Iris diaphragm to clip over Rollieflex viewing lens to view depth of field at different apertures. Can be used as an extinction meter. No. 350482. In leather case and original carton. Iris diaphragm for a Rolleiflex
Lancaster's Universal Lens Adaptor, heavy iris diaphragm in ally mount, maximum 2 1/4" minimum 9/16ths. Two operating keys, one locks the other adjusts. Mounted on wooden lens panel, 3 3/4" x 6 1/4". (M4066) Lancaster's Universal Lens Adaptor 1907-1917