A. M. lens: Who made it? "W W" code = ???

[Carsten Wolff]

Thanks, Dan and others!

[tuant]

For the Dagors, does A.M still mean British Air Ministry? I have a Dagor in that version. Since A.M products were made for the Air Force, doesn't it mean that the products are of better quality than those none A.M. versions? Thanks!

Tuant

[IanG]

Dagors marked Goerz Am Opt or similar mean they were made by Goerz American Optical which was by then an independent company owned by CP Goerz sons in the US.

Ironically the US forces were using Goerz Am Opt lenses etc in WWI while the Germans were using similar made by CP Goerz, Berlin.

Ian

[Sevo]

For the Dagors, does A.M still mean British Air Ministry? I have a Dagor in that version. Since A.M products were made for the Air Force, doesn't it mean that the products are of better quality than those none A.M. versions? Thanks!

As has been pointed out, there have been other meanings of "Am", especially concerning Goerz.

Air Ministry labelled lenses were made for the British Air Ministry in WWII (the Air Ministry was not established until after WWI), under special laws that allowed them to pool the British optical industry. Essentially all production facilities could be requested to make any design, regardless of patents and competitor status.

A.M lenses (and indeed all aerial lenses made by all parties in WWII) were of worse quality than the corresponding peace-time versions - thanks to materials shortages, an increase in production well beyond the numbers they had an experienced workforce for, and the relatively low longevity requirements for items installed on planes which were statistically expected to be shot down within weeks or months.

[IanG]

The Air Ministry was formed during WWI in 1917, although the necessary act of Parliament went into force at the beginning of January 1918. So some AM lenses are very much earlier than WWII.

Ian

[tuant]

As has been pointed out, there have been other meanings of "Am", especially concerning Goerz.


A.M lenses (and indeed all aerial lenses made by all parties in WWII) were of worse quality than the corresponding peace-time versions - thanks to materials shortages, an increase in production well beyond the numbers they had an experienced workforce for, and the relatively low longevity requirements for items installed on planes which were statistically expected to be shot down within weeks or months.

Thanks, guys! That means I should avoid AM lenses in the future:-)

[Dan Fromm]

Thanks, guys! That means I should avoid AM lenses in the future:-)

I don't see why.

The RAF didn't stop buying aerial cameras and lenses to fit them when WW-II ended. I have a couple of post-war TTH A.M. lenses that are outstanding. 4"/2.0 Anastigmat (2 1/4" x 2 1/4") and 12"/4 Telephoto. The 4" covers 2x3 wide open and is better from f/4.5 down than the highly regarded 101/4.5 Ektar. Bigger and heavier, though. The VM says the 12" just covers 4x5. It is the longest lens that's comfortable on a 2x3 Speed Graphic but doesn't put image at the ends of the frame because of vignetting by the bellows.

Other air forces bought aerial cameras and lenses for them too. USAF, for one. Many, not all, of the lenses that the USAF flew are very good and some (far from all) of them can be adapted to modern cameras.

That said, I'd be leery of cruddy old brand-X 8"/2.9 Pentacs.

In my opinion, which is not based on much good data, when a lens, e.g., the 38/4.5 Biogon, was sold to an aerial camera manufacturer such as AGI and to civilians all buyers got the same quality. AGI may, however, have had more stringent acceptance tests than, say, Hasselblad or Alpa. Same goes for the Zeiss lenses supplied for Agiflites; these were also mounted in for Hasselblad and Rollei.

That said, some of the lenses that armed forces bought were definitely second best. On this point, look up what Leicanuts have had to say about M-mount lenses made to military specifications.

There's some evidence that Soviet lens makers, purveyors to east-bloc air forces, had as much difficulty with quality control as they did with lenses made for civilians. I have only one Soviet aerial camera lens, a 100/2.5 Uran-27. Its ok; if I had to use it instead of the 4"/2.0 TTH I wouldn't feel sorry for myself but it isn't up to the TTH.

[Carsten Wolff]

I just pretty much confirmed that it is indeed a Ross Express Wide Angle. The same lens was often fitted to 6x18cm Vought-Solar Aircraft Torpedo cameras (San Diego) in the '40s. Thanks again.

[Ian Greenhalgh]

I have two of these lenses, f4.5 5". They are a 4/4 double gauss design. One of mine has the WW code and the s/n 27473, the other has no code but the s/n 26705.

They are not Ross Wide Angle Xpres, I have two of those as well, and those are a 6/4 plasmat with much larger glass.

Both the Ross WA Xpres and this mystery 4.5/5" were fitted to the Vought-Solar torpedo training camera.

Here is an example of the 4.5/5" fitted to said camera:

http://www.flickr.com/photos/heritag...57626099002858

Here you can see a Ross WA Xpress 4/5" on the left and a mystery 4.5/5" on the right:





I've just managed to cram the cells from one of the 4.5/5" into a spare Alphax #3 I had to hand so I'll try it out on 5x7 shortly.

[Pete Watkins]

NO.Co = National Optical Company. As far as I've managed to find out this outfit was set up in Leicester (the same Leicester where the TT&H factory is)in the early part of the WW2 to produce lenses for the military. A lot of the staff were from TT&H. I have no idea when production started or finished.
Pete.