Dallmeyer Patent Portrait B Series

Petzval lens with soft focus adjustment.

Early Dallmeyer B series petzval lenses have rack and pinion movements, soft focus adjustment by unscrewing rear lens. Later modification -rigid setting, soft focus control by turning lens barrel (Turn for soft focus).

 
No Diameter of glass elements Focal Length Format
Dallmeyer 1B 50mm (2″) 152mm CdV
Dallmeyer 2B 70mm (2 3/4″) 210mm CdV
Dallmeyer 3B 90mm (3 1/2″) 275mm Cabinet
Dallmeyer 4B 115mm (4 1/2″) 430mm 81/2×61/2

Dallmeyer petzval B series