Hello Mr Fromm,
Originally Posted by Dan 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 :
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 !