Bausch & Lomb Date Code (serial number scheme)

[kds315*]

Up to 1942 Bausch & Lomb, Rochester USA used a numerical scheme when all of a sudden
then they changed it to some cryptic two letter + digits scheme. As far as I know only the first
letter is significant for the production date, the second is a code class for lenses, microscopes etc.

The decoding is a s follows:

A 1941 G 1963 N 1962 V 1944

B 1945 H 1959 P 1958 W 1948

C 1949 J 1955 R 1954 X 1952

D 1953 K 1951 S 1950 Y 1956

E 1957 L 1947 T 1946 Z 1960

F 1961 M 1943 U 1942

So a lens with UF 743 means a lens made in 1942 and it was the lens#743 made in that year. "F" stands for photographic lenses.
I am not sure what happended after 1960 though.

So to be complete, here the serial numbers before 1942:

1 1876 32000 1900 170000 1924
150 1877 33000 1901 175000 1924
350 1878 35000 1902 180000 1925
800 1879 40000 1903 185000 1926
1100 1880 45000 1904 190000 1926
1450 1881 52000 1905 195000 1927
1750 1882 57000 1906 200000 1928
2000 1883 63000 1907 205000 1929
2500 1884 69000 1907 215000 1929
3000 1885 76000 1909 225000 1930
3800 1886 82000 1910 230000 1931
4500 1887 86000 1911 235000 1932
5300 1888 89000 1912 240000 1934
6375 1889 95000 1913 244000 1935
7600 1890 98000 1914 247000 1935
9200 1891 104000 1915 250000 1936
10000 1892 110000 1916 260000 1937
11700 1893 120000 1917 270000 1938
13900 1894 129000 1918 280000 1939
17000 1895 135000 1919 290000 1940
20000 1896 140000 1920 300000 1940
25000 1897 148000 1921 310000 1941
28000 1898 155000 1922 320000 1942
30000 1899 160000 1923

[Seele]

Hi Klaus,

Thank you for this; although B&L lenses are not as common over here it is good information indeed; kudos to you

[Attila]

Many thanks!

[SkedAddled]

Yes, many thanks.

I also knew that Attila would sticky this one!

[Attila]

[kds315*]

Orio has listed links with such info as a sticky, maybe it would fit in there as a link.

[Shingoshi]

I found your post on another forum, and another member who is also a member there, directed me to this. I think that I'm looking at getting a 1944 Photographic lens version of the 508mm f/5.6.

VF1666R

Hopefully I've read this data correctly. Now, I only have to learn how to clean this lens properly.

Xavian-Anderson Macpherson
ShingoshiDao

EDIT: I need to know the thread size and pitch on the back of this lens in question here. Is this your standard Copal #3 mount? I now realize that even if I don't get the lens I wanted, there are still others available for sale. They're not as rare as I thought. So it won't hurt so much if I don't get it.

Thanks,
Xavian-Anderson Macpherson

[overmywaders]

I have a B&L Tessar IIb f6.3 6.25" in delightfully excellent condition that I will be using. However, the serial number is 3,240,25x which doesn't fit into the numbering shown and I am curious about its age.

The Lens Vademecum states: