(there was a url link here which no longer exists) - Peter Karbe holding Max Berek Notebook- 1922 Lens Design Recipe recorded from video
Max Berek 1922 Lens design attached with all strange numbers.
Peter Karbe , Leica Chief Designer gave a interview about apo summicron.
He was talking about the 100 year tradition of Leica and his following the old Leica designers.
And he started to talking about worlds first 50mm lens designed by Max Berek.
NoteBook was
Angaben über Optik der Rechenabteilung Prof.Berek für Konstrüktionsbüro Engelmann