Dallmeyer Patent Portrait A Series

Dallmeyer petzval lens with F ratio 1:4.

No Diameter of lens elements Focal length Recommended format
Dallmeyer 1A 70mm 250mm 9x12cm (4×5″)
Dallmeyer 2A 90mm 340mm 6 1/2×4 3/4″
Dallmeyer 3A 100mm 406mm Full plate (6 1/2×8 1/2″)
Dallmeyer 4A 115mm 456mm 18x24cm (8×10″)
Dallmeyer 5A 120mm 558mm 30x40cm (12×16″)
Dallmeyer 6A 150mm 759mm 40x50cm (16×20″)

 

Dallmeyer A D Series petzval