks again to you all !

Cheers,

Raphael
maybe it is a reversed tessar because light travels through the lens
opposite with a camera than when projected ?

looks like a fun objectif

john