Bausch & Lomb Lens Date Code

[Jim Galli]

I too am glad to have some new information about B&L numbering as I have many of their lenses. For Shingosi, a Copal 3 opens to 52mm iirc (if not someone will correct me quickly). A little rapid mathematical calculation indicates that 5.6 into 508mm would need a 100mm aperture rendering a copal 3 useless unless you want to start at f11 or so and pay for a LOT of machine work to make it happen. A Fuji 600mm lens would be a far more elegant and cheaper solution

Gotta love the internet. A thread started in 2000 finally gets some answers, sort of, in '09 that come through the back door of another site.

[Michael Roberts]

So...I have two B&L Zeiss Protar VII lenses with serial nos. 989xxx and 1189xxx that don't fit either the pre-'42 number list or the 1940's alphanumeric code....

What's up with that?

[Dan Fromm]

Michael, you're not the first to have had problems with the list. See http://www.largeformatphotography.in...ad.php?t=54143

I hope that Klaus will notice the discrepancies that have been brought forward, check his work/sources, and if necessary correct his list.

Cheers,

Dan

[c.d.ewen]

For Shingosi, a Copal 3 opens to 52mm iirc (if not someone will correct me quickly).

Jim: The Word According To Grimes is 45mm.

Michael: Me, too...see attached.

Charley

[Shingoshi]

I too am glad to have some new information about B&L numbering as I have many of their lenses. For Shingosi, a Copal 3 opens to 52mm iirc (if not someone will correct me quickly). A little rapid mathematical calculation indicates that 5.6 into 508mm would need a 100mm aperture rendering a copal 3 useless unless you want to start at f11 or so and pay for a LOT of machine work to make it happen. A Fuji 600mm lens would be a far more elegant and cheaper solution

Gotta love the internet. A thread started in 2000 finally gets some answers, sort of, in '09 that come through the back door of another site.

If I understand optics correctly, only the size of the object needs to be 100mm. And if you look at the front of this lens, you'll see that it indeed has a very large objective. However, the rear of the lens is NOT as large. For most large-format lenses, the middle of the lens has an almost wasp-like body. At least my Nikkor SW 150mm f/8.0 is that way. In fact someone had already asked a question about the shutter being used with one of these lenses. So since you have as many lenses, please instead just measure the threads on the back of the lens. I need to know what that thread size is, regardless whether I use a shutter on this lens or not.

MILLIMETERS	#0	#1	#3	 #00**
A (Hole Dia.)	34.7	41.8	65.0 	26.6
B (Thread Dia.)	32.5 	39 	62	25.5

Xavian-Anderson Macpherson
ShingoshiDao

[Dan Fromm]

Shingoshi, relative aperture (the f/number) = focal length/diameter of the entrance pupil. We often approximate the entrance pupil's diameter by the diameter of the aperture, but looking at lenses will convince you that the approximation isn't always that good.

Y'r 150/8 Nikkor's entrance pupil's diameter is 150/8 = 18.75 mm.

Y'r dream lens' entrance pupil's diameter = 508/5.6 = 90.7 mm.

A #0 shutter's iris' maximum diameter is 24 mm; # 1, 30 mm; #3, 45 mm. All shutter sizes Compur/Copal/Prontor/Seikosha standard.

US-made shutters aren't that well standardized, per http://www.skgrimes.com/ilex/index.htm an Ilex #3's max is 1.275"; #4, 1.73"; #5, 2.575". Betax #5 might be a tiny bit larger. Might, I'm not sure.

There's no standard conventional shutter that will take your dream lens' cells.

I will agree with Jim. If a lens isn't in shutter, adapters to put it in a shutter are usually prohibitively expensive. There are exceptions, yours probably isn't one. Adapters to mount a lens in front of a shutter can also be extremely expensive.

A behind-the-lens shutter might do for you. At the moment I'm having a 610/9 Apo Nikkor (entrance pupil 67.8 mm, so it won't attain f/9 in an Ilex #5) adapted to be mounted in front of a #1. The conventional solution -- "everyone" knows that my rig will severely limit coverage, but they're wrong -- is a Packard or Copal-Sinar shutter. Another unconventional solution is to convert a Speed Graphic into an "in front of the lens" shutter. Barbaric, but its been done.

Not to discourage you from dreaming, but unrealistic dreams are hard to realize. I suggest that you think hard about your goals and alternative ways to attain them, also that you learn the relevant arithmetic.

Cheers,

Dan

On re-reading your post, perhaps you're contemplating mounting a 508/5.6 in front of a large shutter. I doubt that lens' rear can easily be stuffed into any readily available shutter, also that it is threaded externally at the rear. In general LF lenses in barrel are not threaded externally at the rear. Mounting threads are usually located right behind the diaphragm. There are indeed exceptions, I have some, so there's no need to remind me that they exist. In any case, adapters are costly and you'll have to plan to support the lens. If you don't support it, there's a very real risk that it will break the shutter its hung from or break your camera's front standard.

[Shingoshi]

I actually had no intention of mounting this lens in a shutter at all. But rather than really stir up other issues, I'm not even going to say what or how I intend to use it. The only thing that's important here, is that I NEED to know the thread size on the back of the lens. I see the threads there. But since I don't yet have the lens, I can't measure it.

So please someone, measure the threads on the back of the lens. I also wouldn't mind knowing what the filter size is as well. BTW, I also have a Sinar. But I don't have the shutter you're talking about. I was trying to find my old parts catalog to find the numbers for the Digital Shutter. And again, not for the shutter sake, but for the mounting system it used. I'm looking for something that I can mount this lens into. The old Sinar Handy, Alpa and others had a conical piece that you would mount your lens into. But I'm not finding what I'm looking for.

Thank you!
Xavian-Anderson Macpherson
Shingoshi

[Shingoshi]

So many lenses, and no tape measure? Such a cruel world we live in!

I don't need a lecture. I need the measurements.

Xavian-Anderson Macpherson
ShingoshiDao

[Jim Graves]

Given the earlier issue in this thread indicating a reluctance to share this information, I thought ... just in case the other forum's archives went kaput ... it would be a good idea to post the underlying information here also:

"Up to 1942, Bausch & Lomb used a numerical scheme but then changed to a 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 happened 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"
_________________ Klaus

[Dan Fromm]

Jim, Klaus' pre-1942 serial numbers are inconsistent with the lenses posters here and in this http://www.largeformatphotography.in...ad.php?t=54143 thread own. You're doing us no favors by spreading misinformation.

Don't tell me that misinformation is better than none.

Yours with a hearty arrgh!,

Dan