Steinheil Orthostigmat 140mm 黃銅鏡頭

Steinheil Orthostigmat 140mm brass lens (Germany, 1898)

antique brass lens from the renowned German maker Steinheil, established in Munich in 1854
from 1898 according its serial number

engravings:

Steinheil Munich Paris
Nº 44427
Orthostigmat
1:6,8
F=14cm
Bté. S.G.D.G.​

focal length: 140mm
diaphragm: f/6.8
iris diaphragm with antique scale marked from "4"
height (with lens hood): 45mm
frontal diameter (lens hood): 43mm
image circle: about 20cm
(enough to cover a 5x7" plate with slightly dark corners)
image circle has been taken at infinite with full aperture; at close distances and with small apertures, the image circle can increase
weight (with lens flange): 165g

symmetrical optical design (6 elements, 2 groups), it is a convertible lens: if the the frontal element is unscrewed, the lens gives double focal length and increased coverage

good condition
glasses: clean and clear, there is no fungus, haze or separation
minuscule air bubbles on the glass, as usual on lenses from those times, not affecting performance
the diaphragm is clean and free of oil
diaphragm ring moves smoothly
comes with lens flange

shipping method: Post Office or GLS (depending of your country)
registered, with track and trace on internet
NOTE: USA buyers must add the 15% of the final price as tariff for goods received from European Union.
in case you buy 2 or more lots I will combine shipping and will refund you the overpaid postage